/*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* CPU frequency scaling for S5PC110/S5PV210
*
* 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.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
static struct clk *cpu_clk;
static struct clk *dmc0_clk;
static struct clk *dmc1_clk;
static struct cpufreq_freqs freqs;
/* APLL M,P,S values for 1G/800Mhz */
#define APLL_VAL_1000 ((1 << 31) | (125 << 16) | (3 << 8) | 1)
#define APLL_VAL_800 ((1 << 31) | (100 << 16) | (3 << 8) | 1)
/*
* DRAM configurations to calculate refresh counter for changing
* frequency of memory.
*/
struct dram_conf {
unsigned long freq; /* HZ */
unsigned long refresh; /* DRAM refresh counter * 1000 */
};
/* DRAM configuration (DMC0 and DMC1) */
static struct dram_conf s5pv210_dram_conf[2];
enum perf_level {
L0, L1, L2, L3, L4,
};
enum s5pv210_mem_type {
LPDDR = 0x1,
LPDDR2 = 0x2,
DDR2 = 0x4,
};
enum s5pv210_dmc_port {
DMC0 = 0,
DMC1,
};
static struct cpufreq_frequency_table s5pv210_freq_table[] = {
{L0, 1000*1000},
{L1, 800*1000},
{L2, 400*1000},
{L3, 200*1000},
{L4, 100*1000},
{0, CPUFREQ_TABLE_END},
};
static u32 clkdiv_val[5][11] = {
/*
* Clock divider value for following
* { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
* HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
* ONEDRAM, MFC, G3D }
*/
/* L0 : [1000/200/100][166/83][133/66][200/200] */
{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},
/* L1 : [800/200/100][166/83][133/66][200/200] */
{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},
/* L2 : [400/200/100][166/83][133/66][200/200] */
{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
/* L3 : [200/200/100][166/83][133/66][200/200] */
{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},
/* L4 : [100/100/100][83/83][66/66][100/100] */
{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
};
/*
* This function set DRAM refresh counter
* accoriding to operating frequency of DRAM
* ch: DMC port number 0 or 1
* freq: Operating frequency of DRAM(KHz)
*/
static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
{
unsigned long tmp, tmp1;
void __iomem *reg = NULL;
if (ch == DMC0) {
reg = (S5P_VA_DMC0 + 0x30);
} else if (ch == DMC1) {
reg = (S5P_VA_DMC1 + 0x30);
} else {
printk(KERN_ERR "Cannot find DMC port\n");
return;
}
/* Find current DRAM frequency */
tmp = s5pv210_dram_conf[ch].freq;
do_div(tmp, freq);
tmp1 = s5pv210_dram_conf[ch].refresh;
do_div(tmp1, tmp);
__raw_writel(tmp1, reg);
}
int s5pv210_verify_speed(struct cpufreq_policy *policy)
{
if (policy->cpu)
return -EINVAL;
return cpufreq_frequency_table_verify(policy, s5pv210_freq_table);
}
unsigned int s5pv210_getspeed(unsigned int cpu)
{
if (cpu)
return 0;
return clk_get_rate(cpu_clk) / 1000;
}
static int s5pv210_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned long reg;
unsigned int index, priv_index;
unsigned int pll_changing = 0;
unsigned int bus_speed_changing = 0;
freqs.old = s5pv210_getspeed(0);
if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
target_freq, relation, &index))
return -EINVAL;
freqs.new = s5pv210_freq_table[index].frequency;
freqs.cpu = 0;
if (freqs.new == freqs.old)
return 0;
/* Finding current running level index */
if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
freqs.old, relation, &priv_index))
return -EINVAL;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
if (freqs.new > freqs.old) {
/* Voltage up: will be implemented */
}
/* Check if there need to change PLL */
if ((index == L0) || (priv_index == L0))
pll_changing = 1;
/* Check if there need to change System bus clock */
if ((index == L4) || (priv_index == L4))
bus_speed_changing = 1;
if (bus_speed_changing) {
/*
* Reconfigure DRAM refresh counter value for minimum
* temporary clock while changing divider.
* expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
*/
if (pll_changing)
s5pv210_set_refresh(DMC1, 83000);
else
s5pv210_set_refresh(DMC1, 100000);
s5pv210_set_refresh(DMC0, 83000);
}
/*
* APLL should be changed in this level
* APLL -> MPLL(for stable transition) -> APLL
* Some clock source's clock API are not prepared.
* Do not use clock API in below code.
*/
if (pll_changing) {
/*
* 1. Temporary Change divider for MFC and G3D
* SCLKA2M(200/1=200)->(200/4=50)Mhz
*/
reg = __raw_readl(S5P_CLK_DIV2);
reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
(3 << S5P_CLKDIV2_MFC_SHIFT);
__raw_writel(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = __raw_readl(S5P_CLKDIV_STAT0);
} while (reg & ((1 << 16) | (1 << 17)));
/*
* 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
* (200/4=50)->(667/4=166)Mhz
*/
reg = __raw_readl(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
(1 << S5P_CLKSRC2_MFC_SHIFT);
__raw_writel(reg, S5P_CLK_SRC2);
do {
reg = __raw_readl(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 3. DMC1 refresh count for 133Mhz if (index == L4) is
* true refresh counter is already programed in upper
* code. 0x287@83Mhz
*/
if (!bus_speed_changing)
s5pv210_set_refresh(DMC1, 133000);
/* 4. SCLKAPLL -> SCLKMPLL */
reg = __raw_readl(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
__raw_writel(reg, S5P_CLK_SRC0);
do {
reg = __raw_readl(S5P_CLKMUX_STAT0);
} while (reg & (0x1 << 18));
}
/* Change divider */
reg = __raw_readl(S5P_CLK_DIV0);
reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);
reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));
__raw_writel(reg, S5P_CLK_DIV0);
do {
reg = __raw_readl(S5P_CLKDIV_STAT0);
} while (reg & 0xff);
/* ARM MCS value changed */
reg = __raw_readl(S5P_ARM_MCS_CON);
reg &= ~0x3;
if (index >= L3)
reg |= 0x3;
else
reg |= 0x1;
__raw_writel(reg, S5P_ARM_MCS_CON);
if (pll_changing) {
/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
__raw_writel(0x2cf, S5P_APLL_LOCK);
/*
* 6. Turn on APLL
* 6-1. Set PMS values
* 6-2. Wait untile the PLL is locked
*/
if (index == L0)
__raw_writel(APLL_VAL_1000, S5P_APLL_CON);
else
__raw_writel(APLL_VAL_800, S5P_APLL_CON);
do {
reg = __raw_readl(S5P_APLL_CON);
} while (!(reg & (0x1 << 29)));
/*
* 7. Change souce clock from SCLKMPLL(667Mhz)
* to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
* (667/4=166)->(200/4=50)Mhz
*/
reg = __raw_readl(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
(0 << S5P_CLKSRC2_MFC_SHIFT);
__raw_writel(reg, S5P_CLK_SRC2);
do {
reg = __raw_readl(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 8. Change divider for MFC and G3D
* (200/4=50)->(200/1=200)Mhz
*/
reg = __raw_readl(S5P_CLK_DIV2);
reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
__raw_writel(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = __raw_readl(S5P_CLKDIV_STAT0);
} while (reg & ((1 << 16) | (1 << 17)));
/* 9. Change MPLL to APLL in MSYS_MUX */
reg = __raw_readl(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
__raw_writel(reg, S5P_CLK_SRC0);
do {
reg = __raw_readl(S5P_CLKMUX_STAT0);
} while (reg & (0x1 << 18));
/*
* 10. DMC1 refresh counter
* L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
* Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
*/
if (!bus_speed_changing)
s5pv210_set_refresh(DMC1, 200000);
}
/*
* L4 level need to change memory bus speed, hence onedram clock divier
* and memory refresh parameter should be changed
*/
if (bus_speed_changing) {
reg = __raw_readl(S5P_CLK_DIV6);
reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
__raw_writel(reg, S5P_CLK_DIV6);
do {
reg = __raw_readl(S5P_CLKDIV_STAT1);
} while (reg & (1 << 15));
/* Reconfigure DRAM refresh counter value */
if (index != L4) {
/*
* DMC0 : 166Mhz
* DMC1 : 200Mhz
*/
s5pv210_set_refresh(DMC0, 166000);
s5pv210_set_refresh(DMC1, 200000);
} else {
/*
* DMC0 : 83Mhz
* DMC1 : 100Mhz
*/
s5pv210_set_refresh(DMC0, 83000);
s5pv210_set_refresh(DMC1, 100000);
}
}
if (freqs.new < freqs.old) {
/* Voltage down: will be implemented */
}
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
printk(KERN_DEBUG "Perf changed[L%d]\n", index);
return 0;
}
#ifdef CONFIG_PM
static int s5pv210_cpufreq_suspend(struct cpufreq_policy *policy)
{
return 0;
}
static int s5pv210_cpufreq_resume(struct cpufreq_policy *policy)
{
return 0;
}
#endif
static int check_mem_type(void __iomem *dmc_reg)
{
unsigned long val;
val = __raw_readl(dmc_reg + 0x4);
val = (val & (0xf << 8));
return val >> 8;
}
static int __init s5pv210_cpu_init(struct cpufreq_policy *policy)
{
unsigned long mem_type;
int ret;
cpu_clk = clk_get(NULL, "armclk");
if (IS_ERR(cpu_clk))
return PTR_ERR(cpu_clk);
dmc0_clk = clk_get(NULL, "sclk_dmc0");
if (IS_ERR(dmc0_clk)) {
ret = PTR_ERR(dmc0_clk);
goto out_dmc0;
}
dmc1_clk = clk_get(NULL, "hclk_msys");
if (IS_ERR(dmc1_clk)) {
ret = PTR_ERR(dmc1_clk);
goto out_dmc1;
}
if (policy->cpu != 0) {
ret = -EINVAL;
goto out_dmc1;
}
/*
* check_mem_type : This driver only support LPDDR & LPDDR2.
* other memory type is not supported.
*/
mem_type = check_mem_type(S5P_VA_DMC0);
if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
printk(KERN_ERR "CPUFreq doesn't support this memory type\n");
ret = -EINVAL;
goto out_dmc1;
}
/* Find current refresh counter and frequency each DMC */
s5pv210_dram_conf[0].refresh = (__raw_readl(S5P_VA_DMC0 + 0x30) * 1000);
s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);
s5pv210_dram_conf[1].refresh = (__raw_readl(S5P_VA_DMC1 + 0x30) * 1000);
s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);
policy->cur = policy->min = policy->max = s5pv210_getspeed(0);
cpufreq_frequency_table_get_attr(s5pv210_freq_table, policy->cpu);
policy->cpuinfo.transition_latency = 40000;
return cpufreq_frequency_table_cpuinfo(policy, s5pv210_freq_table);
out_dmc1:
clk_put(dmc0_clk);
out_dmc0:
clk_put(cpu_clk);
return ret;
}
static struct cpufreq_driver s5pv210_driver = {
.flags = CPUFREQ_STICKY,
.verify = s5pv210_verify_speed,
.target = s5pv210_target,
.get = s5pv210_getspeed,
.init = s5pv210_cpu_init,
.name = "s5pv210",
#ifdef CONFIG_PM
.suspend = s5pv210_cpufreq_suspend,
.resume = s5pv210_cpufreq_resume,
#endif
};
static int __init s5pv210_cpufreq_init(void)
{
return cpufreq_register_driver(&s5pv210_driver);
}
late_initcall(s5pv210_cpufreq_init);
