clk: stm32: Introduce STM32MP13 RCC drivers (Reset Clock Controller)

This driver manages Reset and Clock of STM32MP13 soc.
It uses a clk-stm32-core module to manage stm32 gate, mux and divider
for STM32MP13 and for new future soc.

All gates, muxes, dividers are identify by an index and information
are stored in array (register address, shift, with, flags...)
This is useful when we have two clocks with the same gate or
when one mux manages two output clocks.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Link: https://lore.kernel.org/r/20220516070600.7692-3-gabriel.fernandez@foss.st.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/Kconfig

@@ -368,6 +368,11 @@ config COMMON_CLK_VC5
 	  This driver supports the IDT VersaClock 5 and VersaClock 6
 	  programmable clock generators.
 
+config COMMON_CLK_STM32MP135
+	def_bool COMMON_CLK && MACH_STM32MP13
+	help
+	  Support for stm32mp135 SoC family clocks
+
 config COMMON_CLK_STM32MP157
 	def_bool COMMON_CLK && MACH_STM32MP157
 	help

drivers/clk/Makefile

@@ -115,6 +115,7 @@ obj-y					+= socfpga/
 obj-$(CONFIG_PLAT_SPEAR)		+= spear/
 obj-y					+= sprd/
 obj-$(CONFIG_ARCH_STI)			+= st/
+obj-$(CONFIG_ARCH_STM32)		+= stm32/
 obj-$(CONFIG_SOC_STARFIVE)		+= starfive/
 obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
 obj-y					+= sunxi-ng/

drivers/clk/stm32/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_COMMON_CLK_STM32MP135)	+= clk-stm32mp13.o clk-stm32-core.o reset-stm32.o

drivers/clk/stm32/clk-stm32-core.c

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2022 - All Rights Reserved
+ * Author: Gabriel Fernandez <gabriel.fernandez@foss.st.com> for STMicroelectronics.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "clk-stm32-core.h"
+#include "reset-stm32.h"
+
+static DEFINE_SPINLOCK(rlock);
+
+static int stm32_rcc_clock_init(struct device *dev,
+				const struct of_device_id *match,
+				void __iomem *base)
+{
+	const struct stm32_rcc_match_data *data = match->data;
+	struct clk_hw_onecell_data *clk_data = data->hw_clks;
+	struct device_node *np = dev_of_node(dev);
+	struct clk_hw **hws;
+	int n, max_binding;
+
+	max_binding =  data->maxbinding;
+
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, max_binding), GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	clk_data->num = max_binding;
+
+	hws = clk_data->hws;
+
+	for (n = 0; n < max_binding; n++)
+		hws[n] = ERR_PTR(-ENOENT);
+
+	for (n = 0; n < data->num_clocks; n++) {
+		const struct clock_config *cfg_clock = &data->tab_clocks[n];
+		struct clk_hw *hw = ERR_PTR(-ENOENT);
+
+		if (cfg_clock->func)
+			hw = (*cfg_clock->func)(dev, data, base, &rlock,
+						cfg_clock);
+
+		if (IS_ERR(hw)) {
+			dev_err(dev, "Can't register clk %d: %ld\n", n,
+				PTR_ERR(hw));
+			return PTR_ERR(hw);
+		}
+
+		if (cfg_clock->id != NO_ID)
+			hws[cfg_clock->id] = hw;
+	}
+
+	return of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_data);
+}
+
+int stm32_rcc_init(struct device *dev, const struct of_device_id *match_data,
+		   void __iomem *base)
+{
+	const struct of_device_id *match;
+	int err;
+
+	match = of_match_node(match_data, dev_of_node(dev));
+	if (!match) {
+		dev_err(dev, "match data not found\n");
+		return -ENODEV;
+	}
+
+	/* RCC Reset Configuration */
+	err = stm32_rcc_reset_init(dev, match, base);
+	if (err) {
+		pr_err("stm32 reset failed to initialize\n");
+		return err;
+	}
+
+	/* RCC Clock Configuration */
+	err = stm32_rcc_clock_init(dev, match, base);
+	if (err) {
+		pr_err("stm32 clock failed to initialize\n");
+		return err;
+	}
+
+	return 0;
+}

drivers/clk/stm32/clk-stm32-core.h

@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0  */
+/*
+ * Copyright (C) STMicroelectronics 2022 - All Rights Reserved
+ * Author: Gabriel Fernandez <gabriel.fernandez@foss.st.com> for STMicroelectronics.
+ */
+
+#include <linux/clk-provider.h>
+
+struct stm32_rcc_match_data;
+
+struct stm32_mux_cfg {
+	u16	offset;
+	u8	shift;
+	u8	width;
+	u8	flags;
+	u32	*table;
+	u8	ready;
+};
+
+struct stm32_gate_cfg {
+	u16	offset;
+	u8	bit_idx;
+	u8	set_clr;
+};
+
+struct stm32_div_cfg {
+	u16	offset;
+	u8	shift;
+	u8	width;
+	u8	flags;
+	u8	ready;
+	const struct clk_div_table *table;
+};
+
+struct stm32_composite_cfg {
+	int	mux;
+	int	gate;
+	int	div;
+};
+
+#define NO_ID 0xFFFFFFFF
+
+#define NO_STM32_MUX		0xFFFF
+#define NO_STM32_DIV		0xFFFF
+#define NO_STM32_GATE		0xFFFF
+
+struct clock_config {
+	unsigned long	id;
+	void		*clock_cfg;
+
+	struct clk_hw *(*func)(struct device *dev,
+			       const struct stm32_rcc_match_data *data,
+			       void __iomem *base,
+			       spinlock_t *lock,
+			       const struct clock_config *cfg);
+};
+
+struct clk_stm32_clock_data {
+	u16 *gate_cpt;
+	const struct stm32_gate_cfg	*gates;
+	const struct stm32_mux_cfg	*muxes;
+	const struct stm32_div_cfg	*dividers;
+};
+
+struct stm32_rcc_match_data {
+	struct clk_hw_onecell_data	*hw_clks;
+	unsigned int			num_clocks;
+	const struct clock_config	*tab_clocks;
+	unsigned int			maxbinding;
+	struct clk_stm32_clock_data	*clock_data;
+	u32				clear_offset;
+};
+
+int stm32_rcc_reset_init(struct device *dev, const struct of_device_id *match,
+			 void __iomem *base);
+
+int stm32_rcc_init(struct device *dev, const struct of_device_id *match_data,
+		   void __iomem *base);
+
+/* MUX define */
+#define MUX_NO_RDY		0xFF
+
+/* DIV define */
+#define DIV_NO_RDY		0xFF
+
+/* Clock registering */
+#define STM32_CLOCK_CFG(_binding, _clk, _struct, _register)\
+{\
+	.id		= (_binding),\
+	.clock_cfg	= (_struct) {_clk},\
+	.func		= (_register),\
+}

drivers/clk/stm32/reset-stm32.c

@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2022 - All Rights Reserved
+ * Author: Gabriel Fernandez <gabriel.fernandez@foss.st.com> for STMicroelectronics.
+ */
+
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "clk-stm32-core.h"
+
+#define STM32_RESET_ID_MASK GENMASK(15, 0)
+
+struct stm32_reset_data {
+	/* reset lock */
+	spinlock_t			lock;
+	struct reset_controller_dev	rcdev;
+	void __iomem			*membase;
+	u32				clear_offset;
+};
+
+static inline struct stm32_reset_data *
+to_stm32_reset_data(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct stm32_reset_data, rcdev);
+}
+
+static int stm32_reset_update(struct reset_controller_dev *rcdev,
+			      unsigned long id, bool assert)
+{
+	struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+
+	if (data->clear_offset) {
+		void __iomem *addr;
+
+		addr = data->membase + (bank * reg_width);
+		if (!assert)
+			addr += data->clear_offset;
+
+		writel(BIT(offset), addr);
+
+	} else {
+		unsigned long flags;
+		u32 reg;
+
+		spin_lock_irqsave(&data->lock, flags);
+
+		reg = readl(data->membase + (bank * reg_width));
+
+		if (assert)
+			reg |= BIT(offset);
+		else
+			reg &= ~BIT(offset);
+
+		writel(reg, data->membase + (bank * reg_width));
+
+		spin_unlock_irqrestore(&data->lock, flags);
+	}
+
+	return 0;
+}
+
+static int stm32_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	return stm32_reset_update(rcdev, id, true);
+}
+
+static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	return stm32_reset_update(rcdev, id, false);
+}
+
+static int stm32_reset_status(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+	u32 reg;
+
+	reg = readl(data->membase + (bank * reg_width));
+
+	return !!(reg & BIT(offset));
+}
+
+static const struct reset_control_ops stm32_reset_ops = {
+	.assert		= stm32_reset_assert,
+	.deassert	= stm32_reset_deassert,
+	.status		= stm32_reset_status,
+};
+
+int stm32_rcc_reset_init(struct device *dev, const struct of_device_id *match,
+			 void __iomem *base)
+{
+	const struct stm32_rcc_match_data *data = match->data;
+	struct stm32_reset_data *reset_data = NULL;
+
+	data = match->data;
+
+	reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
+	if (!reset_data)
+		return -ENOMEM;
+
+	reset_data->membase = base;
+	reset_data->rcdev.owner = THIS_MODULE;
+	reset_data->rcdev.ops = &stm32_reset_ops;
+	reset_data->rcdev.of_node = dev_of_node(dev);
+	reset_data->rcdev.nr_resets = STM32_RESET_ID_MASK;
+	reset_data->clear_offset = data->clear_offset;
+
+	return reset_controller_register(&reset_data->rcdev);
+}

drivers/clk/stm32/reset-stm32.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0  */
+/*
+ * Copyright (C) STMicroelectronics 2022 - All Rights Reserved
+ * Author: Gabriel Fernandez <gabriel.fernandez@foss.st.com> for STMicroelectronics.
+ */
+
+int stm32_rcc_reset_init(struct device *dev, const struct of_device_id *match,
+			 void __iomem *base);