clk: Add Microchip PolarFire SoC clock driver

Add clock driver code for the Microchip PolarFire SoC. This driver
handles reset and clock control of the Microchip PolarFire SoC device.

Signed-off-by: Padmarao Begari <padmarao.begari@microchip.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Bin Meng <bin.meng@windriver.com>

drivers/clk/Kconfig

@@ -165,6 +165,7 @@ source "drivers/clk/exynos/Kconfig"
 source "drivers/clk/imx/Kconfig"
 source "drivers/clk/kendryte/Kconfig"
 source "drivers/clk/meson/Kconfig"
+source "drivers/clk/microchip/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
 source "drivers/clk/owl/Kconfig"
 source "drivers/clk/renesas/Kconfig"

drivers/clk/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_$(SPL_TPL_)CLK_INTEL) += intel/
 obj-$(CONFIG_CLK_HSDK) += clk-hsdk-cgu.o
 obj-$(CONFIG_CLK_K210) += kendryte/
 obj-$(CONFIG_CLK_MPC83XX) += mpc83xx_clk.o
+obj-$(CONFIG_CLK_MPFS) += microchip/
 obj-$(CONFIG_CLK_OCTEON) += clk_octeon.o
 obj-$(CONFIG_CLK_OWL) += owl/
 obj-$(CONFIG_CLK_RENESAS) += renesas/

drivers/clk/microchip/Kconfig

@@ -0,0 +1,5 @@
+config CLK_MPFS
+	bool "Clock support for Microchip PolarFire SoC"
+	depends on CLK && CLK_CCF
+	help
+	  This enables support clock driver for Microchip PolarFire SoC platform.

drivers/clk/microchip/Makefile

@@ -0,0 +1 @@
+obj-y += mpfs_clk.o mpfs_clk_cfg.o mpfs_clk_periph.o

drivers/clk/microchip/mpfs_clk.c

@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari@microchip.com>
+ */
+#include <common.h>
+#include <clk.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <log.h>
+#include <dm/device.h>
+#include <dm/devres.h>
+#include <dm/uclass.h>
+#include <linux/err.h>
+
+#include "mpfs_clk.h"
+
+/* All methods are delegated to CCF clocks */
+
+static ulong mpfs_clk_get_rate(struct clk *clk)
+{
+	struct clk *c;
+	int err = clk_get_by_id(clk->id, &c);
+
+	if (err)
+		return err;
+	return clk_get_rate(c);
+}
+
+static ulong mpfs_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	struct clk *c;
+	int err = clk_get_by_id(clk->id, &c);
+
+	if (err)
+		return err;
+	return clk_set_rate(c, rate);
+}
+
+static int mpfs_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct clk *c, *p;
+	int err = clk_get_by_id(clk->id, &c);
+
+	if (err)
+		return err;
+
+	err = clk_get_by_id(parent->id, &p);
+	if (err)
+		return err;
+
+	return clk_set_parent(c, p);
+}
+
+static int mpfs_clk_endisable(struct clk *clk, bool enable)
+{
+	struct clk *c;
+	int err = clk_get_by_id(clk->id, &c);
+
+	if (err)
+		return err;
+	return enable ? clk_enable(c) : clk_disable(c);
+}
+
+static int mpfs_clk_enable(struct clk *clk)
+{
+	return mpfs_clk_endisable(clk, true);
+}
+
+static int mpfs_clk_disable(struct clk *clk)
+{
+	return mpfs_clk_endisable(clk, false);
+}
+
+static int mpfs_clk_probe(struct udevice *dev)
+{
+	int ret;
+	void __iomem *base;
+	u32 clk_rate;
+	const char *parent_clk_name;
+	struct clk *clk = dev_get_priv(dev);
+
+	base = dev_read_addr_ptr(dev);
+	if (!base)
+		return -EINVAL;
+
+	ret = clk_get_by_index(dev, 0, clk);
+	if (ret)
+		return ret;
+
+	dev_read_u32(clk->dev, "clock-frequency", &clk_rate);
+	parent_clk_name = clk->dev->name;
+
+	ret = mpfs_clk_register_cfgs(base, clk_rate, parent_clk_name);
+	if (ret)
+		return ret;
+
+	ret = mpfs_clk_register_periphs(base, clk_rate, "clk_ahb");
+
+	return ret;
+}
+
+static const struct clk_ops mpfs_clk_ops = {
+	.set_rate = mpfs_clk_set_rate,
+	.get_rate = mpfs_clk_get_rate,
+	.set_parent = mpfs_clk_set_parent,
+	.enable = mpfs_clk_enable,
+	.disable = mpfs_clk_disable,
+};
+
+static const struct udevice_id mpfs_of_match[] = {
+	{ .compatible = "microchip,mpfs-clkcfg" },
+	{ }
+};
+
+U_BOOT_DRIVER(mpfs_clk) = {
+	.name = "mpfs_clk",
+	.id = UCLASS_CLK,
+	.of_match = mpfs_of_match,
+	.ops = &mpfs_clk_ops,
+	.probe = mpfs_clk_probe,
+	.priv_auto = sizeof(struct clk),
+};

drivers/clk/microchip/mpfs_clk.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2020 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari@microchip.com>
+ */
+#ifndef __MICROCHIP_MPFS_CLK_H
+#define __MICROCHIP_MPFS_CLK_H
+
+#include <linux/clk-provider.h>
+/**
+ * mpfs_clk_register_cfgs() - register configuration clocks
+ *
+ * @base: base address of the mpfs system register.
+ * @clk_rate: the mpfs pll clock rate.
+ * @parent_name: a pointer to parent clock name.
+ * @return zero on success, or a negative error code.
+ */
+int mpfs_clk_register_cfgs(void __iomem *base, u32 clk_rate,
+			   const char *parent_name);
+/**
+ * mpfs_clk_register_periphs() - register peripheral clocks
+ *
+ * @base: base address of the mpfs system register.
+ * @clk_rate: the mpfs pll clock rate.
+ * @parent_name: a pointer to parent clock name.
+ * @return zero on success, or a negative error code.
+ */
+int mpfs_clk_register_periphs(void __iomem *base, u32 clk_rate,
+			      const char *parent_name);
+/**
+ * divider_get_val() - get the clock divider value
+ *
+ * @rate: requested clock rate.
+ * @parent_rate: parent clock rate.
+ * @table: a pointer to clock divider table.
+ * @width: width of the divider bit field.
+ * @flags: common clock framework flags.
+ * @return divider value on success, or a negative error code.
+ */
+int divider_get_val(unsigned long rate, unsigned long parent_rate,
+		    const struct clk_div_table *table,
+		    u8 width, unsigned long flags);
+
+#endif	/* __MICROCHIP_MPFS_CLK_H */

drivers/clk/microchip/mpfs_clk_cfg.c

@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari@microchip.com>
+ */
+#include <common.h>
+#include <clk.h>
+#include <clk-uclass.h>
+#include <asm/io.h>
+#include <dm/device.h>
+#include <dm/devres.h>
+#include <dm/uclass.h>
+#include <dt-bindings/clock/microchip-mpfs-clock.h>
+#include <linux/err.h>
+
+#include "mpfs_clk.h"
+
+#define MPFS_CFG_CLOCK "mpfs_cfg_clock"
+
+#define REG_CLOCK_CONFIG_CR 0x08
+
+/* CPU and AXI clock divisors */
+static const struct clk_div_table mpfs_div_cpu_axi_table[] = {
+	{ 0, 1 }, { 1, 2 }, { 2, 4 }, { 3, 8 },
+	{ 0, 0 }
+};
+
+/* AHB clock divisors */
+static const struct clk_div_table mpfs_div_ahb_table[] = {
+	{ 1, 2 }, { 2, 4}, { 3, 8 },
+	{ 0, 0 }
+};
+
+/**
+ * struct mpfs_cfg_clock - per instance of configuration clock
+ * @id: index of a configuration clock
+ * @name: name of a configuration clock
+ * @shift: shift to the divider bit field of a configuration clock
+ * @width: width of the divider bit field of a configation clock
+ * @table: clock divider table instance
+ * @flags: common clock framework flags
+ */
+struct mpfs_cfg_clock {
+	unsigned int id;
+	const char *name;
+	u8 shift;
+	u8 width;
+	const struct clk_div_table *table;
+	unsigned long flags;
+};
+
+/**
+ * struct mpfs_cfg_hw_clock - hardware configuration clock (cpu, axi, ahb)
+ * @cfg: configuration clock instance
+ * @sys_base: base address of the mpfs system register
+ * @prate: the pll clock rate
+ * @hw: clock instance
+ */
+struct mpfs_cfg_hw_clock {
+	struct mpfs_cfg_clock cfg;
+	void __iomem *sys_base;
+	u32 prate;
+	struct clk hw;
+};
+
+#define to_mpfs_cfg_clk(_hw) container_of(_hw, struct mpfs_cfg_hw_clock, hw)
+
+static ulong mpfs_cfg_clk_recalc_rate(struct clk *hw)
+{
+	struct mpfs_cfg_hw_clock *cfg_hw = to_mpfs_cfg_clk(hw);
+	struct mpfs_cfg_clock *cfg = &cfg_hw->cfg;
+	void __iomem *base_addr = cfg_hw->sys_base;
+	unsigned long rate;
+	u32 val;
+
+	val = readl(base_addr + REG_CLOCK_CONFIG_CR) >> cfg->shift;
+	val &= clk_div_mask(cfg->width);
+	rate = cfg_hw->prate / (1u << val);
+	hw->rate = rate;
+
+	return rate;
+}
+
+static ulong mpfs_cfg_clk_set_rate(struct clk *hw, ulong rate)
+{
+	struct mpfs_cfg_hw_clock *cfg_hw = to_mpfs_cfg_clk(hw);
+	struct mpfs_cfg_clock *cfg = &cfg_hw->cfg;
+	void __iomem *base_addr = cfg_hw->sys_base;
+	u32  val;
+	int divider_setting;
+
+	divider_setting = divider_get_val(rate, cfg_hw->prate, cfg->table, cfg->width, cfg->flags);
+
+	if (divider_setting < 0)
+		return divider_setting;
+
+	val = readl(base_addr + REG_CLOCK_CONFIG_CR);
+	val &= ~(clk_div_mask(cfg->width) << cfg_hw->cfg.shift);
+	val |= divider_setting << cfg->shift;
+	writel(val, base_addr + REG_CLOCK_CONFIG_CR);
+
+	return clk_get_rate(hw);
+}
+
+#define CLK_CFG(_id, _name, _shift, _width, _table, _flags) {	\
+		.cfg.id = _id,					\
+		.cfg.name = _name,				\
+		.cfg.shift = _shift,				\
+		.cfg.width = _width,				\
+		.cfg.table = _table,				\
+		.cfg.flags = _flags,				\
+	}
+
+static struct mpfs_cfg_hw_clock mpfs_cfg_clks[] = {
+	CLK_CFG(CLK_CPU, "clk_cpu", 0, 2, mpfs_div_cpu_axi_table, 0),
+	CLK_CFG(CLK_AXI, "clk_axi", 2, 2, mpfs_div_cpu_axi_table, 0),
+	CLK_CFG(CLK_AHB, "clk_ahb", 4, 2, mpfs_div_ahb_table, 0),
+};
+
+int mpfs_clk_register_cfgs(void __iomem *base, u32 clk_rate,
+			   const char *parent_name)
+{
+	int ret;
+	int i, id, num_clks;
+	const char *name;
+	struct clk *hw;
+
+	num_clks = ARRAY_SIZE(mpfs_cfg_clks);
+	for (i = 0; i < num_clks; i++) {
+		hw = &mpfs_cfg_clks[i].hw;
+		mpfs_cfg_clks[i].sys_base = base;
+		mpfs_cfg_clks[i].prate = clk_rate;
+		name = mpfs_cfg_clks[i].cfg.name;
+		ret = clk_register(hw, MPFS_CFG_CLOCK, name, parent_name);
+		if (ret)
+			ERR_PTR(ret);
+		id = mpfs_cfg_clks[i].cfg.id;
+		clk_dm(id, hw);
+	}
+	return 0;
+}
+
+const struct clk_ops mpfs_cfg_clk_ops = {
+	.set_rate = mpfs_cfg_clk_set_rate,
+	.get_rate = mpfs_cfg_clk_recalc_rate,
+};
+
+U_BOOT_DRIVER(mpfs_cfg_clock) = {
+	.name	= MPFS_CFG_CLOCK,
+	.id	= UCLASS_CLK,
+	.ops	= &mpfs_cfg_clk_ops,
+};

drivers/clk/microchip/mpfs_clk_periph.c

@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari@microchip.com>
+ */
+#include <common.h>
+#include <clk.h>
+#include <clk-uclass.h>
+#include <asm/io.h>
+#include <dm/device.h>
+#include <dm/devres.h>
+#include <dm/uclass.h>
+#include <dt-bindings/clock/microchip-mpfs-clock.h>
+#include <linux/err.h>
+
+#include "mpfs_clk.h"
+
+#define MPFS_PERIPH_CLOCK "mpfs_periph_clock"
+
+#define REG_CLOCK_CONFIG_CR 0x08
+#define REG_SUBBLK_CLOCK_CR 0x84
+#define REG_SUBBLK_RESET_CR 0x88
+
+#define CFG_CPU_SHIFT   0x0
+#define CFG_AXI_SHIFT   0x2
+#define CFG_AHB_SHIFT   0x4
+#define CFG_WIDTH       0x2
+
+/**
+ * struct mpfs_periph_clock - per instance of peripheral clock
+ * @id: index of a peripheral clock
+ * @name: name of a peripheral clock
+ * @shift: shift to a peripheral clock bit field
+ * @flags: common clock framework flags
+ */
+struct mpfs_periph_clock {
+	unsigned int id;
+	const char *name;
+	u8 shift;
+	unsigned long flags;
+};
+
+/**
+ * struct mpfs_periph_hw_clock - hardware peripheral clock
+ * @periph: peripheral clock instance
+ * @sys_base: base address of the mpfs system register
+ * @prate: the pll clock rate
+ * @hw: clock instance
+ */
+struct mpfs_periph_hw_clock {
+	struct mpfs_periph_clock periph;
+	void __iomem *sys_base;
+	u32 prate;
+	struct clk hw;
+};
+
+#define to_mpfs_periph_clk(_hw) container_of(_hw, struct mpfs_periph_hw_clock, hw)
+
+static int mpfs_periph_clk_enable(struct clk *hw)
+{
+	struct mpfs_periph_hw_clock *periph_hw = to_mpfs_periph_clk(hw);
+	struct mpfs_periph_clock *periph = &periph_hw->periph;
+	void __iomem *base_addr = periph_hw->sys_base;
+	u32 reg, val;
+
+	if (periph->flags != CLK_IS_CRITICAL) {
+		reg = readl(base_addr + REG_SUBBLK_RESET_CR);
+		val = reg & ~(1u << periph->shift);
+		writel(val, base_addr + REG_SUBBLK_RESET_CR);
+
+		reg = readl(base_addr + REG_SUBBLK_CLOCK_CR);
+		val = reg | (1u << periph->shift);
+		writel(val, base_addr + REG_SUBBLK_CLOCK_CR);
+	}
+
+	return 0;
+}
+
+static int mpfs_periph_clk_disable(struct clk *hw)
+{
+	struct mpfs_periph_hw_clock *periph_hw = to_mpfs_periph_clk(hw);
+	struct mpfs_periph_clock *periph = &periph_hw->periph;
+	void __iomem *base_addr = periph_hw->sys_base;
+	u32 reg, val;
+
+	if (periph->flags != CLK_IS_CRITICAL) {
+		reg = readl(base_addr + REG_SUBBLK_RESET_CR);
+		val = reg | (1u << periph->shift);
+		writel(val, base_addr + REG_SUBBLK_RESET_CR);
+
+		reg = readl(base_addr + REG_SUBBLK_CLOCK_CR);
+		val = reg & ~(1u << periph->shift);
+		writel(val, base_addr + REG_SUBBLK_CLOCK_CR);
+	}
+
+	return 0;
+}
+
+static ulong mpfs_periph_clk_recalc_rate(struct clk *hw)
+{
+	struct mpfs_periph_hw_clock *periph_hw = to_mpfs_periph_clk(hw);
+	void __iomem *base_addr = periph_hw->sys_base;
+	unsigned long rate;
+	u32 val;
+
+	val = readl(base_addr + REG_CLOCK_CONFIG_CR) >> CFG_AHB_SHIFT;
+	val &= clk_div_mask(CFG_WIDTH);
+	rate = periph_hw->prate / (1u << val);
+	hw->rate = rate;
+
+	return rate;
+}
+
+#define CLK_PERIPH(_id, _name, _shift, _flags) {	\
+		.periph.id = _id,			\
+		.periph.name = _name,			\
+		.periph.shift = _shift,			\
+		.periph.flags = _flags,			\
+	}
+
+static struct mpfs_periph_hw_clock mpfs_periph_clks[] = {
+	CLK_PERIPH(CLK_ENVM, "clk_periph_envm", 0, CLK_IS_CRITICAL),
+	CLK_PERIPH(CLK_MAC0, "clk_periph_mac0", 1, 0),
+	CLK_PERIPH(CLK_MAC1, "clk_periph_mac1", 2, 0),
+	CLK_PERIPH(CLK_MMC, "clk_periph_mmc", 3, 0),
+	CLK_PERIPH(CLK_TIMER, "clk_periph_timer", 4, 0),
+	CLK_PERIPH(CLK_MMUART0, "clk_periph_mmuart0", 5, 0),
+	CLK_PERIPH(CLK_MMUART1, "clk_periph_mmuart1", 6, 0),
+	CLK_PERIPH(CLK_MMUART2, "clk_periph_mmuart2", 7, 0),
+	CLK_PERIPH(CLK_MMUART3, "clk_periph_mmuart3", 8, 0),
+	CLK_PERIPH(CLK_MMUART4, "clk_periph_mmuart4", 9, 0),
+	CLK_PERIPH(CLK_SPI0, "clk_periph_spi0", 10, 0),
+	CLK_PERIPH(CLK_SPI1, "clk_periph_spi1", 11, 0),
+	CLK_PERIPH(CLK_I2C0, "clk_periph_i2c0", 12, 0),
+	CLK_PERIPH(CLK_I2C1, "clk_periph_i2c1", 13, 0),
+	CLK_PERIPH(CLK_CAN0, "clk_periph_can0", 14, 0),
+	CLK_PERIPH(CLK_CAN1, "clk_periph_can1", 15, 0),
+	CLK_PERIPH(CLK_USB, "clk_periph_usb", 16, 0),
+	CLK_PERIPH(CLK_RTC, "clk_periph_rtc", 18, 0),
+	CLK_PERIPH(CLK_QSPI, "clk_periph_qspi", 19, 0),
+	CLK_PERIPH(CLK_GPIO0, "clk_periph_gpio0", 20, 0),
+	CLK_PERIPH(CLK_GPIO1, "clk_periph_gpio1", 21, 0),
+	CLK_PERIPH(CLK_GPIO2, "clk_periph_gpio2", 22, 0),
+	CLK_PERIPH(CLK_DDRC, "clk_periph_ddrc", 23, CLK_IS_CRITICAL),
+	CLK_PERIPH(CLK_FIC0, "clk_periph_fic0", 24, 0),
+	CLK_PERIPH(CLK_FIC1, "clk_periph_fic1", 25, 0),
+	CLK_PERIPH(CLK_FIC2, "clk_periph_fic2", 26, 0),
+	CLK_PERIPH(CLK_FIC3, "clk_periph_fic3", 27, 0),
+	CLK_PERIPH(CLK_ATHENA, "clk_periph_athena", 28, 0),
+	CLK_PERIPH(CLK_CFM, "clk_periph_cfm", 29, 0),
+};
+
+int mpfs_clk_register_periphs(void __iomem *base, u32 clk_rate,
+			      const char *parent_name)
+{
+	int ret;
+	int i, id, num_clks;
+	const char *name;
+	struct clk *hw;
+
+	num_clks = ARRAY_SIZE(mpfs_periph_clks);
+	for (i = 0; i < num_clks; i++)  {
+		hw = &mpfs_periph_clks[i].hw;
+		mpfs_periph_clks[i].sys_base = base;
+		mpfs_periph_clks[i].prate = clk_rate;
+		name = mpfs_periph_clks[i].periph.name;
+		ret = clk_register(hw, MPFS_PERIPH_CLOCK, name, parent_name);
+		if (ret)
+			ERR_PTR(ret);
+		id = mpfs_periph_clks[i].periph.id;
+		clk_dm(id, hw);
+	}
+
+	return 0;
+}
+
+const struct clk_ops mpfs_periph_clk_ops = {
+	.enable = mpfs_periph_clk_enable,
+	.disable = mpfs_periph_clk_disable,
+	.get_rate = mpfs_periph_clk_recalc_rate,
+};
+
+U_BOOT_DRIVER(mpfs_periph_clock) = {
+	.name	= MPFS_PERIPH_CLOCK,
+	.id	= UCLASS_CLK,
+	.ops	= &mpfs_periph_clk_ops,
+};

include/dt-bindings/clock/microchip-mpfs-clock.h

@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/*
+ * Copyright (C) 2020 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari@microchip.com>
+ */
+
+#ifndef _DT_BINDINGS_CLK_MICROCHIP_MPFS_H_
+#define _DT_BINDINGS_CLK_MICROCHIP_MPFS_H_
+
+#define CLK_CPU		0
+#define CLK_AXI		1
+#define CLK_AHB		2
+
+#define CLK_ENVM	3
+#define CLK_MAC0	4
+#define CLK_MAC1	5
+#define CLK_MMC		6
+#define CLK_TIMER	7
+#define CLK_MMUART0	8
+#define CLK_MMUART1	9
+#define CLK_MMUART2	10
+#define CLK_MMUART3	11
+#define CLK_MMUART4	12
+#define CLK_SPI0	13
+#define CLK_SPI1	14
+#define CLK_I2C0	15
+#define CLK_I2C1	16
+#define CLK_CAN0	17
+#define CLK_CAN1	18
+#define CLK_USB		19
+#define CLK_RESERVED	20
+#define CLK_RTC		21
+#define CLK_QSPI	22
+#define CLK_GPIO0	23
+#define CLK_GPIO1	24
+#define CLK_GPIO2	25
+#define CLK_DDRC	26
+#define CLK_FIC0	27
+#define CLK_FIC1	28
+#define CLK_FIC2	29
+#define CLK_FIC3	30
+#define CLK_ATHENA	31
+#define CLK_CFM		32
+
+#endif	/* _DT_BINDINGS_CLK_MICROCHIP_MPFS_H_ */