linux_dsm_epyc7002/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c

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/*
* Amlogic Meson8b and GXBB DWMAC glue layer
*
* Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/ethtool.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/of_net.h>
#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/stmmac.h>
#include "stmmac_platform.h"
#define PRG_ETH0 0x0
#define PRG_ETH0_RGMII_MODE BIT(0)
/* mux to choose between fclk_div2 (bit unset) and mpll2 (bit set) */
#define PRG_ETH0_CLK_M250_SEL_SHIFT 4
#define PRG_ETH0_CLK_M250_SEL_MASK GENMASK(4, 4)
#define PRG_ETH0_TXDLY_SHIFT 5
#define PRG_ETH0_TXDLY_MASK GENMASK(6, 5)
/* divider for the result of m250_sel */
#define PRG_ETH0_CLK_M250_DIV_SHIFT 7
#define PRG_ETH0_CLK_M250_DIV_WIDTH 3
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
#define PRG_ETH0_RGMII_TX_CLK_EN 10
#define PRG_ETH0_INVERTED_RMII_CLK BIT(11)
#define PRG_ETH0_TX_AND_PHY_REF_CLK BIT(12)
#define MUX_CLK_NUM_PARENTS 2
struct meson8b_dwmac {
struct platform_device *pdev;
void __iomem *regs;
phy_interface_t phy_mode;
struct clk_mux m250_mux;
struct clk *m250_mux_clk;
struct clk *m250_mux_parent[MUX_CLK_NUM_PARENTS];
struct clk_divider m250_div;
struct clk *m250_div_clk;
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
struct clk_fixed_factor fixed_div2;
struct clk *fixed_div2_clk;
struct clk_gate rgmii_tx_en;
struct clk *rgmii_tx_en_clk;
u32 tx_delay_ns;
};
static void meson8b_dwmac_mask_bits(struct meson8b_dwmac *dwmac, u32 reg,
u32 mask, u32 value)
{
u32 data;
data = readl(dwmac->regs + reg);
data &= ~mask;
data |= (value & mask);
writel(data, dwmac->regs + reg);
}
static int meson8b_init_rgmii_tx_clk(struct meson8b_dwmac *dwmac)
{
struct clk_init_data init;
int i, ret;
struct device *dev = &dwmac->pdev->dev;
char clk_name[32];
const char *clk_div_parents[1];
const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
/* get the mux parents from DT */
for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
char name[16];
snprintf(name, sizeof(name), "clkin%d", i);
dwmac->m250_mux_parent[i] = devm_clk_get(dev, name);
if (IS_ERR(dwmac->m250_mux_parent[i])) {
ret = PTR_ERR(dwmac->m250_mux_parent[i]);
if (ret != -EPROBE_DEFER)
dev_err(dev, "Missing clock %s\n", name);
return ret;
}
mux_parent_names[i] =
__clk_get_name(dwmac->m250_mux_parent[i]);
}
/* create the m250_mux */
snprintf(clk_name, sizeof(clk_name), "%s#m250_sel", dev_name(dev));
init.name = clk_name;
init.ops = &clk_mux_ops;
init.flags = 0;
init.parent_names = mux_parent_names;
init.num_parents = MUX_CLK_NUM_PARENTS;
dwmac->m250_mux.reg = dwmac->regs + PRG_ETH0;
dwmac->m250_mux.shift = PRG_ETH0_CLK_M250_SEL_SHIFT;
dwmac->m250_mux.mask = PRG_ETH0_CLK_M250_SEL_MASK;
dwmac->m250_mux.flags = 0;
dwmac->m250_mux.table = NULL;
dwmac->m250_mux.hw.init = &init;
dwmac->m250_mux_clk = devm_clk_register(dev, &dwmac->m250_mux.hw);
if (WARN_ON(IS_ERR(dwmac->m250_mux_clk)))
return PTR_ERR(dwmac->m250_mux_clk);
/* create the m250_div */
snprintf(clk_name, sizeof(clk_name), "%s#m250_div", dev_name(dev));
init.name = devm_kstrdup(dev, clk_name, GFP_KERNEL);
init.ops = &clk_divider_ops;
init.flags = CLK_SET_RATE_PARENT;
clk_div_parents[0] = __clk_get_name(dwmac->m250_mux_clk);
init.parent_names = clk_div_parents;
init.num_parents = ARRAY_SIZE(clk_div_parents);
dwmac->m250_div.reg = dwmac->regs + PRG_ETH0;
dwmac->m250_div.shift = PRG_ETH0_CLK_M250_DIV_SHIFT;
dwmac->m250_div.width = PRG_ETH0_CLK_M250_DIV_WIDTH;
dwmac->m250_div.hw.init = &init;
dwmac->m250_div.flags = CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO;
dwmac->m250_div_clk = devm_clk_register(dev, &dwmac->m250_div.hw);
if (WARN_ON(IS_ERR(dwmac->m250_div_clk)))
return PTR_ERR(dwmac->m250_div_clk);
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
/* create the fixed_div2 */
snprintf(clk_name, sizeof(clk_name), "%s#fixed_div2", dev_name(dev));
init.name = devm_kstrdup(dev, clk_name, GFP_KERNEL);
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
init.ops = &clk_fixed_factor_ops;
init.flags = CLK_SET_RATE_PARENT;
clk_div_parents[0] = __clk_get_name(dwmac->m250_div_clk);
init.parent_names = clk_div_parents;
init.num_parents = ARRAY_SIZE(clk_div_parents);
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
dwmac->fixed_div2.mult = 1;
dwmac->fixed_div2.div = 2;
dwmac->fixed_div2.hw.init = &init;
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
dwmac->fixed_div2_clk = devm_clk_register(dev, &dwmac->fixed_div2.hw);
if (WARN_ON(IS_ERR(dwmac->fixed_div2_clk)))
return PTR_ERR(dwmac->fixed_div2_clk);
/* create the rgmii_tx_en */
init.name = devm_kasprintf(dev, GFP_KERNEL, "%s#rgmii_tx_en",
dev_name(dev));
init.ops = &clk_gate_ops;
init.flags = CLK_SET_RATE_PARENT;
clk_div_parents[0] = __clk_get_name(dwmac->fixed_div2_clk);
init.parent_names = clk_div_parents;
init.num_parents = ARRAY_SIZE(clk_div_parents);
dwmac->rgmii_tx_en.reg = dwmac->regs + PRG_ETH0;
dwmac->rgmii_tx_en.bit_idx = PRG_ETH0_RGMII_TX_CLK_EN;
dwmac->rgmii_tx_en.hw.init = &init;
dwmac->rgmii_tx_en_clk = devm_clk_register(dev,
&dwmac->rgmii_tx_en.hw);
if (WARN_ON(IS_ERR(dwmac->rgmii_tx_en_clk)))
return PTR_ERR(dwmac->rgmii_tx_en_clk);
return 0;
}
static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac)
{
int ret;
u8 tx_dly_val = 0;
switch (dwmac->phy_mode) {
case PHY_INTERFACE_MODE_RGMII:
case PHY_INTERFACE_MODE_RGMII_RXID:
/* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where
* 8ns are exactly one cycle of the 125MHz RGMII TX clock):
* 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3
*/
tx_dly_val = dwmac->tx_delay_ns >> 1;
/* fall through */
case PHY_INTERFACE_MODE_RGMII_ID:
case PHY_INTERFACE_MODE_RGMII_TXID:
/* enable RGMII mode */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_RGMII_MODE,
PRG_ETH0_RGMII_MODE);
/* only relevant for RMII mode -> disable in RGMII mode */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
PRG_ETH0_INVERTED_RMII_CLK, 0);
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK,
tx_dly_val << PRG_ETH0_TXDLY_SHIFT);
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
/* Configure the 125MHz RGMII TX clock, the IP block changes
* the output automatically (= without us having to configure
* a register) based on the line-speed (125MHz for Gbit speeds,
* 25MHz for 100Mbit/s and 2.5MHz for 10Mbit/s).
*/
ret = clk_set_rate(dwmac->rgmii_tx_en_clk, 125 * 1000 * 1000);
if (ret) {
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
dev_err(&dwmac->pdev->dev,
"failed to set RGMII TX clock\n");
return ret;
}
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
ret = clk_prepare_enable(dwmac->rgmii_tx_en_clk);
if (ret) {
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
dev_err(&dwmac->pdev->dev,
"failed to enable the RGMII TX clock\n");
return ret;
}
break;
case PHY_INTERFACE_MODE_RMII:
/* disable RGMII mode -> enables RMII mode */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_RGMII_MODE,
0);
/* invert internal clk_rmii_i to generate 25/2.5 tx_rx_clk */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0,
PRG_ETH0_INVERTED_RMII_CLK,
PRG_ETH0_INVERTED_RMII_CLK);
/* TX clock delay cannot be configured in RMII mode */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK,
0);
break;
default:
dev_err(&dwmac->pdev->dev, "unsupported phy-mode %s\n",
phy_modes(dwmac->phy_mode));
return -EINVAL;
}
/* enable TX_CLK and PHY_REF_CLK generator */
meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TX_AND_PHY_REF_CLK,
PRG_ETH0_TX_AND_PHY_REF_CLK);
return 0;
}
static int meson8b_dwmac_probe(struct platform_device *pdev)
{
struct plat_stmmacenet_data *plat_dat;
struct stmmac_resources stmmac_res;
struct resource *res;
struct meson8b_dwmac *dwmac;
int ret;
ret = stmmac_get_platform_resources(pdev, &stmmac_res);
if (ret)
return ret;
plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
if (IS_ERR(plat_dat))
return PTR_ERR(plat_dat);
dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
if (!dwmac) {
ret = -ENOMEM;
goto err_remove_config_dt;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
dwmac->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dwmac->regs)) {
ret = PTR_ERR(dwmac->regs);
goto err_remove_config_dt;
}
dwmac->pdev = pdev;
dwmac->phy_mode = of_get_phy_mode(pdev->dev.of_node);
if (dwmac->phy_mode < 0) {
dev_err(&pdev->dev, "missing phy-mode property\n");
ret = -EINVAL;
goto err_remove_config_dt;
}
/* use 2ns as fallback since this value was previously hardcoded */
if (of_property_read_u32(pdev->dev.of_node, "amlogic,tx-delay-ns",
&dwmac->tx_delay_ns))
dwmac->tx_delay_ns = 2;
ret = meson8b_init_rgmii_tx_clk(dwmac);
if (ret)
goto err_remove_config_dt;
ret = meson8b_init_prg_eth(dwmac);
if (ret)
goto err_remove_config_dt;
plat_dat->bsp_priv = dwmac;
ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
if (ret)
goto err_clk_disable;
return 0;
err_clk_disable:
if (phy_interface_mode_is_rgmii(dwmac->phy_mode))
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
clk_disable_unprepare(dwmac->rgmii_tx_en_clk);
err_remove_config_dt:
stmmac_remove_config_dt(pdev, plat_dat);
return ret;
}
static int meson8b_dwmac_remove(struct platform_device *pdev)
{
struct meson8b_dwmac *dwmac = get_stmmac_bsp_priv(&pdev->dev);
if (phy_interface_mode_is_rgmii(dwmac->phy_mode))
net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration Tests (using an oscilloscope and an Odroid-C1 board with a RTL8211F RGMII PHY) have shown that the PRG_ETH0 register behaves as follows: - bit 4 is a mux to choose between two parent clocks. according to the public S805 datasheet the only supported parent clock is MPLL2 (this was not verified using the oscilloscope). The public S805/S905 datasheet claims that this bit is reserved. - bits 9:7 control a one-based divider (register value 1 means "divide by 1", etc.) for the input clock. we call this clock the "m250_div" clock because it's value is always supposed to be (close to) 250MHz (see below for an explanation). The description in the public S805/S905 datasheet is a bit cryptic, but it comes down to "input clock = 250MHz * value" (which could also be expressed as "250MHz = input clock / value") - there seems to be an internal fixed divide-by-2 clock which takes the output from the m250_div and divides it by 2. This is not unusual on Amlogic SoCs, since the SDIO (MMC) driver also uses an internal fixed divide-by-2 clock. This is not documented in the public S805/S905 datasheet - bit 10 controls a gate clock which enables or disables the RGMII TX clock (which is an output on the MAC/SoC and an input in the PHY). we call this the "rgmii_tx_en" clock. if this bit is set to "0" the RGMII TX clock output is close to 0 The description for this bit in the public S805/S905 datasheet is "Generate 25MHz clock for PHY". Based on these tests it's believed that this is wrong, and should probably read "Generate the 125MHz RGMII TX clock for the PHY" - the RGMII TX clock has to be set to 125MHz - the IP block adjusts the output (automatically) depending on the line speed (RGMII specifies that Gbit connections use a 125MHz clock, 100Mbit/s connections use a 25MHz clock and 10Mbit/s connections use a 2.5MHz clock. only Gbit and 100Mbit/s were tested with an oscilloscope). Due to the requirement that this clock always has to be set to 125MHz and due to the fixed divide-by-2 parent clock this means that m250_div will always end up with a rate of (close to) 250MHz. - bits 6:5 are the TX delay, which is also named "clock phase" in some of Amlogic's older GPL kernel sources. The PHY also has an XTAL_IN pin where a 25MHz clock has to be provided. Tests with the oscilloscope have shown that this is routed to a crystal right next to the RTL8211F PHY. The same seems to be true on the Khadas VIM2 (which uses a GXM SoC) board - however the 25MHz crystal is on the other side of the PCB there. This updates the clocks in the dwmac-meson8b driver by replacing the "m25_div" with the "rgmii_tx_en" clock and additionally introducing a fixed divide-by-2 clock between "m250_div" and "rgmii_tx_en". Now we also need to set a frequency of 125MHz on the RGMII clock (opposed to the 25MHz we set before, with that non-existing divide-by-5-or-10 divider). Special thanks go to Linus Lüssing for testing the various bits and checking the results with an oscilloscope on his Odroid-C1! Fixes: 566e8251625304 ("net: stmmac: add a glue driver for the Amlogic Meson 8b / GXBB DWMAC") Reported-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16 00:10:13 +07:00
clk_disable_unprepare(dwmac->rgmii_tx_en_clk);
return stmmac_pltfr_remove(pdev);
}
static const struct of_device_id meson8b_dwmac_match[] = {
{ .compatible = "amlogic,meson8b-dwmac" },
{ .compatible = "amlogic,meson-gxbb-dwmac" },
{ }
};
MODULE_DEVICE_TABLE(of, meson8b_dwmac_match);
static struct platform_driver meson8b_dwmac_driver = {
.probe = meson8b_dwmac_probe,
.remove = meson8b_dwmac_remove,
.driver = {
.name = "meson8b-dwmac",
.pm = &stmmac_pltfr_pm_ops,
.of_match_table = meson8b_dwmac_match,
},
};
module_platform_driver(meson8b_dwmac_driver);
MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
MODULE_DESCRIPTION("Amlogic Meson8b and GXBB DWMAC glue layer");
MODULE_LICENSE("GPL v2");