From e44cdff05145b84293e3f424daa17e4f3ce0109c Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Thu, 19 Nov 2020 17:45:09 +0100 Subject: clk: samsung: Allow compile testing of Exynos, S3C64xx and S5Pv210 So far all Exynos, S3C64xx and S5Pv210 clock units were selected by respective SOC/ARCH Kconfig option. On a kernel built for selected SoCs, this allowed to build only limited set of matching clock drivers. However compile testing was not possible in such case as Makefile object depends on SOC/ARCH option. Add separate Kconfig options for each of them to be able to compile test. Link: https://lore.kernel.org/r/20201119164509.754851-1-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski Acked-by: Chanwoo Choi Signed-off-by: Sylwester Nawrocki --- drivers/clk/samsung/Kconfig | 67 ++++++++++++++++++++++++++++++++++++++++++-- drivers/clk/samsung/Makefile | 22 +++++++-------- 2 files changed, 76 insertions(+), 13 deletions(-) (limited to 'drivers/clk/samsung') diff --git a/drivers/clk/samsung/Kconfig b/drivers/clk/samsung/Kconfig index 57d4b3f20417..9323fcfac6cc 100644 --- a/drivers/clk/samsung/Kconfig +++ b/drivers/clk/samsung/Kconfig @@ -2,10 +2,73 @@ # Recent Exynos platforms should just select COMMON_CLK_SAMSUNG: config COMMON_CLK_SAMSUNG bool "Samsung Exynos clock controller support" if COMPILE_TEST - # Clocks on ARM64 SoCs (e.g. Exynos5433, Exynos7) are chosen by - # EXYNOS_ARM64_COMMON_CLK to avoid building them on ARMv7: + select S3C64XX_COMMON_CLK if ARM && ARCH_S3C64XX + select S5PV210_COMMON_CLK if ARM && ARCH_S5PV210 + select EXYNOS_3250_COMMON_CLK if ARM && SOC_EXYNOS3250 + select EXYNOS_4_COMMON_CLK if ARM && ARCH_EXYNOS4 + select EXYNOS_5250_COMMON_CLK if ARM && SOC_EXYNOS5250 + select EXYNOS_5260_COMMON_CLK if ARM && SOC_EXYNOS5260 + select EXYNOS_5410_COMMON_CLK if ARM && SOC_EXYNOS5410 + select EXYNOS_5420_COMMON_CLK if ARM && SOC_EXYNOS5420 select EXYNOS_ARM64_COMMON_CLK if ARM64 && ARCH_EXYNOS +config S3C64XX_COMMON_CLK + bool "Samsung S3C64xx clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung S3C64xx SoCs. + Choose Y here only if you build for this SoC. + +config S5PV210_COMMON_CLK + bool "Samsung S5Pv210 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung S5Pv210 SoCs. + Choose Y here only if you build for this SoC. + +config EXYNOS_3250_COMMON_CLK + bool "Samsung Exynos3250 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos3250 SoCs. Choose Y here only if you build for this SoC. + +config EXYNOS_4_COMMON_CLK + bool "Samsung Exynos4 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos4212 and Exynos4412 SoCs. Choose Y here only if you build for + this SoC. + +config EXYNOS_5250_COMMON_CLK + bool "Samsung Exynos5250 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos5250 SoCs. Choose Y here only if you build for this SoC. + +config EXYNOS_5260_COMMON_CLK + bool "Samsung Exynos5260 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos5260 SoCs. Choose Y here only if you build for this SoC. + +config EXYNOS_5410_COMMON_CLK + bool "Samsung Exynos5410 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos5410 SoCs. Choose Y here only if you build for this SoC. + +config EXYNOS_5420_COMMON_CLK + bool "Samsung Exynos5420 clock controller support" if COMPILE_TEST + depends on COMMON_CLK_SAMSUNG + help + Support for the clock controller present on the Samsung + Exynos5420 SoCs. Choose Y here only if you build for this SoC. + config EXYNOS_ARM64_COMMON_CLK bool "Samsung Exynos ARMv8-family clock controller support" if COMPILE_TEST depends on COMMON_CLK_SAMSUNG diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index 1a4e6b787978..bb1433f11c88 100644 --- a/drivers/clk/samsung/Makefile +++ b/drivers/clk/samsung/Makefile @@ -4,15 +4,15 @@ # obj-$(CONFIG_COMMON_CLK) += clk.o clk-pll.o clk-cpu.o -obj-$(CONFIG_SOC_EXYNOS3250) += clk-exynos3250.o -obj-$(CONFIG_ARCH_EXYNOS4) += clk-exynos4.o -obj-$(CONFIG_ARCH_EXYNOS4) += clk-exynos4412-isp.o -obj-$(CONFIG_SOC_EXYNOS5250) += clk-exynos5250.o -obj-$(CONFIG_SOC_EXYNOS5250) += clk-exynos5-subcmu.o -obj-$(CONFIG_SOC_EXYNOS5260) += clk-exynos5260.o -obj-$(CONFIG_SOC_EXYNOS5410) += clk-exynos5410.o -obj-$(CONFIG_SOC_EXYNOS5420) += clk-exynos5420.o -obj-$(CONFIG_SOC_EXYNOS5420) += clk-exynos5-subcmu.o +obj-$(CONFIG_EXYNOS_3250_COMMON_CLK) += clk-exynos3250.o +obj-$(CONFIG_EXYNOS_4_COMMON_CLK) += clk-exynos4.o +obj-$(CONFIG_EXYNOS_4_COMMON_CLK) += clk-exynos4412-isp.o +obj-$(CONFIG_EXYNOS_5250_COMMON_CLK) += clk-exynos5250.o +obj-$(CONFIG_EXYNOS_5250_COMMON_CLK) += clk-exynos5-subcmu.o +obj-$(CONFIG_EXYNOS_5260_COMMON_CLK) += clk-exynos5260.o +obj-$(CONFIG_EXYNOS_5410_COMMON_CLK) += clk-exynos5410.o +obj-$(CONFIG_EXYNOS_5420_COMMON_CLK) += clk-exynos5420.o +obj-$(CONFIG_EXYNOS_5420_COMMON_CLK) += clk-exynos5-subcmu.o obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK) += clk-exynos5433.o obj-$(CONFIG_EXYNOS_AUDSS_CLK_CON) += clk-exynos-audss.o obj-$(CONFIG_ARCH_EXYNOS) += clk-exynos-clkout.o @@ -21,5 +21,5 @@ obj-$(CONFIG_S3C2410_COMMON_CLK)+= clk-s3c2410.o obj-$(CONFIG_S3C2410_COMMON_DCLK)+= clk-s3c2410-dclk.o obj-$(CONFIG_S3C2412_COMMON_CLK)+= clk-s3c2412.o obj-$(CONFIG_S3C2443_COMMON_CLK)+= clk-s3c2443.o -obj-$(CONFIG_ARCH_S3C64XX) += clk-s3c64xx.o -obj-$(CONFIG_ARCH_S5PV210) += clk-s5pv210.o clk-s5pv210-audss.o +obj-$(CONFIG_S3C64XX_COMMON_CLK) += clk-s3c64xx.o +obj-$(CONFIG_S5PV210_COMMON_CLK) += clk-s5pv210.o clk-s5pv210-audss.o -- cgit v1.2.3 From 44a9e78f9242872c889f176782777fa2ed535650 Mon Sep 17 00:00:00 2001 From: Sylwester Nawrocki Date: Fri, 20 Nov 2020 16:57:31 +0100 Subject: clk: samsung: Prevent potential endless loop in the PLL ops The PLL status polling loops in the set_rate callbacks of some PLLs have no timeout detection and may become endless loops when something goes wrong with the PLL. For some PLLs there is already the ktime API based timeout detection, but it will not work in all conditions when .set_rate gets called. In particular, before the clocksource is initialized or when the timekeeping is suspended. This patch adds a common helper with the PLL status bit polling and timeout detection. For conditions where the timekeeping API should not be used a simple readl_relaxed/cpu_relax() busy loop is added with the iterations limit derived from measurements of readl_relaxed() execution time for various PLL types and Exynos SoCs variants. Actual PLL lock time depends on the P divider value, the VCO frequency and a constant PLL type specific LOCK_FACTOR and can be calculated as lock_time = Pdiv * LOCK_FACTOR / VCO_freq For the ktime API use cases a common timeout value of 20 ms is applied for all the PLLs with an assumption that maximum possible value of Pdiv is 64, maximum possible LOCK_FACTOR value is 3000 and minimum VCO frequency is 24 MHz. Link: https://lore.kernel.org/r/20201120155731.26898-1-s.nawrocki@samsung.com Reviewed-by: Krzysztof Kozlowski Signed-off-by: Sylwester Nawrocki --- drivers/clk/samsung/clk-pll.c | 147 ++++++++++++++++++++---------------------- 1 file changed, 71 insertions(+), 76 deletions(-) (limited to 'drivers/clk/samsung') diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c index ac70ad785d8e..5873a9354b50 100644 --- a/drivers/clk/samsung/clk-pll.c +++ b/drivers/clk/samsung/clk-pll.c @@ -8,14 +8,17 @@ #include #include +#include #include #include +#include #include #include #include "clk.h" #include "clk-pll.h" -#define PLL_TIMEOUT_MS 10 +#define PLL_TIMEOUT_US 20000U +#define PLL_TIMEOUT_LOOPS 1000000U struct samsung_clk_pll { struct clk_hw hw; @@ -63,6 +66,53 @@ static long samsung_pll_round_rate(struct clk_hw *hw, return rate_table[i - 1].rate; } +static bool pll_early_timeout = true; + +static int __init samsung_pll_disable_early_timeout(void) +{ + pll_early_timeout = false; + return 0; +} +arch_initcall(samsung_pll_disable_early_timeout); + +/* Wait until the PLL is locked */ +static int samsung_pll_lock_wait(struct samsung_clk_pll *pll, + unsigned int reg_mask) +{ + int i, ret; + u32 val; + + /* + * This function might be called when the timekeeping API can't be used + * to detect timeouts. One situation is when the clocksource is not yet + * initialized, another when the timekeeping is suspended. udelay() also + * cannot be used when the clocksource is not running on arm64, since + * the current timer is used as cycle counter. So a simple busy loop + * is used here in that special cases. The limit of iterations has been + * derived from experimental measurements of various PLLs on multiple + * Exynos SoC variants. Single register read time was usually in range + * 0.4...1.5 us, never less than 0.4 us. + */ + if (pll_early_timeout || timekeeping_suspended) { + i = PLL_TIMEOUT_LOOPS; + while (i-- > 0) { + if (readl_relaxed(pll->con_reg) & reg_mask) + return 0; + + cpu_relax(); + } + ret = -ETIMEDOUT; + } else { + ret = readl_relaxed_poll_timeout_atomic(pll->con_reg, val, + val & reg_mask, 0, PLL_TIMEOUT_US); + } + + if (ret < 0) + pr_err("Could not lock PLL %s\n", clk_hw_get_name(&pll->hw)); + + return ret; +} + static int samsung_pll3xxx_enable(struct clk_hw *hw) { struct samsung_clk_pll *pll = to_clk_pll(hw); @@ -72,13 +122,7 @@ static int samsung_pll3xxx_enable(struct clk_hw *hw) tmp |= BIT(pll->enable_offs); writel_relaxed(tmp, pll->con_reg); - /* wait lock time */ - do { - cpu_relax(); - tmp = readl_relaxed(pll->con_reg); - } while (!(tmp & BIT(pll->lock_offs))); - - return 0; + return samsung_pll_lock_wait(pll, BIT(pll->lock_offs)); } static void samsung_pll3xxx_disable(struct clk_hw *hw) @@ -240,13 +284,10 @@ static int samsung_pll35xx_set_rate(struct clk_hw *hw, unsigned long drate, (rate->sdiv << PLL35XX_SDIV_SHIFT); writel_relaxed(tmp, pll->con_reg); - /* Wait until the PLL is locked if it is enabled. */ - if (tmp & BIT(pll->enable_offs)) { - do { - cpu_relax(); - tmp = readl_relaxed(pll->con_reg); - } while (!(tmp & BIT(pll->lock_offs))); - } + /* Wait for PLL lock if the PLL is enabled */ + if (tmp & BIT(pll->enable_offs)) + return samsung_pll_lock_wait(pll, BIT(pll->lock_offs)); + return 0; } @@ -318,7 +359,7 @@ static int samsung_pll36xx_set_rate(struct clk_hw *hw, unsigned long drate, unsigned long parent_rate) { struct samsung_clk_pll *pll = to_clk_pll(hw); - u32 tmp, pll_con0, pll_con1; + u32 pll_con0, pll_con1; const struct samsung_pll_rate_table *rate; rate = samsung_get_pll_settings(pll, drate); @@ -356,13 +397,8 @@ static int samsung_pll36xx_set_rate(struct clk_hw *hw, unsigned long drate, pll_con1 |= rate->kdiv << PLL36XX_KDIV_SHIFT; writel_relaxed(pll_con1, pll->con_reg + 4); - /* wait_lock_time */ - if (pll_con0 & BIT(pll->enable_offs)) { - do { - cpu_relax(); - tmp = readl_relaxed(pll->con_reg); - } while (!(tmp & BIT(pll->lock_offs))); - } + if (pll_con0 & BIT(pll->enable_offs)) + return samsung_pll_lock_wait(pll, BIT(pll->lock_offs)); return 0; } @@ -437,7 +473,6 @@ static int samsung_pll45xx_set_rate(struct clk_hw *hw, unsigned long drate, struct samsung_clk_pll *pll = to_clk_pll(hw); const struct samsung_pll_rate_table *rate; u32 con0, con1; - ktime_t start; /* Get required rate settings from table */ rate = samsung_get_pll_settings(pll, drate); @@ -488,21 +523,8 @@ static int samsung_pll45xx_set_rate(struct clk_hw *hw, unsigned long drate, writel_relaxed(con1, pll->con_reg + 0x4); writel_relaxed(con0, pll->con_reg); - /* Wait for locking. */ - start = ktime_get(); - while (!(readl_relaxed(pll->con_reg) & PLL45XX_LOCKED)) { - ktime_t delta = ktime_sub(ktime_get(), start); - - if (ktime_to_ms(delta) > PLL_TIMEOUT_MS) { - pr_err("%s: could not lock PLL %s\n", - __func__, clk_hw_get_name(hw)); - return -EFAULT; - } - - cpu_relax(); - } - - return 0; + /* Wait for PLL lock */ + return samsung_pll_lock_wait(pll, PLL45XX_LOCKED); } static const struct clk_ops samsung_pll45xx_clk_ops = { @@ -588,7 +610,6 @@ static int samsung_pll46xx_set_rate(struct clk_hw *hw, unsigned long drate, struct samsung_clk_pll *pll = to_clk_pll(hw); const struct samsung_pll_rate_table *rate; u32 con0, con1, lock; - ktime_t start; /* Get required rate settings from table */ rate = samsung_get_pll_settings(pll, drate); @@ -647,21 +668,8 @@ static int samsung_pll46xx_set_rate(struct clk_hw *hw, unsigned long drate, writel_relaxed(con0, pll->con_reg); writel_relaxed(con1, pll->con_reg + 0x4); - /* Wait for locking. */ - start = ktime_get(); - while (!(readl_relaxed(pll->con_reg) & PLL46XX_LOCKED)) { - ktime_t delta = ktime_sub(ktime_get(), start); - - if (ktime_to_ms(delta) > PLL_TIMEOUT_MS) { - pr_err("%s: could not lock PLL %s\n", - __func__, clk_hw_get_name(hw)); - return -EFAULT; - } - - cpu_relax(); - } - - return 0; + /* Wait for PLL lock */ + return samsung_pll_lock_wait(pll, PLL46XX_LOCKED); } static const struct clk_ops samsung_pll46xx_clk_ops = { @@ -1035,14 +1043,9 @@ static int samsung_pll2550xx_set_rate(struct clk_hw *hw, unsigned long drate, (rate->sdiv << PLL2550XX_S_SHIFT); writel_relaxed(tmp, pll->con_reg); - /* wait_lock_time */ - do { - cpu_relax(); - tmp = readl_relaxed(pll->con_reg); - } while (!(tmp & (PLL2550XX_LOCK_STAT_MASK - << PLL2550XX_LOCK_STAT_SHIFT))); - - return 0; + /* Wait for PLL lock */ + return samsung_pll_lock_wait(pll, + PLL2550XX_LOCK_STAT_MASK << PLL2550XX_LOCK_STAT_SHIFT); } static const struct clk_ops samsung_pll2550xx_clk_ops = { @@ -1132,13 +1135,9 @@ static int samsung_pll2650x_set_rate(struct clk_hw *hw, unsigned long drate, con1 |= ((rate->kdiv & PLL2650X_K_MASK) << PLL2650X_K_SHIFT); writel_relaxed(con1, pll->con_reg + 4); - do { - cpu_relax(); - con0 = readl_relaxed(pll->con_reg); - } while (!(con0 & (PLL2650X_LOCK_STAT_MASK - << PLL2650X_LOCK_STAT_SHIFT))); - - return 0; + /* Wait for PLL lock */ + return samsung_pll_lock_wait(pll, + PLL2650X_LOCK_STAT_MASK << PLL2650X_LOCK_STAT_SHIFT); } static const struct clk_ops samsung_pll2650x_clk_ops = { @@ -1196,7 +1195,7 @@ static int samsung_pll2650xx_set_rate(struct clk_hw *hw, unsigned long drate, unsigned long parent_rate) { struct samsung_clk_pll *pll = to_clk_pll(hw); - u32 tmp, pll_con0, pll_con2; + u32 pll_con0, pll_con2; const struct samsung_pll_rate_table *rate; rate = samsung_get_pll_settings(pll, drate); @@ -1229,11 +1228,7 @@ static int samsung_pll2650xx_set_rate(struct clk_hw *hw, unsigned long drate, writel_relaxed(pll_con0, pll->con_reg); writel_relaxed(pll_con2, pll->con_reg + 8); - do { - tmp = readl_relaxed(pll->con_reg); - } while (!(tmp & (0x1 << PLL2650XX_PLL_LOCKTIME_SHIFT))); - - return 0; + return samsung_pll_lock_wait(pll, 0x1 << PLL2650XX_PLL_LOCKTIME_SHIFT); } static const struct clk_ops samsung_pll2650xx_clk_ops = { -- cgit v1.2.3