[PATCH v4 05/14] clk: stm32mp13: add stm32 divider clock

gabriel.fernandez
2022-05-16T07:08:08Z

Just to introduce management of a stm32 divider clock

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
---
drivers/clk/stm32/clk-stm32-core.c | 159 +++++++++++++++++++++++++++++
drivers/clk/stm32/clk-stm32-core.h | 21 ++++
drivers/clk/stm32/clk-stm32mp13.c | 7 ++
3 files changed, 187 insertions(+)

diff --git a/drivers/clk/stm32/clk-stm32-core.c b/drivers/clk/stm32/clk-stm32-core.c
index ca2605da873d..da38eca2b8c5 100644
--- a/drivers/clk/stm32/clk-stm32-core.c
+++ b/drivers/clk/stm32/clk-stm32-core.c
@@ -175,6 +175,80 @@ static int stm32_gate_is_enabled(void __iomem *base,
return (readl(base + gate->offset) & BIT(gate->bit_idx)) != 0;
}

+static unsigned int _get_table_div(const struct clk_div_table *table,
+ unsigned int val)
+{
+ const struct clk_div_table *clkt;
+
+ for (clkt = table; clkt->div; clkt++)
+ if (clkt->val == val)
+ return clkt->div;
+ return 0;
+}
+
+static unsigned int _get_div(const struct clk_div_table *table,
+ unsigned int val, unsigned long flags, u8 width)
+{
+ if (flags & CLK_DIVIDER_ONE_BASED)
+ return val;
+ if (flags & CLK_DIVIDER_POWER_OF_TWO)
+ return 1 << val;
+ if (table)
+ return _get_table_div(table, val);
+ return val + 1;
+}
+
+static unsigned long stm32_divider_get_rate(void __iomem *base,
+ struct clk_stm32_clock_data *data,
+ u16 div_id,
+ unsigned long parent_rate)
+{
+ const struct stm32_div_cfg *divider = &data->dividers[div_id];
+ unsigned int val;
+ unsigned int div;
+
+ val = readl(base + divider->offset) >> divider->shift;
+ val &= clk_div_mask(divider->width);
+ div = _get_div(divider->table, val, divider->flags, divider->width);
+
+ if (!div) {
+ WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),
+ "%d: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
+ div_id);
+ return parent_rate;
+ }
+
+ return DIV_ROUND_UP_ULL((u64)parent_rate, div);
+}
+
+static int stm32_divider_set_rate(void __iomem *base,
+ struct clk_stm32_clock_data *data,
+ u16 div_id, unsigned long rate,
+ unsigned long parent_rate)
+{
+ const struct stm32_div_cfg *divider = &data->dividers[div_id];
+ int value;
+ u32 val;
+
+ value = divider_get_val(rate, parent_rate, divider->table,
+ divider->width, divider->flags);
+ if (value < 0)
+ return value;
+
+ if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
+ val = clk_div_mask(divider->width) << (divider->shift + 16);
+ } else {
+ val = readl(base + divider->offset);
+ val &= ~(clk_div_mask(divider->width) << divider->shift);
+ }
+
+ val |= (u32)value << divider->shift;
+
+ writel(val, base + divider->offset);
+
+ return 0;
+}
+
static u8 clk_stm32_mux_get_parent(struct clk_hw *hw)
{
struct clk_stm32_mux *mux = to_clk_stm32_mux(hw);
@@ -251,6 +325,70 @@ const struct clk_ops clk_stm32_gate_ops = {
.disable_unused = clk_stm32_gate_disable_unused,
};

+static int clk_stm32_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_stm32_div *div = to_clk_stm32_divider(hw);
+ unsigned long flags = 0;
+ int ret;
+
+ if (div->div_id == NO_STM32_DIV)
+ return rate;
+
+ spin_lock_irqsave(div->lock, flags);
+
+ ret = stm32_divider_set_rate(div->base, div->clock_data, div->div_id, rate, parent_rate);
+
+ spin_unlock_irqrestore(div->lock, flags);
+
+ return ret;
+}
+
+static long clk_stm32_divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_stm32_div *div = to_clk_stm32_divider(hw);
+ const struct stm32_div_cfg *divider;
+
+ if (div->div_id == NO_STM32_DIV)
+ return rate;
+
+ divider = &div->clock_data->dividers[div->div_id];
+
+ /* if read only, just return current value */
+ if (divider->flags & CLK_DIVIDER_READ_ONLY) {
+ u32 val;
+
+ val = readl(div->base + divider->offset) >> divider->shift;
+ val &= clk_div_mask(divider->width);
+
+ return divider_ro_round_rate(hw, rate, prate, divider->table,
+ divider->width, divider->flags,
+ val);
+ }
+
+ return divider_round_rate_parent(hw, clk_hw_get_parent(hw),
+ rate, prate, divider->table,
+ divider->width, divider->flags);
+}
+
+static unsigned long clk_stm32_divider_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_stm32_div *div = to_clk_stm32_divider(hw);
+
+ if (div->div_id == NO_STM32_DIV)
+ return parent_rate;
+
+ return stm32_divider_get_rate(div->base, div->clock_data, div->div_id, parent_rate);
+}
+
+const struct clk_ops clk_stm32_divider_ops = {
+ .recalc_rate = clk_stm32_divider_recalc_rate,
+ .round_rate = clk_stm32_divider_round_rate,
+ .set_rate = clk_stm32_divider_set_rate,
+};
+
struct clk_hw *clk_stm32_mux_register(struct device *dev,
const struct stm32_rcc_match_data *data,
void __iomem *base,
@@ -292,3 +430,24 @@ struct clk_hw *clk_stm32_gate_register(struct device *dev,

return hw;
}
+
+struct clk_hw *clk_stm32_div_register(struct device *dev,
+ const struct stm32_rcc_match_data *data,
+ void __iomem *base,
+ spinlock_t *lock,
+ const struct clock_config *cfg)
+{
+ struct clk_stm32_div *div = cfg->clock_cfg;
+ struct clk_hw *hw = &div->hw;
+ int err;
+
+ div->base = base;
+ div->lock = lock;
+ div->clock_data = data->clock_data;
+
+ err = clk_hw_register(dev, hw);
+ if (err)
+ return ERR_PTR(err);
+
+ return hw;
+}
diff --git a/drivers/clk/stm32/clk-stm32-core.h b/drivers/clk/stm32/clk-stm32-core.h
index f958ef610f72..c2de58a22aa8 100644
--- a/drivers/clk/stm32/clk-stm32-core.h
+++ b/drivers/clk/stm32/clk-stm32-core.h
@@ -104,9 +104,20 @@ struct clk_stm32_gate {

#define to_clk_stm32_gate(_hw) container_of(_hw, struct clk_stm32_gate, hw)

+struct clk_stm32_div {
+ u16 div_id;
+ struct clk_hw hw;
+ void __iomem *base;
+ struct clk_stm32_clock_data *clock_data;
+ spinlock_t *lock; /* spin lock */
+};
+
+#define to_clk_stm32_divider(_hw) container_of(_hw, struct clk_stm32_div, hw)
+
/* Clock operators */
extern const struct clk_ops clk_stm32_mux_ops;
extern const struct clk_ops clk_stm32_gate_ops;
+extern const struct clk_ops clk_stm32_divider_ops;

/* Clock registering */
struct clk_hw *clk_stm32_mux_register(struct device *dev,
@@ -121,6 +132,12 @@ struct clk_hw *clk_stm32_gate_register(struct device *dev,
spinlock_t *lock,
const struct clock_config *cfg);

+struct clk_hw *clk_stm32_div_register(struct device *dev,
+ const struct stm32_rcc_match_data *data,
+ void __iomem *base,
+ spinlock_t *lock,
+ const struct clock_config *cfg);
+
#define STM32_CLOCK_CFG(_binding, _clk, _struct, _register)\
{\
.id = (_binding),\
@@ -135,3 +152,7 @@ struct clk_hw *clk_stm32_gate_register(struct device *dev,
#define STM32_GATE_CFG(_binding, _clk)\
STM32_CLOCK_CFG(_binding, &(_clk), struct clk_stm32_gate *,\
&clk_stm32_gate_register)
+
+#define STM32_DIV_CFG(_binding, _clk)\
+ STM32_CLOCK_CFG(_binding, &(_clk), struct clk_stm32_div *,\
+ &clk_stm32_div_register)
diff --git a/drivers/clk/stm32/clk-stm32mp13.c b/drivers/clk/stm32/clk-stm32mp13.c
index 55326d4d34dd..d93d92b5fe82 100644
--- a/drivers/clk/stm32/clk-stm32mp13.c
+++ b/drivers/clk/stm32/clk-stm32mp13.c
@@ -415,9 +415,16 @@ static struct clk_stm32_gate eth1ck_k = {
.hw.init = CLK_HW_INIT_HW("eth1ck_k", &ck_ker_eth1.hw, &clk_stm32_gate_ops, 0),
};

+static struct clk_stm32_div eth1ptp_k = {
+ .div_id = DIV_ETH1PTP,
+ .hw.init = CLK_HW_INIT_HW("eth1ptp_k", &ck_ker_eth1.hw, &clk_stm32_divider_ops,
+ CLK_SET_RATE_NO_REPARENT),
+};
+
static const struct clock_config stm32mp13_clock_cfg[] = {
STM32_MUX_CFG(NO_ID, ck_ker_eth1),
STM32_GATE_CFG(ETH1CK_K, eth1ck_k),
+ STM32_DIV_CFG(ETH1PTP_K, eth1ptp_k),
};

static u16 stm32mp13_cpt_gate[GATE_NB];
--
2.25.1