diff options
Diffstat (limited to 'arch/arm/mach-davinci/da850.c')
| -rw-r--r-- | arch/arm/mach-davinci/da850.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c index a62863c57459..49dcc71168c7 100644 --- a/arch/arm/mach-davinci/da850.c +++ b/arch/arm/mach-davinci/da850.c @@ -15,6 +15,7 @@ #include <linux/init.h> #include <linux/clk.h> #include <linux/platform_device.h> +#include <linux/cpufreq.h> #include <asm/mach/map.h> @@ -26,6 +27,7 @@ #include <mach/common.h> #include <mach/time.h> #include <mach/da8xx.h> +#include <mach/cpufreq.h> #include "clock.h" #include "mux.h" @@ -40,6 +42,11 @@ #define DA850_REF_FREQ 24000000 #define CFGCHIP3_ASYNC3_CLKSRC BIT(4) +#define CFGCHIP0_PLL_MASTER_LOCK BIT(4) + +static int da850_set_armrate(struct clk *clk, unsigned long rate); +static int da850_round_armrate(struct clk *clk, unsigned long rate); +static int da850_set_pll0rate(struct clk *clk, unsigned long armrate); static struct pll_data pll0_data = { .num = 1, @@ -57,6 +64,7 @@ static struct clk pll0_clk = { .parent = &ref_clk, .pll_data = &pll0_data, .flags = CLK_PLL, + .set_rate = da850_set_pll0rate, }; static struct clk pll0_aux_clk = { @@ -283,6 +291,8 @@ static struct clk arm_clk = { .parent = &pll0_sysclk6, .lpsc = DA8XX_LPSC0_ARM, .flags = ALWAYS_ENABLED, + .set_rate = da850_set_armrate, + .round_rate = da850_round_armrate, }; static struct clk rmii_clk = { @@ -820,6 +830,149 @@ static void da850_set_async3_src(int pllnum) __raw_writel(v, DA8XX_SYSCFG_VIRT(DA8XX_CFGCHIP3_REG)); } +#ifdef CONFIG_CPU_FREQ +/* + * Notes: + * According to the TRM, minimum PLLM results in maximum power savings. + * The OPP definitions below should keep the PLLM as low as possible. + * + * The output of the PLLM must be between 400 to 600 MHz. + * This rules out prediv of anything but divide-by-one for 24Mhz OSC input. + */ +struct da850_opp { + unsigned int freq; /* in KHz */ + unsigned int prediv; + unsigned int mult; + unsigned int postdiv; +}; + +static const struct da850_opp da850_opp_300 = { + .freq = 300000, + .prediv = 1, + .mult = 25, + .postdiv = 2, +}; + +static const struct da850_opp da850_opp_200 = { + .freq = 200000, + .prediv = 1, + .mult = 25, + .postdiv = 3, +}; + +static const struct da850_opp da850_opp_96 = { + .freq = 96000, + .prediv = 1, + .mult = 20, + .postdiv = 5, +}; + +#define OPP(freq) \ + { \ + .index = (unsigned int) &da850_opp_##freq, \ + .frequency = freq * 1000, \ + } + +static struct cpufreq_frequency_table da850_freq_table[] = { + OPP(300), + OPP(200), + OPP(96), + { + .index = 0, + .frequency = CPUFREQ_TABLE_END, + }, +}; + +static struct davinci_cpufreq_config cpufreq_info = { + .freq_table = &da850_freq_table[0], +}; + +static struct platform_device da850_cpufreq_device = { + .name = "cpufreq-davinci", + .dev = { + .platform_data = &cpufreq_info, + }, +}; + +int __init da850_register_cpufreq(void) +{ + return platform_device_register(&da850_cpufreq_device); +} + +static int da850_round_armrate(struct clk *clk, unsigned long rate) +{ + int i, ret = 0, diff; + unsigned int best = (unsigned int) -1; + + rate /= 1000; /* convert to kHz */ + + for (i = 0; da850_freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { + diff = da850_freq_table[i].frequency - rate; + if (diff < 0) + diff = -diff; + + if (diff < best) { + best = diff; + ret = da850_freq_table[i].frequency; + } + } + + return ret * 1000; +} + +static int da850_set_armrate(struct clk *clk, unsigned long index) +{ + struct clk *pllclk = &pll0_clk; + + return clk_set_rate(pllclk, index); +} + +static int da850_set_pll0rate(struct clk *clk, unsigned long index) +{ + unsigned int prediv, mult, postdiv; + struct da850_opp *opp; + struct pll_data *pll = clk->pll_data; + unsigned int v; + int ret; + + opp = (struct da850_opp *) da850_freq_table[index].index; + prediv = opp->prediv; + mult = opp->mult; + postdiv = opp->postdiv; + + /* Unlock writing to PLL registers */ + v = __raw_readl(DA8XX_SYSCFG_VIRT(DA8XX_CFGCHIP0_REG)); + v &= ~CFGCHIP0_PLL_MASTER_LOCK; + __raw_writel(v, DA8XX_SYSCFG_VIRT(DA8XX_CFGCHIP0_REG)); + + ret = davinci_set_pllrate(pll, prediv, mult, postdiv); + if (WARN_ON(ret)) + return ret; + + return 0; +} +#else +int __init da850_register_cpufreq(void) +{ + return 0; +} + +static int da850_set_armrate(struct clk *clk, unsigned long rate) +{ + return -EINVAL; +} + +static int da850_set_pll0rate(struct clk *clk, unsigned long armrate) +{ + return -EINVAL; +} + +static int da850_round_armrate(struct clk *clk, unsigned long rate) +{ + return clk->rate; +} +#endif + static struct davinci_soc_info davinci_soc_info_da850 = { .io_desc = da850_io_desc, .io_desc_num = ARRAY_SIZE(da850_io_desc), |
