From cb97ff9d3d0d4f9c6ff5a09878f0946a678430b2 Mon Sep 17 00:00:00 2001 From: Patrice Chotard Date: Thu, 18 Jan 2018 13:39:30 +0100 Subject: [PATCH] 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 --- drivers/clk/clk_stm32f.c | 78 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 57 insertions(+), 21 deletions(-) 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 @@ enum periph_clock { 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 @@ struct stm32_clk_info stm32f4_clk_info = { .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_info stm32f7_clk_info = { 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 @@ static int configure_clocks(struct udevice *dev) 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 @@ static int configure_clocks(struct udevice *dev) ; 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 @@ static int configure_clocks(struct udevice *dev) 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 @@ static int configure_clocks(struct udevice *dev) 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 @@ static unsigned long stm32_clk_pll48clk_rate(struct stm32_clk *priv, 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 @@ static unsigned long stm32_clk_pll48clk_rate(struct stm32_clk *priv, >> 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 @@ static unsigned long stm32_clk_get_rate(struct clk *clk) >> 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 @@ void clock_setup(int peripheral) 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 @@ static int stm32_clk_probe(struct udevice *dev) 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) { -- 2.7.4