From: Gabriel Fernandez <gabriel.fernandez@xxxxxx>
This patch introduces the support of the RTC clock.
RTC clock can have 3 sources: lsi, lse and hse_rtc.
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@xxxxxx>
---
drivers/clk/clk-stm32f4.c | 137 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 136 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
index 6427e0f..cbc8148 100644
--- a/drivers/clk/clk-stm32f4.c
+++ b/drivers/clk/clk-stm32f4.c
@@ -126,7 +126,7 @@ struct stm32f4_gate_data {
{ STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" },
};
-enum { SYSTICK, FCLK, CLK_LSI, CLK_LSE, END_PRIMARY_CLK };
+enum { SYSTICK, FCLK, CLK_LSI, CLK_LSE, CLK_HSE_RTC, CLK_RTC, END_PRIMARY_CLK };
/*
* MAX_CLKS is the maximum value in the enumeration below plus the combined
* hweight of stm32f42xx_gate_map (plus one).
@@ -313,6 +313,15 @@ static inline void enable_power_domain_write_protection(void)
regmap_update_bits(pdrm, 0x00, (1 << 8), (0 << 8));
}
+static inline void sofware_reset_backup_domain(void)
+{
+ unsigned long val;
+
+ val = readl(base + STM32F4_RCC_BDCR);
+ writel(val | BIT(16), base + STM32F4_RCC_BDCR);
+ writel(val & ~BIT(16), base + STM32F4_RCC_BDCR);
+}
+
struct stm32_rgate {
struct clk_gate gate;
u8 bit_rdy_idx;
@@ -391,6 +400,111 @@ static struct clk_hw *clk_register_rgate(struct device *dev, const char *name,
return hw;
}
+static int cclk_gate_enable(struct clk_hw *hw)
+{
+ int ret;
+
+ disable_power_domain_write_protection();
+
+ ret = clk_gate_ops.enable(hw);
+
+ enable_power_domain_write_protection();
+
+ return ret;
+}
+
+static void cclk_gate_disable(struct clk_hw *hw)
+{
+ disable_power_domain_write_protection();
+
+ clk_gate_ops.disable(hw);
+
+ enable_power_domain_write_protection();
+}
+
+static int cclk_gate_is_enabled(struct clk_hw *hw)
+{
+ return clk_gate_ops.is_enabled(hw);
+}
+
+static const struct clk_ops cclk_gate_ops = {
+ .enable = cclk_gate_enable,
+ .disable = cclk_gate_disable,
+ .is_enabled = cclk_gate_is_enabled,
+};
+
+static u8 cclk_mux_get_parent(struct clk_hw *hw)
+{
+ return clk_mux_ops.get_parent(hw);
+}
+
+static int cclk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+ int ret;
+
+ disable_power_domain_write_protection();
+
+ sofware_reset_backup_domain();
+
+ ret = clk_mux_ops.set_parent(hw, index);
+
+ enable_power_domain_write_protection();
+
+ return ret;
+}
+
+static const struct clk_ops cclk_mux_ops = {
+ .get_parent = cclk_mux_get_parent,
+ .set_parent = cclk_mux_set_parent,
+};
+
+static struct clk_hw *stm32_register_cclk(struct device *dev, const char *name,
+ const char * const *parent_names, int num_parents,
+ void __iomem *reg, u8 bit_idx, u8 shift, unsigned long flags,
+ spinlock_t *lock)
+{
+ struct clk_hw *hw;
+ struct clk_gate *gate;
+ struct clk_mux *mux;
+
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate) {
+ hw = ERR_PTR(-EINVAL);
+ goto fail;
+ }
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ kfree(gate);
+ hw = ERR_PTR(-EINVAL);
+ goto fail;
+ }
+
+ gate->reg = reg;
+ gate->bit_idx = bit_idx;
+ gate->flags = 0;
+ gate->lock = lock;
+
+ mux->reg = reg;
+ mux->shift = shift;
+ mux->mask = 3;
+ mux->flags = 0;
+
+ hw = clk_hw_register_composite(dev, name, parent_names, num_parents,
+ &mux->hw, &cclk_mux_ops,
+ NULL, NULL,
+ &gate->hw, &cclk_gate_ops,
+ flags);
+
+ if (IS_ERR(hw)) {
+ kfree(gate);
+ kfree(mux);
+ }
+
+fail:
+ return hw;
+}
+
static const char *sys_parents[] __initdata = { "hsi", NULL, "pll" };
static const struct clk_div_table ahb_div_table[] = {
@@ -407,6 +521,10 @@ static struct clk_hw *clk_register_rgate(struct device *dev, const char *name,
{ 0 },
};
+static const char *rtc_parents[4] = {
+ "no-clock", "lse", "lsi", "hse-rtc"
+};
+
static void __init stm32f4_rcc_init(struct device_node *np)
{
const char *hse_clk;
@@ -492,6 +610,23 @@ static void __init stm32f4_rcc_init(struct device_node *np)
goto fail;
}
+ clks[CLK_HSE_RTC] = clk_hw_register_divider(NULL, "hse-rtc", "clk-hse",
+ 0, base + STM32F4_RCC_CFGR, 16, 5, 0,
+ &stm32f4_clk_lock);
+
+ if (IS_ERR(clks[CLK_HSE_RTC])) {
+ pr_err("Unable to register hse-rtc clock\n");
+ goto fail;
+ }
+
+ clks[CLK_RTC] = stm32_register_cclk(NULL, "rtc", rtc_parents, 4,
+ base + STM32F4_RCC_BDCR, 15, 8, 0, &stm32f4_clk_lock);
+
+ if (IS_ERR(clks[CLK_RTC])) {
+ pr_err("Unable to register rtc clock\n");
+ goto fail;
+ }
+
of_clk_add_hw_provider(np, stm32f4_rcc_lookup_clk, NULL);
return;
fail:
--
1.9.1
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