diff options
Diffstat (limited to 'arch/arm/mach-s5pv210/cpufreq.c')
| -rw-r--r-- | arch/arm/mach-s5pv210/cpufreq.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/arch/arm/mach-s5pv210/cpufreq.c b/arch/arm/mach-s5pv210/cpufreq.c new file mode 100644 index 000000000000..a6f22920a2c2 --- /dev/null +++ b/arch/arm/mach-s5pv210/cpufreq.c @@ -0,0 +1,484 @@ +/* linux/arch/arm/mach-s5pv210/cpufreq.c + * + * 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"); + + /* 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, + pm_message_t pmsg) +{ + 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; + + 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)) { + clk_put(cpu_clk); + return PTR_ERR(dmc0_clk); + } + + dmc1_clk = clk_get(NULL, "hclk_msys"); + if (IS_ERR(dmc1_clk)) { + clk_put(dmc0_clk); + clk_put(cpu_clk); + return PTR_ERR(dmc1_clk); + } + + if (policy->cpu != 0) + return -EINVAL; + + /* + * 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"); + return -EINVAL; + } + + /* 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); +} + +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); |