From 861adc44d2905469f2b9a2e053f3dc64728091ee Mon Sep 17 00:00:00 2001 From: Gabriel Fernandez Date: Fri, 21 Oct 2016 11:23:28 +0200 Subject: [PATCH] clk: stm32f4: Add LSI & LSE clocks This patch introduces the support of the LSI & LSE clocks. The clock drivers needs to disable the power domain write protection using syscon/regmap to enable these clocks. Signed-off-by: Gabriel Fernandez Signed-off-by: Stephen Boyd --- drivers/clk/clk-stm32f4.c | 131 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 126 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c index 02d681008401..6427e0fdde59 100644 --- a/drivers/clk/clk-stm32f4.c +++ b/drivers/clk/clk-stm32f4.c @@ -19,10 +19,14 @@ #include #include #include +#include +#include #include #include #include #include +#include +#include #define STM32F4_RCC_PLLCFGR 0x04 #define STM32F4_RCC_CFGR 0x08 @@ -31,6 +35,8 @@ #define STM32F4_RCC_AHB3ENR 0x38 #define STM32F4_RCC_APB1ENR 0x40 #define STM32F4_RCC_APB2ENR 0x44 +#define STM32F4_RCC_BDCR 0x70 +#define STM32F4_RCC_CSR 0x74 struct stm32f4_gate_data { u8 offset; @@ -120,13 +126,12 @@ static const struct stm32f4_gate_data stm32f4_gates[] __initconst = { { STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" }, }; +enum { SYSTICK, FCLK, CLK_LSI, CLK_LSE, END_PRIMARY_CLK }; /* * MAX_CLKS is the maximum value in the enumeration below plus the combined * hweight of stm32f42xx_gate_map (plus one). */ -#define MAX_CLKS 74 - -enum { SYSTICK, FCLK }; +#define MAX_CLKS (71 + END_PRIMARY_CLK + 1) /* * This bitmask tells us which bit offsets (0..192) on STM32F4[23]xxx @@ -140,6 +145,8 @@ static struct clk_hw *clks[MAX_CLKS]; static DEFINE_SPINLOCK(stm32f4_clk_lock); static void __iomem *base; +static struct regmap *pdrm; + /* * "Multiplier" device for APBx clocks. * @@ -259,7 +266,7 @@ static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary) u64 table[ARRAY_SIZE(stm32f42xx_gate_map)]; if (primary == 1) { - if (WARN_ON(secondary > FCLK)) + if (WARN_ON(secondary >= END_PRIMARY_CLK)) return -EINVAL; return secondary; } @@ -276,7 +283,7 @@ static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary) table[BIT_ULL_WORD(secondary)] &= GENMASK_ULL(secondary % BITS_PER_LONG_LONG, 0); - return FCLK + hweight64(table[0]) + + return END_PRIMARY_CLK - 1 + hweight64(table[0]) + (BIT_ULL_WORD(secondary) >= 1 ? hweight64(table[1]) : 0) + (BIT_ULL_WORD(secondary) >= 2 ? hweight64(table[2]) : 0); } @@ -292,6 +299,98 @@ stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data) return clks[i]; } +#define to_rgclk(_rgate) container_of(_rgate, struct stm32_rgate, gate) + +static inline void disable_power_domain_write_protection(void) +{ + if (pdrm) + regmap_update_bits(pdrm, 0x00, (1 << 8), (1 << 8)); +} + +static inline void enable_power_domain_write_protection(void) +{ + if (pdrm) + regmap_update_bits(pdrm, 0x00, (1 << 8), (0 << 8)); +} + +struct stm32_rgate { + struct clk_gate gate; + u8 bit_rdy_idx; +}; + +#define RTC_TIMEOUT 1000000 + +static int rgclk_enable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + struct stm32_rgate *rgate = to_rgclk(gate); + u32 reg; + int ret; + + disable_power_domain_write_protection(); + + clk_gate_ops.enable(hw); + + ret = readl_relaxed_poll_timeout_atomic(gate->reg, reg, + reg & rgate->bit_rdy_idx, 1000, RTC_TIMEOUT); + + enable_power_domain_write_protection(); + return ret; +} + +static void rgclk_disable(struct clk_hw *hw) +{ + clk_gate_ops.disable(hw); +} + +static int rgclk_is_enabled(struct clk_hw *hw) +{ + return clk_gate_ops.is_enabled(hw); +} + +static const struct clk_ops rgclk_ops = { + .enable = rgclk_enable, + .disable = rgclk_disable, + .is_enabled = rgclk_is_enabled, +}; + +static struct clk_hw *clk_register_rgate(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 bit_idx, u8 bit_rdy_idx, + u8 clk_gate_flags, spinlock_t *lock) +{ + struct stm32_rgate *rgate; + struct clk_init_data init = { NULL }; + struct clk_hw *hw; + int ret; + + rgate = kzalloc(sizeof(*rgate), GFP_KERNEL); + if (!rgate) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &rgclk_ops; + init.flags = flags; + init.parent_names = &parent_name; + init.num_parents = 1; + + rgate->bit_rdy_idx = bit_rdy_idx; + + rgate->gate.lock = lock; + rgate->gate.reg = reg; + rgate->gate.bit_idx = bit_idx; + rgate->gate.hw.init = &init; + + hw = &rgate->gate.hw; + ret = clk_hw_register(dev, hw); + if (ret) { + kfree(rgate); + hw = ERR_PTR(ret); + } + + return hw; +} + static const char *sys_parents[] __initdata = { "hsi", NULL, "pll" }; static const struct clk_div_table ahb_div_table[] = { @@ -319,6 +418,12 @@ static void __init stm32f4_rcc_init(struct device_node *np) return; } + pdrm = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); + if (IS_ERR(pdrm)) { + pdrm = NULL; + pr_warn("%s: Unable to get syscfg\n", __func__); + } + hse_clk = of_clk_get_parent_name(np, 0); clk_register_fixed_rate_with_accuracy(NULL, "hsi", NULL, 0, @@ -371,6 +476,22 @@ static void __init stm32f4_rcc_init(struct device_node *np) } } + clks[CLK_LSI] = clk_register_rgate(NULL, "lsi", "clk-lsi", 0, + base + STM32F4_RCC_CSR, 0, 2, 0, &stm32f4_clk_lock); + + if (IS_ERR(clks[CLK_LSI])) { + pr_err("Unable to register lsi clock\n"); + goto fail; + } + + clks[CLK_LSE] = clk_register_rgate(NULL, "lse", "clk-lse", 0, + base + STM32F4_RCC_BDCR, 0, 2, 0, &stm32f4_clk_lock); + + if (IS_ERR(clks[CLK_LSE])) { + pr_err("Unable to register lse clock\n"); + goto fail; + } + of_clk_add_hw_provider(np, stm32f4_rcc_lookup_clk, NULL); return; fail: -- 2.20.1