linux_dsm_epyc7002/arch/arm/mach-imx/clk-pllv2.c
Sascha Hauer 9ca41bccc3 ARM i.MX pllv2: make round_rate accurate
in round_rate we made the assumption that we can set arbitrary
frequencies and thus returned the input rate. This is not correct,
for certain frequencies after setting a frequency with set_rate,
recalc_rate will return different values. To fix this, introduce
set_rate/recalc_rate functions which work on variables instead
of registers directly. This way we can call these in round_rate
to get the exact rate which we would get if we call set_rate
with this value.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-06-04 15:23:47 +02:00

267 lines
6.3 KiB
C

#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <asm/div64.h>
#include "clk.h"
#define to_clk_pllv2(clk) (container_of(clk, struct clk_pllv2, clk))
/* PLL Register Offsets */
#define MXC_PLL_DP_CTL 0x00
#define MXC_PLL_DP_CONFIG 0x04
#define MXC_PLL_DP_OP 0x08
#define MXC_PLL_DP_MFD 0x0C
#define MXC_PLL_DP_MFN 0x10
#define MXC_PLL_DP_MFNMINUS 0x14
#define MXC_PLL_DP_MFNPLUS 0x18
#define MXC_PLL_DP_HFS_OP 0x1C
#define MXC_PLL_DP_HFS_MFD 0x20
#define MXC_PLL_DP_HFS_MFN 0x24
#define MXC_PLL_DP_MFN_TOGC 0x28
#define MXC_PLL_DP_DESTAT 0x2c
/* PLL Register Bit definitions */
#define MXC_PLL_DP_CTL_MUL_CTRL 0x2000
#define MXC_PLL_DP_CTL_DPDCK0_2_EN 0x1000
#define MXC_PLL_DP_CTL_DPDCK0_2_OFFSET 12
#define MXC_PLL_DP_CTL_ADE 0x800
#define MXC_PLL_DP_CTL_REF_CLK_DIV 0x400
#define MXC_PLL_DP_CTL_REF_CLK_SEL_MASK (3 << 8)
#define MXC_PLL_DP_CTL_REF_CLK_SEL_OFFSET 8
#define MXC_PLL_DP_CTL_HFSM 0x80
#define MXC_PLL_DP_CTL_PRE 0x40
#define MXC_PLL_DP_CTL_UPEN 0x20
#define MXC_PLL_DP_CTL_RST 0x10
#define MXC_PLL_DP_CTL_RCP 0x8
#define MXC_PLL_DP_CTL_PLM 0x4
#define MXC_PLL_DP_CTL_BRM0 0x2
#define MXC_PLL_DP_CTL_LRF 0x1
#define MXC_PLL_DP_CONFIG_BIST 0x8
#define MXC_PLL_DP_CONFIG_SJC_CE 0x4
#define MXC_PLL_DP_CONFIG_AREN 0x2
#define MXC_PLL_DP_CONFIG_LDREQ 0x1
#define MXC_PLL_DP_OP_MFI_OFFSET 4
#define MXC_PLL_DP_OP_MFI_MASK (0xF << 4)
#define MXC_PLL_DP_OP_PDF_OFFSET 0
#define MXC_PLL_DP_OP_PDF_MASK 0xF
#define MXC_PLL_DP_MFD_OFFSET 0
#define MXC_PLL_DP_MFD_MASK 0x07FFFFFF
#define MXC_PLL_DP_MFN_OFFSET 0x0
#define MXC_PLL_DP_MFN_MASK 0x07FFFFFF
#define MXC_PLL_DP_MFN_TOGC_TOG_DIS (1 << 17)
#define MXC_PLL_DP_MFN_TOGC_TOG_EN (1 << 16)
#define MXC_PLL_DP_MFN_TOGC_CNT_OFFSET 0x0
#define MXC_PLL_DP_MFN_TOGC_CNT_MASK 0xFFFF
#define MXC_PLL_DP_DESTAT_TOG_SEL (1 << 31)
#define MXC_PLL_DP_DESTAT_MFN 0x07FFFFFF
#define MAX_DPLL_WAIT_TRIES 1000 /* 1000 * udelay(1) = 1ms */
struct clk_pllv2 {
struct clk_hw hw;
void __iomem *base;
};
static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn)
{
long mfi, mfn, mfd, pdf, ref_clk, mfn_abs;
unsigned long dbl;
s64 temp;
dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN;
pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK;
mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
mfi = (mfi <= 5) ? 5 : mfi;
mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
mfn = mfn_abs = dp_mfn & MXC_PLL_DP_MFN_MASK;
/* Sign extend to 32-bits */
if (mfn >= 0x04000000) {
mfn |= 0xFC000000;
mfn_abs = -mfn;
}
ref_clk = 2 * parent_rate;
if (dbl != 0)
ref_clk *= 2;
ref_clk /= (pdf + 1);
temp = (u64) ref_clk * mfn_abs;
do_div(temp, mfd + 1);
if (mfn < 0)
temp = -temp;
temp = (ref_clk * mfi) + temp;
return temp;
}
static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
u32 dp_op, dp_mfd, dp_mfn, dp_ctl;
void __iomem *pllbase;
struct clk_pllv2 *pll = to_clk_pllv2(hw);
pllbase = pll->base;
dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP);
dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD);
dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN);
return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn);
}
static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate,
u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn)
{
u32 reg;
long mfi, pdf, mfn, mfd = 999999;
s64 temp64;
unsigned long quad_parent_rate;
quad_parent_rate = 4 * parent_rate;
pdf = mfi = -1;
while (++pdf < 16 && mfi < 5)
mfi = rate * (pdf+1) / quad_parent_rate;
if (mfi > 15)
return -EINVAL;
pdf--;
temp64 = rate * (pdf + 1) - quad_parent_rate * mfi;
do_div(temp64, quad_parent_rate / 1000000);
mfn = (long)temp64;
reg = mfi << 4 | pdf;
*dp_op = reg;
*dp_mfd = mfd;
*dp_mfn = mfn;
return 0;
}
static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_pllv2 *pll = to_clk_pllv2(hw);
void __iomem *pllbase;
u32 dp_ctl, dp_op, dp_mfd, dp_mfn;
int ret;
pllbase = pll->base;
ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn);
if (ret)
return ret;
dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
/* use dpdck0_2 */
__raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL);
__raw_writel(dp_op, pllbase + MXC_PLL_DP_OP);
__raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD);
__raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN);
return 0;
}
static long clk_pllv2_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
u32 dp_op, dp_mfd, dp_mfn;
__clk_pllv2_set_rate(rate, *prate, &dp_op, &dp_mfd, &dp_mfn);
return __clk_pllv2_recalc_rate(*prate, MXC_PLL_DP_CTL_DPDCK0_2_EN,
dp_op, dp_mfd, dp_mfn);
}
static int clk_pllv2_prepare(struct clk_hw *hw)
{
struct clk_pllv2 *pll = to_clk_pllv2(hw);
u32 reg;
void __iomem *pllbase;
int i = 0;
pllbase = pll->base;
reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
/* Wait for lock */
do {
reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
if (reg & MXC_PLL_DP_CTL_LRF)
break;
udelay(1);
} while (++i < MAX_DPLL_WAIT_TRIES);
if (i == MAX_DPLL_WAIT_TRIES) {
pr_err("MX5: pll locking failed\n");
return -EINVAL;
}
return 0;
}
static void clk_pllv2_unprepare(struct clk_hw *hw)
{
struct clk_pllv2 *pll = to_clk_pllv2(hw);
u32 reg;
void __iomem *pllbase;
pllbase = pll->base;
reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) & ~MXC_PLL_DP_CTL_UPEN;
__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
}
struct clk_ops clk_pllv2_ops = {
.prepare = clk_pllv2_prepare,
.unprepare = clk_pllv2_unprepare,
.recalc_rate = clk_pllv2_recalc_rate,
.round_rate = clk_pllv2_round_rate,
.set_rate = clk_pllv2_set_rate,
};
struct clk *imx_clk_pllv2(const char *name, const char *parent,
void __iomem *base)
{
struct clk_pllv2 *pll;
struct clk *clk;
struct clk_init_data init;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
pll->base = base;
init.name = name;
init.ops = &clk_pllv2_ops;
init.flags = 0;
init.parent_names = &parent;
init.num_parents = 1;
pll->hw.init = &init;
clk = clk_register(NULL, &pll->hw);
if (IS_ERR(clk))
kfree(pll);
return clk;
}