clk: stm32: retrieve external oscillator frequency from DT
All current STM32F4 supported boards uses a 8MHz external oscillator.
All current STM32F7 supported boards uses a 25MHz external oscillator.
In order to introduce the new stm32f429-evaluation board which uses a
25MHz external oscillator without creating a dedicated struct
stm32_clk_info for this board, retrieve the external oscillator
frequency from DT and set pll_m accordingly to obtain 1MHz for the VCO.
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/drivers/clk/clk_stm32f.c b/drivers/clk/clk_stm32f.c
index 63116e0..ebe1ce6 100644
--- a/drivers/clk/clk_stm32f.c
+++ b/drivers/clk/clk_stm32f.c
@@ -93,10 +93,9 @@
STMMAC_CLOCK_CFG,
};
-struct stm32_clk_info stm32f4_clk_info = {
+static const struct stm32_clk_info stm32f4_clk_info = {
/* 180 MHz */
.sys_pll_psc = {
- .pll_m = 8,
.pll_n = 360,
.pll_p = 2,
.pll_q = 8,
@@ -108,10 +107,9 @@
.v2 = false,
};
-struct stm32_clk_info stm32f7_clk_info = {
+static const struct stm32_clk_info stm32f7_clk_info = {
/* 200 MHz */
.sys_pll_psc = {
- .pll_m = 25,
.pll_n = 400,
.pll_p = 2,
.pll_q = 8,
@@ -126,7 +124,8 @@
struct stm32_clk {
struct stm32_rcc_regs *base;
struct stm32_pwr_regs *pwr_regs;
- struct stm32_clk_info *info;
+ struct stm32_clk_info info;
+ unsigned long hse_rate;
};
static int configure_clocks(struct udevice *dev)
@@ -134,7 +133,7 @@
struct stm32_clk *priv = dev_get_priv(dev);
struct stm32_rcc_regs *regs = priv->base;
struct stm32_pwr_regs *pwr = priv->pwr_regs;
- struct pll_psc sys_pll_psc = priv->info->sys_pll_psc;
+ struct pll_psc *sys_pll_psc = &priv->info.sys_pll_psc;
u32 pllsaicfgr = 0;
/* Reset RCC configuration */
@@ -152,20 +151,20 @@
;
setbits_le32(®s->cfgr, ((
- sys_pll_psc.ahb_psc << RCC_CFGR_HPRE_SHIFT)
- | (sys_pll_psc.apb1_psc << RCC_CFGR_PPRE1_SHIFT)
- | (sys_pll_psc.apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
+ sys_pll_psc->ahb_psc << RCC_CFGR_HPRE_SHIFT)
+ | (sys_pll_psc->apb1_psc << RCC_CFGR_PPRE1_SHIFT)
+ | (sys_pll_psc->apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
/* Configure the main PLL */
setbits_le32(®s->pllcfgr, RCC_PLLCFGR_PLLSRC); /* pll source HSE */
clrsetbits_le32(®s->pllcfgr, RCC_PLLCFGR_PLLM_MASK,
- sys_pll_psc.pll_m << RCC_PLLCFGR_PLLM_SHIFT);
+ sys_pll_psc->pll_m << RCC_PLLCFGR_PLLM_SHIFT);
clrsetbits_le32(®s->pllcfgr, RCC_PLLCFGR_PLLN_MASK,
- sys_pll_psc.pll_n << RCC_PLLCFGR_PLLN_SHIFT);
+ sys_pll_psc->pll_n << RCC_PLLCFGR_PLLN_SHIFT);
clrsetbits_le32(®s->pllcfgr, RCC_PLLCFGR_PLLP_MASK,
- ((sys_pll_psc.pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT);
+ ((sys_pll_psc->pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT);
clrsetbits_le32(®s->pllcfgr, RCC_PLLCFGR_PLLQ_MASK,
- sys_pll_psc.pll_q << RCC_PLLCFGR_PLLQ_SHIFT);
+ sys_pll_psc->pll_q << RCC_PLLCFGR_PLLQ_SHIFT);
/* Configure the SAI PLL to get a 48 MHz source */
pllsaicfgr = RCC_PLLSAICFGR_PLLSAIR_2 | RCC_PLLSAICFGR_PLLSAIQ_4 |
@@ -178,7 +177,7 @@
while (!(readl(®s->cr) & RCC_CR_PLLRDY))
;
- if (priv->info->v2) { /*stm32f7 case */
+ if (priv->info.v2) { /*stm32f7 case */
/* select PLLSAI as 48MHz clock source */
setbits_le32(®s->dckcfgr2, RCC_DCKCFGRX_CK48MSEL);
@@ -202,7 +201,7 @@
setbits_le32(®s->apb1enr, RCC_APB1ENR_PWREN);
- if (priv->info->has_overdrive) {
+ if (priv->info.has_overdrive) {
/*
* Enable high performance mode
* System frequency up to 200 MHz
@@ -241,7 +240,7 @@
pllq = (readl(®s->pllcfgr) & RCC_PLLCFGR_PLLQ_MASK)
>> RCC_PLLCFGR_PLLQ_SHIFT;
- if (priv->info->v2) /*stm32f7 case */
+ if (priv->info.v2) /*stm32f7 case */
pllsai = readl(®s->dckcfgr2) & RCC_DCKCFGRX_CK48MSEL;
else
pllsai = readl(®s->dckcfgr) & RCC_DCKCFGRX_CK48MSEL;
@@ -253,7 +252,7 @@
>> RCC_PLLSAICFGR_PLLSAIN_SHIFT);
pllsaip = ((((readl(®s->pllsaicfgr) & RCC_PLLCFGR_PLLSAIP_MASK)
>> RCC_PLLSAICFGR_PLLSAIP_SHIFT) + 1) << 1);
- return ((CONFIG_STM32_HSE_HZ / pllm) * pllsain) / pllsaip;
+ return ((priv->hse_rate / pllm) * pllsain) / pllsaip;
}
/* PLL48CLK is selected from PLLQ */
return sysclk / pllq;
@@ -281,7 +280,7 @@
>> RCC_PLLCFGR_PLLN_SHIFT);
pllp = ((((readl(®s->pllcfgr) & RCC_PLLCFGR_PLLP_MASK)
>> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1);
- sysclk = ((CONFIG_STM32_HSE_HZ / pllm) * plln) / pllp;
+ sysclk = ((priv->hse_rate / pllm) * plln) / pllp;
} else {
return -EINVAL;
}
@@ -372,6 +371,8 @@
static int stm32_clk_probe(struct udevice *dev)
{
struct ofnode_phandle_args args;
+ struct udevice *fixed_clock_dev = NULL;
+ struct clk clk;
int err;
debug("%s\n", __func__);
@@ -387,16 +388,51 @@
switch (dev_get_driver_data(dev)) {
case STM32F4:
- priv->info = &stm32f4_clk_info;
+ memcpy(&priv->info, &stm32f4_clk_info,
+ sizeof(struct stm32_clk_info));
break;
case STM32F7:
- priv->info = &stm32f7_clk_info;
+ memcpy(&priv->info, &stm32f7_clk_info,
+ sizeof(struct stm32_clk_info));
break;
default:
return -EINVAL;
}
- if (priv->info->has_overdrive) {
+ /* retrieve HSE frequency (external oscillator) */
+ err = uclass_get_device_by_name(UCLASS_CLK, "clk-hse",
+ &fixed_clock_dev);
+
+ if (err) {
+ pr_err("Can't find fixed clock (%d)", err);
+ return err;
+ }
+
+ err = clk_request(fixed_clock_dev, &clk);
+ if (err) {
+ pr_err("Can't request %s clk (%d)", fixed_clock_dev->name,
+ err);
+ return err;
+ }
+
+ /*
+ * set pllm factor accordingly to the external oscillator
+ * frequency (HSE). For STM32F4 and STM32F7, we want VCO
+ * freq at 1MHz
+ * if input PLL frequency is 25Mhz, divide it by 25
+ */
+ clk.id = 0;
+ priv->hse_rate = clk_get_rate(&clk);
+
+ if (priv->hse_rate < 1000000) {
+ pr_err("%s: unexpected HSE clock rate = %ld \"n", __func__,
+ priv->hse_rate);
+ return -EINVAL;
+ }
+
+ priv->info.sys_pll_psc.pll_m = priv->hse_rate / 1000000;
+
+ if (priv->info.has_overdrive) {
err = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
&args);
if (err) {