AuxXxilium/linux_dsm_epyc7002
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linux_dsm_epyc7002/drivers/i2c/busses/i2c-xlp9xx.c
Tanmay Jagdale 254df038e5 i2c: xlp9xx: ACPI support for I2C clients 
The ACPI companion of the adapter has to be set for I2C controller
code to read and attach the slave devices described in the ACPI table
with the I2CSerialBus resource descriptor. Used ACPI_COMPANION_SET
macro to set this.

Signed-off-by: Tanmay Jagdale <tanmay.jagdale@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-18 02:25:38 +01:00

455 lines
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/*
* Copyright (c) 2003-2015 Broadcom Corporation
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#define XLP9XX_I2C_DIV 0x0
#define XLP9XX_I2C_CTRL 0x1
#define XLP9XX_I2C_CMD 0x2
#define XLP9XX_I2C_STATUS 0x3
#define XLP9XX_I2C_MTXFIFO 0x4
#define XLP9XX_I2C_MRXFIFO 0x5
#define XLP9XX_I2C_MFIFOCTRL 0x6
#define XLP9XX_I2C_STXFIFO 0x7
#define XLP9XX_I2C_SRXFIFO 0x8
#define XLP9XX_I2C_SFIFOCTRL 0x9
#define XLP9XX_I2C_SLAVEADDR 0xA
#define XLP9XX_I2C_OWNADDR 0xB
#define XLP9XX_I2C_FIFOWCNT 0xC
#define XLP9XX_I2C_INTEN 0xD
#define XLP9XX_I2C_INTST 0xE
#define XLP9XX_I2C_WAITCNT 0xF
#define XLP9XX_I2C_TIMEOUT 0X10
#define XLP9XX_I2C_GENCALLADDR 0x11
#define XLP9XX_I2C_CMD_START BIT(7)
#define XLP9XX_I2C_CMD_STOP BIT(6)
#define XLP9XX_I2C_CMD_READ BIT(5)
#define XLP9XX_I2C_CMD_WRITE BIT(4)
#define XLP9XX_I2C_CMD_ACK BIT(3)
#define XLP9XX_I2C_CTRL_MCTLEN_SHIFT 16
#define XLP9XX_I2C_CTRL_MCTLEN_MASK 0xffff0000
#define XLP9XX_I2C_CTRL_RST BIT(8)
#define XLP9XX_I2C_CTRL_EN BIT(6)
#define XLP9XX_I2C_CTRL_MASTER BIT(4)
#define XLP9XX_I2C_CTRL_FIFORD BIT(1)
#define XLP9XX_I2C_CTRL_ADDMODE BIT(0)
#define XLP9XX_I2C_INTEN_NACKADDR BIT(25)
#define XLP9XX_I2C_INTEN_SADDR BIT(13)
#define XLP9XX_I2C_INTEN_DATADONE BIT(12)
#define XLP9XX_I2C_INTEN_ARLOST BIT(11)
#define XLP9XX_I2C_INTEN_MFIFOFULL BIT(4)
#define XLP9XX_I2C_INTEN_MFIFOEMTY BIT(3)
#define XLP9XX_I2C_INTEN_MFIFOHI BIT(2)
#define XLP9XX_I2C_INTEN_BUSERR BIT(0)
#define XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT 8
#define XLP9XX_I2C_MFIFOCTRL_LOTH_SHIFT 0
#define XLP9XX_I2C_MFIFOCTRL_RST BIT(16)
#define XLP9XX_I2C_SLAVEADDR_RW BIT(0)
#define XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT 1
#define XLP9XX_I2C_IP_CLK_FREQ 133000000UL
#define XLP9XX_I2C_DEFAULT_FREQ 100000
#define XLP9XX_I2C_HIGH_FREQ 400000
#define XLP9XX_I2C_FIFO_SIZE 0x80U
#define XLP9XX_I2C_TIMEOUT_MS 1000
#define XLP9XX_I2C_FIFO_WCNT_MASK 0xff
#define XLP9XX_I2C_STATUS_ERRMASK (XLP9XX_I2C_INTEN_ARLOST | \
XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_BUSERR)
struct xlp9xx_i2c_dev {
struct device *dev;
struct i2c_adapter adapter;
struct completion msg_complete;
int irq;
bool msg_read;
u32 __iomem *base;
u32 msg_buf_remaining;
u32 msg_len;
u32 clk_hz;
u32 msg_err;
u8 *msg_buf;
};
static inline void xlp9xx_write_i2c_reg(struct xlp9xx_i2c_dev *priv,
unsigned long reg, u32 val)
{
writel(val, priv->base + reg);
}
static inline u32 xlp9xx_read_i2c_reg(struct xlp9xx_i2c_dev *priv,
unsigned long reg)
{
return readl(priv->base + reg);
}
static void xlp9xx_i2c_mask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
{
u32 inten;
inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) & ~mask;
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
}
static void xlp9xx_i2c_unmask_irq(struct xlp9xx_i2c_dev *priv, u32 mask)
{
u32 inten;
inten = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTEN) | mask;
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, inten);
}
static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv)
{
u32 thres;
thres = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT);
}
static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
{
u32 len, i;
u8 *buf = priv->msg_buf;
len = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
for (i = 0; i < len; i++)
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MTXFIFO, buf[i]);
priv->msg_buf_remaining -= len;
priv->msg_buf += len;
}
static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
{
u32 len, i;
u8 *buf = priv->msg_buf;
len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
XLP9XX_I2C_FIFO_WCNT_MASK;
len = min(priv->msg_buf_remaining, len);
for (i = 0; i < len; i++, buf++)
*buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
priv->msg_buf_remaining -= len;
priv->msg_buf = buf;
if (priv->msg_buf_remaining)
xlp9xx_i2c_update_rx_fifo_thres(priv);
}
static irqreturn_t xlp9xx_i2c_isr(int irq, void *dev_id)
{
struct xlp9xx_i2c_dev *priv = dev_id;
u32 status;
status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_INTST);
if (status == 0)
return IRQ_NONE;
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTST, status);
if (status & XLP9XX_I2C_STATUS_ERRMASK) {
priv->msg_err = status;
goto xfer_done;
}
/* SADDR ACK for SMBUS_QUICK */
if ((status & XLP9XX_I2C_INTEN_SADDR) && (priv->msg_len == 0))
goto xfer_done;
if (!priv->msg_read) {
if (status & XLP9XX_I2C_INTEN_MFIFOEMTY) {
/* TX FIFO got empty, fill it up again */
if (priv->msg_buf_remaining)
xlp9xx_i2c_fill_tx_fifo(priv);
else
xlp9xx_i2c_mask_irq(priv,
XLP9XX_I2C_INTEN_MFIFOEMTY);
}
} else {
if (status & (XLP9XX_I2C_INTEN_DATADONE |
XLP9XX_I2C_INTEN_MFIFOHI)) {
/* data is in FIFO, read it */
if (priv->msg_buf_remaining)
xlp9xx_i2c_drain_rx_fifo(priv);
}
}
/* Transfer complete */
if (status & XLP9XX_I2C_INTEN_DATADONE)
goto xfer_done;
return IRQ_HANDLED;
xfer_done:
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
complete(&priv->msg_complete);
return IRQ_HANDLED;
}
static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv)
{
u32 prescale;
/*
* The controller uses 5 * SCL clock internally.
* So prescale value should be divided by 5.
*/
prescale = DIV_ROUND_UP(XLP9XX_I2C_IP_CLK_FREQ, priv->clk_hz);
prescale = ((prescale - 8) / 5) - 1;
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_RST);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_EN |
XLP9XX_I2C_CTRL_MASTER);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_DIV, prescale);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
return 0;
}
static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
int last_msg)
{
unsigned long timeleft;
u32 intr_mask, cmd, val;
priv->msg_buf = msg->buf;
priv->msg_buf_remaining = priv->msg_len = msg->len;
priv->msg_err = 0;
priv->msg_read = (msg->flags & I2C_M_RD);
reinit_completion(&priv->msg_complete);
/* Reset FIFO */
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
XLP9XX_I2C_MFIFOCTRL_RST);
/* set FIFO threshold if reading */
if (priv->msg_read)
xlp9xx_i2c_update_rx_fifo_thres(priv);
/* set slave addr */
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_SLAVEADDR,
(msg->addr << XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT) |
(priv->msg_read ? XLP9XX_I2C_SLAVEADDR_RW : 0));
/* Build control word for transfer */
val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
if (!priv->msg_read)
val &= ~XLP9XX_I2C_CTRL_FIFORD;
else
val |= XLP9XX_I2C_CTRL_FIFORD; /* read */
if (msg->flags & I2C_M_TEN)
val |= XLP9XX_I2C_CTRL_ADDMODE; /* 10-bit address mode*/
else
val &= ~XLP9XX_I2C_CTRL_ADDMODE;
/* set data length to be transferred */
val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
(msg->len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
/* fill fifo during tx */
if (!priv->msg_read)
xlp9xx_i2c_fill_tx_fifo(priv);
/* set interrupt mask */
intr_mask = (XLP9XX_I2C_INTEN_ARLOST | XLP9XX_I2C_INTEN_BUSERR |
XLP9XX_I2C_INTEN_NACKADDR | XLP9XX_I2C_INTEN_DATADONE);
if (priv->msg_read) {
intr_mask |= XLP9XX_I2C_INTEN_MFIFOHI;
if (msg->len == 0)
intr_mask |= XLP9XX_I2C_INTEN_SADDR;
} else {
if (msg->len == 0)
intr_mask |= XLP9XX_I2C_INTEN_SADDR;
else
intr_mask |= XLP9XX_I2C_INTEN_MFIFOEMTY;
}
xlp9xx_i2c_unmask_irq(priv, intr_mask);
/* set cmd reg */
cmd = XLP9XX_I2C_CMD_START;
cmd |= (priv->msg_read ? XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE);
if (last_msg)
cmd |= XLP9XX_I2C_CMD_STOP;
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, cmd);
timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS);
timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft);
if (priv->msg_err) {
dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err);
if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR)
xlp9xx_i2c_init(priv);
return -EIO;
}
if (timeleft == 0) {
dev_dbg(priv->dev, "i2c transfer timed out!\n");
xlp9xx_i2c_init(priv);
return -ETIMEDOUT;
}
return 0;
}
static int xlp9xx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
int i, ret;
struct xlp9xx_i2c_dev *priv = i2c_get_adapdata(adap);
for (i = 0; i < num; i++) {
ret = xlp9xx_i2c_xfer_msg(priv, &msgs[i], i == num - 1);
if (ret != 0)
return ret;
}
return num;
}
static u32 xlp9xx_i2c_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C |
I2C_FUNC_10BIT_ADDR;
}
static struct i2c_algorithm xlp9xx_i2c_algo = {
.master_xfer = xlp9xx_i2c_xfer,
.functionality = xlp9xx_i2c_functionality,
};
static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
struct xlp9xx_i2c_dev *priv)
{
u32 freq;
int err;
err = device_property_read_u32(&pdev->dev, "clock-frequency", &freq);
if (err) {
freq = XLP9XX_I2C_DEFAULT_FREQ;
dev_dbg(&pdev->dev, "using default frequency %u\n", freq);
} else if (freq == 0 || freq > XLP9XX_I2C_HIGH_FREQ) {
dev_warn(&pdev->dev, "invalid frequency %u, using default\n",
freq);
freq = XLP9XX_I2C_DEFAULT_FREQ;
}
priv->clk_hz = freq;
return 0;
}
static int xlp9xx_i2c_probe(struct platform_device *pdev)
{
struct xlp9xx_i2c_dev *priv;
struct resource *res;
int err = 0;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->irq = platform_get_irq(pdev, 0);
if (priv->irq <= 0) {
dev_err(&pdev->dev, "invalid irq!\n");
return priv->irq;
}
xlp9xx_i2c_get_frequency(pdev, priv);
xlp9xx_i2c_init(priv);
err = devm_request_irq(&pdev->dev, priv->irq, xlp9xx_i2c_isr, 0,
pdev->name, priv);
if (err) {
dev_err(&pdev->dev, "IRQ request failed!\n");
return err;
}
init_completion(&priv->msg_complete);
priv->adapter.dev.parent = &pdev->dev;
priv->adapter.algo = &xlp9xx_i2c_algo;
ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
priv->adapter.dev.of_node = pdev->dev.of_node;
priv->dev = &pdev->dev;
snprintf(priv->adapter.name, sizeof(priv->adapter.name), "xlp9xx-i2c");
i2c_set_adapdata(&priv->adapter, priv);
err = i2c_add_adapter(&priv->adapter);
if (err)
return err;
platform_set_drvdata(pdev, priv);
dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);
return 0;
}
static int xlp9xx_i2c_remove(struct platform_device *pdev)
{
struct xlp9xx_i2c_dev *priv;
priv = platform_get_drvdata(pdev);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_INTEN, 0);
synchronize_irq(priv->irq);
i2c_del_adapter(&priv->adapter);
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, 0);
return 0;
}
static const struct of_device_id xlp9xx_i2c_of_match[] = {
{ .compatible = "netlogic,xlp980-i2c", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, xlp9xx_i2c_of_match);
#ifdef CONFIG_ACPI
static const struct acpi_device_id xlp9xx_i2c_acpi_ids[] = {
{"BRCM9007", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, xlp9xx_i2c_acpi_ids);
#endif
static struct platform_driver xlp9xx_i2c_driver = {
.probe = xlp9xx_i2c_probe,
.remove = xlp9xx_i2c_remove,
.driver = {
.name = "xlp9xx-i2c",
.of_match_table = xlp9xx_i2c_of_match,
.acpi_match_table = ACPI_PTR(xlp9xx_i2c_acpi_ids),
},
};
module_platform_driver(xlp9xx_i2c_driver);
MODULE_AUTHOR("Subhendu Sekhar Behera <sbehera@broadcom.com>");
MODULE_DESCRIPTION("XLP9XX/5XX I2C Bus Controller Driver");
MODULE_LICENSE("GPL v2");
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