in s5pv210-cpufreq.c [223:486]
static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
{
unsigned long reg;
unsigned int priv_index;
unsigned int pll_changing = 0;
unsigned int bus_speed_changing = 0;
unsigned int old_freq, new_freq;
int arm_volt, int_volt;
int ret = 0;
mutex_lock(&set_freq_lock);
if (no_cpufreq_access) {
pr_err("Denied access to %s as it is disabled temporarily\n",
__func__);
ret = -EINVAL;
goto exit;
}
old_freq = policy->cur;
new_freq = s5pv210_freq_table[index].frequency;
/* Finding current running level index */
priv_index = cpufreq_table_find_index_h(policy, old_freq, false);
arm_volt = dvs_conf[index].arm_volt;
int_volt = dvs_conf[index].int_volt;
if (new_freq > old_freq) {
ret = regulator_set_voltage(arm_regulator,
arm_volt, arm_volt_max);
if (ret)
goto exit;
ret = regulator_set_voltage(int_regulator,
int_volt, int_volt_max);
if (ret)
goto exit;
}
/* 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 = readl_relaxed(S5P_CLK_DIV2);
reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
(3 << S5P_CLKDIV2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = readl_relaxed(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 = readl_relaxed(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
(1 << S5P_CLKSRC2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC2);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 3. DMC1 refresh count for 133Mhz if (index == L4) is
* true refresh counter is already programmed in upper
* code. 0x287@83Mhz
*/
if (!bus_speed_changing)
s5pv210_set_refresh(DMC1, 133000);
/* 4. SCLKAPLL -> SCLKMPLL */
reg = readl_relaxed(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC0);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT0);
} while (reg & (0x1 << 18));
}
/* Change divider */
reg = readl_relaxed(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));
writel_relaxed(reg, S5P_CLK_DIV0);
do {
reg = readl_relaxed(S5P_CLKDIV_STAT0);
} while (reg & 0xff);
/* ARM MCS value changed */
reg = readl_relaxed(S5P_ARM_MCS_CON);
reg &= ~0x3;
if (index >= L3)
reg |= 0x3;
else
reg |= 0x1;
writel_relaxed(reg, S5P_ARM_MCS_CON);
if (pll_changing) {
/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
writel_relaxed(0x2cf, S5P_APLL_LOCK);
/*
* 6. Turn on APLL
* 6-1. Set PMS values
* 6-2. Wait until the PLL is locked
*/
if (index == L0)
writel_relaxed(APLL_VAL_1000, S5P_APLL_CON);
else
writel_relaxed(APLL_VAL_800, S5P_APLL_CON);
do {
reg = readl_relaxed(S5P_APLL_CON);
} while (!(reg & (0x1 << 29)));
/*
* 7. Change source clock from SCLKMPLL(667Mhz)
* to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
* (667/4=166)->(200/4=50)Mhz
*/
reg = readl_relaxed(S5P_CLK_SRC2);
reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
(0 << S5P_CLKSRC2_MFC_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC2);
do {
reg = readl_relaxed(S5P_CLKMUX_STAT1);
} while (reg & ((1 << 7) | (1 << 3)));
/*
* 8. Change divider for MFC and G3D
* (200/4=50)->(200/1=200)Mhz
*/
reg = readl_relaxed(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);
writel_relaxed(reg, S5P_CLK_DIV2);
/* For MFC, G3D dividing */
do {
reg = readl_relaxed(S5P_CLKDIV_STAT0);
} while (reg & ((1 << 16) | (1 << 17)));
/* 9. Change MPLL to APLL in MSYS_MUX */
reg = readl_relaxed(S5P_CLK_SRC0);
reg &= ~(S5P_CLKSRC0_MUX200_MASK);
reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
writel_relaxed(reg, S5P_CLK_SRC0);
do {
reg = readl_relaxed(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 needs to change memory bus speed, hence ONEDRAM clock
* divider and memory refresh parameter should be changed
*/
if (bus_speed_changing) {
reg = readl_relaxed(S5P_CLK_DIV6);
reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
writel_relaxed(reg, S5P_CLK_DIV6);
do {
reg = readl_relaxed(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 (new_freq < old_freq) {
regulator_set_voltage(int_regulator,
int_volt, int_volt_max);
regulator_set_voltage(arm_regulator,
arm_volt, arm_volt_max);
}
pr_debug("Perf changed[L%d]\n", index);
exit:
mutex_unlock(&set_freq_lock);
return ret;
}