[PATCH v1 2/2] CLK: microchip: Add driver for Microchip PolarFire SoC

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From: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>

    Add support for clock configuration on Microchip PolarFire SoC

    Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
---
 drivers/clk/Kconfig                           |   5 +
 drivers/clk/Makefile                          |   1 +
 drivers/clk/microchip/Makefile                |   1 +
 drivers/clk/microchip/clk-pfsoc.c             | 424 ++++++++++++++++++
 .../dt-bindings/clock/microchip,pfsoc-clock.h |  45 ++
 5 files changed, 476 insertions(+)
 create mode 100644 drivers/clk/microchip/clk-pfsoc.c
 create mode 100644 include/dt-bindings/clock/microchip,pfsoc-clock.h

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 4026fac9fac3..5ba96ba3028a 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -359,6 +359,11 @@ config COMMON_CLK_FIXED_MMIO
 	help
 	  Support for Memory Mapped IO Fixed clocks
 
+config MCHP_CLK_PFSOC
+        bool "Clk driver for PolarFire SoC"
+	help
+	  Supports Clock Configuration for PolarFire SoC
+
 source "drivers/clk/actions/Kconfig"
 source "drivers/clk/analogbits/Kconfig"
 source "drivers/clk/baikal-t1/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index da8fcf147eb1..a3d4ad288053 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_MACH_LOONGSON32)		+= loongson1/
 obj-y					+= mediatek/
 obj-$(CONFIG_ARCH_MESON)		+= meson/
 obj-$(CONFIG_MACH_PIC32)		+= microchip/
+obj-$(CONFIG_MCHP_CLK_PFSOC)	        += microchip/
 ifeq ($(CONFIG_COMMON_CLK), y)
 obj-$(CONFIG_ARCH_MMP)			+= mmp/
 endif
diff --git a/drivers/clk/microchip/Makefile b/drivers/clk/microchip/Makefile
index f34b247e870f..55156dd15596 100644
--- a/drivers/clk/microchip/Makefile
+++ b/drivers/clk/microchip/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_COMMON_CLK_PIC32) += clk-core.o
 obj-$(CONFIG_PIC32MZDA) += clk-pic32mzda.o
+obj-$(CONFIG_MCHP_CLK_PFSOC) += clk-pfsoc.o
diff --git a/drivers/clk/microchip/clk-pfsoc.c b/drivers/clk/microchip/clk-pfsoc.c
new file mode 100644
index 000000000000..affd023ef084
--- /dev/null
+++ b/drivers/clk/microchip/clk-pfsoc.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Daire McNamara,<daire.mcnamara@xxxxxxxxxxxxx>
+ * Copyright (C) 2020 Microchip Technology Inc.  All rights reserved.
+ */
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <dt-bindings/clock/microchip,pfsoc-clock.h>
+
+/* address offset of control registers */
+#define REG_CLOCK_CONFIG_CR	0x08u
+#define REG_SUBBLK_CLOCK_CR	0x84u
+#define REG_SUBBLK_RESET_CR	0x88u
+
+/*
+ * pfsoc_clk_lock prevents anything else from writing to the
+ * pfsoc clk block while a software locked register is being written.
+ */
+static DEFINE_SPINLOCK(pfsoc_clk_lock);
+
+static struct clk_parent_data pfsoc_cfg_parent[] = {
+	{ .fw_name = "msspllclk", .name = "msspllclk" },
+};
+
+struct pfsoc_clock_data {
+	void __iomem *reg;
+	struct clk_hw_onecell_data hw_data;
+};
+
+static const struct clk_div_table pfsoc_div_cpu_axi_table[] = {
+	{ 0, 1 }, { 1, 2 }, { 2, 4 }, { 3, 8 },
+	{ 0, 0 }
+};
+
+static const struct clk_div_table pfsoc_div_ahb_table[] = {
+	{ 1, 2 }, { 2, 4}, { 3, 8 },
+	{ 0, 0 }
+};
+
+struct pfsoc_cfg_clock {
+	unsigned int id;
+	const char *name;
+	u8 shift;
+	u8 width;
+	const struct clk_div_table *table;
+	unsigned long flags;
+};
+
+struct pfsoc_cfg_hw_clock {
+	struct pfsoc_cfg_clock cfg;
+	void __iomem *sys_base;
+	/* lock is used to prevent multiple writes */
+	spinlock_t *lock;
+	struct clk_hw hw;
+	struct clk_init_data init;
+};
+
+#define to_pfsoc_cfg_clk(_hw) container_of(_hw, struct pfsoc_cfg_hw_clock, hw)
+
+static unsigned long pfsoc_cfg_clk_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+	struct pfsoc_cfg_hw_clock *cfg_hw = to_pfsoc_cfg_clk(hw);
+	struct pfsoc_cfg_clock *cfg = &cfg_hw->cfg;
+	void __iomem *base_addr = cfg_hw->sys_base;
+	unsigned long rate;
+	u32 val;
+
+	val = readl_relaxed(base_addr + REG_CLOCK_CONFIG_CR) >> cfg->shift;
+	val &= clk_div_mask(cfg->width);
+	rate = prate / (1u << val);
+
+	return rate;
+}
+
+static long pfsoc_cfg_clk_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
+{
+	struct pfsoc_cfg_hw_clock *cfg_hw = to_pfsoc_cfg_clk(hw);
+	struct pfsoc_cfg_clock *cfg = &cfg_hw->cfg;
+
+	return divider_round_rate(hw, rate, prate, cfg->table, cfg->width, cfg->flags);
+}
+
+static int pfsoc_cfg_clk_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
+{
+	struct pfsoc_cfg_hw_clock *cfg_hw = to_pfsoc_cfg_clk(hw);
+	struct pfsoc_cfg_clock *cfg = &cfg_hw->cfg;
+	void __iomem *base_addr = cfg_hw->sys_base;
+	unsigned long flags = 0;
+	u32 divider_setting, val;
+
+	divider_setting = divider_get_val(rate, prate, cfg->table, cfg->width, cfg_hw->cfg.flags);
+
+	if (divider_setting < 0)
+		return divider_setting;
+
+	if (cfg_hw->lock)
+		spin_lock_irqsave(cfg_hw->lock, flags);
+	else
+		__acquire(cfg_hw->lock);
+
+	val = readl_relaxed(base_addr + REG_CLOCK_CONFIG_CR);
+	val &= ~(clk_div_mask(cfg->width) << cfg_hw->cfg.shift);
+	val |= divider_setting << cfg->shift;
+	writel_relaxed(val, base_addr + REG_CLOCK_CONFIG_CR);
+
+	if (cfg_hw->lock)
+		spin_unlock_irqrestore(cfg_hw->lock, flags);
+	else
+		__release(cfg_hw->lock);
+
+	return 0;
+}
+
+static const struct clk_ops pfsoc_clk_cfg_ops = {
+	.recalc_rate = pfsoc_cfg_clk_recalc_rate,
+	.round_rate = pfsoc_cfg_clk_round_rate,
+	.set_rate = pfsoc_cfg_clk_set_rate,
+};
+
+#define CLK_CFG(_id, _name, _parent, _shift, _width, _table, _flags) {	\
+		.cfg.id = _id,								\
+		.cfg.name = _name,							\
+		.cfg.shift = _shift,							\
+		.cfg.width = _width,							\
+		.cfg.table = _table,							\
+		.hw.init = CLK_HW_INIT_PARENTS_DATA(_name, _parent, &pfsoc_clk_cfg_ops,	\
+						    _flags),				\
+	}
+
+static struct pfsoc_cfg_hw_clock pfsoc_cfg_clks[] = {
+	CLK_CFG(CLK_CPU, "clk_cpu", pfsoc_cfg_parent, 0, 2, pfsoc_div_cpu_axi_table, 0),
+	CLK_CFG(CLK_AXI, "clk_axi", pfsoc_cfg_parent, 2, 2, pfsoc_div_cpu_axi_table, 0),
+	CLK_CFG(CLK_AHB, "clk_ahb", pfsoc_cfg_parent, 4, 2, pfsoc_div_ahb_table, 0),
+};
+
+#define CPU_PARENT pfsoc_cfg_clks[0].hw
+#define AXI_PARENT pfsoc_cfg_clks[1].hw
+#define AHB_PARENT pfsoc_cfg_clks[2].hw
+
+static void pfsoc_clk_unregister_cfg(struct device *dev, struct clk_hw *hw)
+{
+	struct pfsoc_cfg_hw_clock *cfg_hw = to_pfsoc_cfg_clk(hw);
+
+	devm_clk_hw_unregister(dev, hw);
+	kfree(cfg_hw);
+}
+
+static struct clk_hw *pfsoc_clk_register_cfg(struct device *dev,
+					     struct pfsoc_cfg_hw_clock *cfg_hw,
+					     void __iomem *sys_base)
+{
+	struct clk_hw *hw;
+	int err;
+
+	cfg_hw->sys_base = sys_base;
+	cfg_hw->lock = &pfsoc_clk_lock;
+
+	hw = &cfg_hw->hw;
+	err = devm_clk_hw_register(dev, hw);
+	if (err)
+		return ERR_PTR(err);
+
+	return hw;
+}
+
+static int pfsoc_clk_register_cfgs(struct device *dev, struct pfsoc_cfg_hw_clock *cfg_hws,
+				   int num_clks, struct pfsoc_clock_data *data)
+{
+	struct clk_hw *hw;
+	void __iomem *sys_base = data->reg;
+	unsigned int i, id;
+
+	for (i = 0; i < num_clks; i++) {
+		struct pfsoc_cfg_hw_clock *cfg_hw = &cfg_hws[i];
+
+		hw = pfsoc_clk_register_cfg(dev, cfg_hw, sys_base);
+		if (IS_ERR(hw)) {
+			pr_err("%s: failed to register clock %s\n", __func__,
+			       cfg_hw->cfg.name);
+			goto err_clk;
+		}
+
+		id = cfg_hws[i].cfg.id;
+		data->hw_data.hws[id] = hw;
+	}
+
+	return 0;
+
+err_clk:
+	while (i--)
+		pfsoc_clk_unregister_cfg(dev, data->hw_data.hws[cfg_hws[i].cfg.id]);
+
+	return PTR_ERR(hw);
+}
+
+struct pfsoc_periph_clock {
+	unsigned int id;
+	const char *name;
+	u8 shift;
+	unsigned long flags;
+};
+
+struct pfsoc_periph_hw_clock {
+	struct pfsoc_periph_clock periph;
+	void __iomem *sys_base;
+	/* lock is used to prevent multiple writes */
+	spinlock_t *lock;
+	struct clk_hw hw;
+};
+
+#define to_pfsoc_periph_clk(_hw) container_of(_hw, struct pfsoc_periph_hw_clock, hw)
+
+static int pfsoc_periph_clk_enable(struct clk_hw *hw)
+{
+	struct pfsoc_periph_hw_clock *periph_hw = to_pfsoc_periph_clk(hw);
+	struct pfsoc_periph_clock *periph = &periph_hw->periph;
+	void __iomem *base_addr = periph_hw->sys_base;
+	u32 reg, val;
+
+	reg = readl_relaxed(base_addr + REG_SUBBLK_RESET_CR);
+	val = reg & ~(1u << periph->shift);
+	writel_relaxed(val, base_addr + REG_SUBBLK_RESET_CR);
+
+	reg = readl_relaxed(base_addr + REG_SUBBLK_CLOCK_CR);
+	val = reg | (1u << periph->shift);
+	writel_relaxed(val, base_addr + REG_SUBBLK_CLOCK_CR);
+
+	return 0;
+}
+
+static void pfsoc_periph_clk_disable(struct clk_hw *hw)
+{
+	struct pfsoc_periph_hw_clock *periph_hw = to_pfsoc_periph_clk(hw);
+	struct pfsoc_periph_clock *periph = &periph_hw->periph;
+	void __iomem *base_addr = periph_hw->sys_base;
+	u32 reg, val;
+
+	reg = readl_relaxed(base_addr + REG_SUBBLK_RESET_CR);
+	val = reg | (1u << periph->shift);
+	writel_relaxed(val, base_addr + REG_SUBBLK_RESET_CR);
+
+	reg = readl_relaxed(base_addr + REG_SUBBLK_CLOCK_CR);
+	val = reg & ~(1u << periph->shift);
+	writel_relaxed(val, base_addr + REG_SUBBLK_CLOCK_CR);
+}
+
+static int pfsoc_periph_clk_is_enabled(struct clk_hw *hw)
+{
+	struct pfsoc_periph_hw_clock *periph_hw = to_pfsoc_periph_clk(hw);
+	struct pfsoc_periph_clock *periph = &periph_hw->periph;
+	void __iomem *base_addr = periph_hw->sys_base;
+	u32 reg;
+
+	reg = readl_relaxed(base_addr + REG_SUBBLK_RESET_CR);
+	if ((reg & (1u << periph->shift)) == 0u) {
+		reg = readl_relaxed(base_addr + REG_SUBBLK_CLOCK_CR);
+		if (reg & (1u << periph->shift))
+			return 1;
+	}
+
+	return 0;
+}
+
+static unsigned long pfsoc_periph_clk_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+	return prate;
+}
+
+static const struct clk_ops pfsoc_periph_clk_ops = {
+	.enable = pfsoc_periph_clk_enable,
+	.disable = pfsoc_periph_clk_disable,
+	.is_enabled = pfsoc_periph_clk_is_enabled,
+	.recalc_rate = pfsoc_periph_clk_recalc_rate,
+};
+
+#define CLK_PERIPH(_id, _name, _parent, _shift, _flags) {			\
+		.periph.id = _id,							\
+		.periph.name = _name,							\
+		.periph.shift = _shift,							\
+		.hw.init = CLK_HW_INIT_HW(_name, _parent, &pfsoc_periph_clk_ops,	\
+					  _flags),					\
+	}
+
+static struct pfsoc_periph_hw_clock pfsoc_periph_clks[] = {
+	CLK_PERIPH(CLK_ENVM, "clk_periph_envm", &AHB_PARENT, 0, CLK_IS_CRITICAL),
+	CLK_PERIPH(CLK_MAC0, "clk_periph_mac0", &AHB_PARENT, 1, 0),
+	CLK_PERIPH(CLK_MAC1, "clk_periph_mac1", &AHB_PARENT, 2, 0),
+	CLK_PERIPH(CLK_MMC, "clk_periph_mmc", &AHB_PARENT, 3, 0),
+	CLK_PERIPH(CLK_TIMER, "clk_periph_timer", &AHB_PARENT, 4, 0),
+	CLK_PERIPH(CLK_MMUART0, "clk_periph_mmuart0", &AHB_PARENT, 5, 0),
+	CLK_PERIPH(CLK_MMUART1, "clk_periph_mmuart1", &AHB_PARENT, 6, 0),
+	CLK_PERIPH(CLK_MMUART2, "clk_periph_mmuart2", &AHB_PARENT, 7, 0),
+	CLK_PERIPH(CLK_MMUART3, "clk_periph_mmuart3", &AHB_PARENT, 8, 0),
+	CLK_PERIPH(CLK_MMUART4, "clk_periph_mmuart4", &AHB_PARENT, 9, 0),
+	CLK_PERIPH(CLK_SPI0, "clk_periph_spi0", &AHB_PARENT, 10, 0),
+	CLK_PERIPH(CLK_SPI1, "clk_periph_spi1", &AHB_PARENT, 11, 0),
+	CLK_PERIPH(CLK_I2C0, "clk_periph_i2c0", &AHB_PARENT, 12, 0),
+	CLK_PERIPH(CLK_I2C1, "clk_periph_i2c1", &AHB_PARENT, 13, 0),
+	CLK_PERIPH(CLK_CAN0, "clk_periph_can0", &AHB_PARENT, 14, 0),
+	CLK_PERIPH(CLK_CAN1, "clk_periph_can1", &AHB_PARENT, 15, 0),
+	CLK_PERIPH(CLK_USB, "clk_periph_usb", &AHB_PARENT, 16, 0),
+	CLK_PERIPH(CLK_RTC, "clk_periph_rtc", &AHB_PARENT, 18, 0),
+	CLK_PERIPH(CLK_QSPI, "clk_periph_qspi", &AHB_PARENT, 19, 0),
+	CLK_PERIPH(CLK_GPIO0, "clk_periph_gpio0", &AHB_PARENT, 20, 0),
+	CLK_PERIPH(CLK_GPIO1, "clk_periph_gpio1", &AHB_PARENT, 21, 0),
+	CLK_PERIPH(CLK_GPIO2, "clk_periph_gpio2", &AHB_PARENT, 22, 0),
+	CLK_PERIPH(CLK_DDRC, "clk_periph_ddrc", &AHB_PARENT, 23, CLK_IS_CRITICAL),
+	CLK_PERIPH(CLK_FIC0, "clk_periph_fic0", &AHB_PARENT, 24, 0),
+	CLK_PERIPH(CLK_FIC1, "clk_periph_fic1", &AHB_PARENT, 25, 0),
+	CLK_PERIPH(CLK_FIC2, "clk_periph_fic2", &AHB_PARENT, 26, 0),
+	CLK_PERIPH(CLK_FIC3, "clk_periph_fic3", &AHB_PARENT, 27, 0),
+	CLK_PERIPH(CLK_ATHENA, "clk_periph_athena", &AHB_PARENT, 28, 0),
+	CLK_PERIPH(CLK_CFM, "clk_periph_cfm", &AHB_PARENT, 29, 0),
+};
+
+static void pfsoc_clk_unregister_periph(struct device *dev, struct clk_hw *hw)
+{
+	struct pfsoc_periph_hw_clock *periph_hw = to_pfsoc_periph_clk(hw);
+
+	devm_clk_hw_unregister(dev, hw);
+	kfree(periph_hw);
+}
+
+static struct clk_hw *pfsoc_clk_register_periph(struct device *dev,
+						struct pfsoc_periph_hw_clock *periph_hw,
+						void __iomem *sys_base)
+{
+	struct clk_hw *hw;
+	int err;
+
+	periph_hw->sys_base = sys_base;
+	periph_hw->lock = &pfsoc_clk_lock;
+
+	hw = &periph_hw->hw;
+	err = devm_clk_hw_register(dev, hw);
+	if (err)
+		return ERR_PTR(err);
+
+	return hw;
+}
+
+static int pfsoc_clk_register_periphs(struct device *dev, struct pfsoc_periph_hw_clock *periph_hws,
+				      int num_clks, struct pfsoc_clock_data *data)
+{
+	struct clk_hw *hw;
+	void __iomem *sys_base = data->reg;
+	unsigned int i, id;
+
+	for (i = 0; i < num_clks; i++) {
+		struct pfsoc_periph_hw_clock *periph_hw = &periph_hws[i];
+
+		hw = pfsoc_clk_register_periph(dev, periph_hw, sys_base);
+		if (IS_ERR(hw)) {
+			pr_err("%s: failed to register clock %s\n", __func__,
+			       periph_hw->periph.name);
+			goto err_clk;
+		}
+
+		id = periph_hws[i].periph.id;
+		data->hw_data.hws[id] = hw;
+	}
+
+	return 0;
+
+err_clk:
+	while (i--)
+		pfsoc_clk_unregister_periph(dev, data->hw_data.hws[periph_hws[i].periph.id]);
+
+	return PTR_ERR(hw);
+}
+
+static int pfsoc_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct pfsoc_clock_data *clk_data;
+	struct resource *res;
+	int num_clks;
+	int ret;
+
+	num_clks = ARRAY_SIZE(pfsoc_cfg_clks) + ARRAY_SIZE(pfsoc_periph_clks);
+
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hw_data.hws, num_clks), GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	clk_data->reg = devm_ioremap_resource(dev, res);
+
+	clk_data->hw_data.num = num_clks;
+
+	pfsoc_clk_register_cfgs(dev, pfsoc_cfg_clks, ARRAY_SIZE(pfsoc_cfg_clks), clk_data);
+
+	pfsoc_clk_register_periphs(dev, pfsoc_periph_clks, ARRAY_SIZE(pfsoc_periph_clks), clk_data);
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, &clk_data->hw_data);
+
+	if (ret == 0)
+		dev_info(dev, "registered PFSOC core clocks\n");
+	else
+		dev_err(dev, "failed to register PFSOC core clocks\n");
+
+	return ret;
+}
+
+static const struct of_device_id pfsoc_of_match[] = {
+	{ .compatible = "microchip,pfsoc-clkcfg", },
+	{}
+};
+
+static struct platform_driver pfsoc_clk_driver = {
+	.probe = pfsoc_clk_probe,
+	.driver	= {
+		.name = "microchip-pfsoc-clkcfg",
+		.of_match_table = pfsoc_of_match,
+	},
+};
+
+static int __init clk_pfsoc_init(void)
+{
+	return platform_driver_register(&pfsoc_clk_driver);
+}
+core_initcall(clk_pfsoc_init);
diff --git a/include/dt-bindings/clock/microchip,pfsoc-clock.h b/include/dt-bindings/clock/microchip,pfsoc-clock.h
new file mode 100644
index 000000000000..c9d8e4f6b963
--- /dev/null
+++ b/include/dt-bindings/clock/microchip,pfsoc-clock.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Daire McNamara,<daire.mcnamara@xxxxxxxxxxxxx>
+ * Copyright (C) 2020 Microchip Technology Inc.  All rights reserved.
+ */
+
+#ifndef _DT_BINDINGS_CLK_MICROCHIP_PFSOC_H_
+#define _DT_BINDINGS_CLK_MICROCHIP_PFSOC_H_
+
+#define CLK_CPU		0
+#define CLK_AXI		1
+#define CLK_AHB		2
+
+#define CLK_ENVM	0
+#define CLK_MAC0	1
+#define CLK_MAC1	2
+#define CLK_MMC		3
+#define CLK_TIMER	4
+#define CLK_MMUART0	5
+#define CLK_MMUART1	6
+#define CLK_MMUART2	7
+#define CLK_MMUART3	8
+#define CLK_MMUART4	9
+#define CLK_SPI0	10
+#define CLK_SPI1	11
+#define CLK_I2C0	12
+#define CLK_I2C1	13
+#define CLK_CAN0	14
+#define CLK_CAN1	15
+#define CLK_USB		16
+#define CLK_RESERVED	17
+#define CLK_RTC		18
+#define CLK_QSPI	19
+#define CLK_GPIO0	20
+#define CLK_GPIO1	21
+#define CLK_GPIO2	22
+#define CLK_DDRC	23
+#define CLK_FIC0	24
+#define CLK_FIC1	25
+#define CLK_FIC2	26
+#define CLK_FIC3	27
+#define CLK_ATHENA	28
+#define CLK_CFM		29
+
+#endif	/* _DT_BINDINGS_CLK_MICROCHIP_PFSOC_H_ */
-- 
2.25.1




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