Quoting daire.mcnamara@xxxxxxxxxxxxx (2021-05-28 06:43:08)
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index a588d56502d4..ab604dd02acf 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -388,6 +388,7 @@ source "drivers/clk/keystone/Kconfig"
> source "drivers/clk/mediatek/Kconfig"
> source "drivers/clk/meson/Kconfig"
> source "drivers/clk/mstar/Kconfig"
> +source "drivers/clk/microchip/Kconfig"
'i' comes before 's'.
> source "drivers/clk/mvebu/Kconfig"
> source "drivers/clk/qcom/Kconfig"
> source "drivers/clk/renesas/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index b22ae4f81e0b..fb87a18ae8ec 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -89,7 +89,7 @@ obj-$(CONFIG_ARCH_KEYSTONE) += keystone/
> obj-$(CONFIG_MACH_LOONGSON32) += loongson1/
> obj-y += mediatek/
> obj-$(CONFIG_ARCH_MESON) += meson/
> -obj-$(CONFIG_MACH_PIC32) += microchip/
> +obj-y += microchip/
> ifeq ($(CONFIG_COMMON_CLK), y)
> obj-$(CONFIG_ARCH_MMP) += mmp/
> endif
> diff --git a/drivers/clk/microchip/Kconfig b/drivers/clk/microchip/Kconfig
> new file mode 100644
> index 000000000000..f5edc7b3c07c
> --- /dev/null
> +++ b/drivers/clk/microchip/Kconfig
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +config MCHP_CLK_MPFS
> + bool "Clk driver for PolarFire SoC"
> + depends on (RISCV && SOC_MICROCHIP_POLARFIRE) || COMPILE_TEST
Should also have
default CONFIG_MACH_PIC32
here to keep things working for olddefconfig?
> + help
> + Supports Clock Configuration for PolarFire SoC
> diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
> new file mode 100644
> index 000000000000..541f88181877
> --- /dev/null
> +++ b/drivers/clk/microchip/clk-mpfs.c
> @@ -0,0 +1,444 @@
> +// 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/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <dt-bindings/clock/microchip,mpfs-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
> +
> +struct mpfs_clock_data {
> + void __iomem *base;
> + struct clk_hw_onecell_data hw_data;
> +};
> +
> +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 {
> + struct mpfs_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_mpfs_cfg_clk(_hw) container_of(_hw, struct mpfs_cfg_hw_clock, hw)
> +
> +struct mpfs_periph_clock {
> + unsigned int id;
> + const char *name;
> + u8 shift;
> + unsigned long flags;
> +};
> +
> +struct mpfs_periph_hw_clock {
> + struct mpfs_periph_clock periph;
> + void __iomem *sys_base;
> + /* lock is used to prevent multiple writes */
> + spinlock_t *lock;
> + struct clk_hw hw;
> +};
> +
> +#define to_mpfs_periph_clk(_hw) container_of(_hw, struct mpfs_periph_hw_clock, hw)
> +
> +/*
> + * mpfs_clk_lock prevents anything else from writing to the
> + * mpfs clk block while a software locked register is being written.
> + */
> +static DEFINE_SPINLOCK(mpfs_clk_lock);
> +
> +static struct clk_parent_data mpfs_cfg_parent[] = {
> + { .fw_name = "msspllclk", .name = "msspllclk" },
> +};
> +
> +static const struct clk_div_table mpfs_div_cpu_axi_table[] = {
> + { 0, 1 }, { 1, 2 }, { 2, 4 }, { 3, 8 },
Is this 1 << val? Do we need a table for that?
> + { 0, 0 }
> +};
> +
> +static const struct clk_div_table mpfs_div_ahb_table[] = {
> + { 1, 2 }, { 2, 4}, { 3, 8 },
> + { 0, 0 }
> +};
> +
> +static unsigned long mpfs_cfg_clk_recalc_rate(struct clk_hw *hw, unsigned long prate)
> +{
> + 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_relaxed(base_addr + REG_CLOCK_CONFIG_CR) >> cfg->shift;
> + val &= clk_div_mask(cfg->width);
> + rate = prate / (1u << val);
> +
> + return rate;
return prate / (1u << val);
> +}
> +
> +static long mpfs_cfg_clk_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
> +{
> + struct mpfs_cfg_hw_clock *cfg_hw = to_mpfs_cfg_clk(hw);
> + struct mpfs_cfg_clock *cfg = &cfg_hw->cfg;
> +
> + return divider_round_rate(hw, rate, prate, cfg->table, cfg->width, cfg->flags);
> +}
> +
> +static int mpfs_cfg_clk_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
> +{
> + 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 flags = 0;
Do we need to initialize flags?
> + u32 val;
> + int divider_setting;
> +
> + 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)
Does it need to be conditional?
> + 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 mpfs_clk_cfg_ops = {
> + .recalc_rate = mpfs_cfg_clk_recalc_rate,
> + .round_rate = mpfs_cfg_clk_round_rate,
> + .set_rate = mpfs_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, &mpfs_clk_cfg_ops, \
> + _flags), \
> + }
> +
> +static struct mpfs_cfg_hw_clock mpfs_cfg_clks[] = {
> + CLK_CFG(CLK_CPU, "clk_cpu", mpfs_cfg_parent, 0, 2, mpfs_div_cpu_axi_table, 0),
> + CLK_CFG(CLK_AXI, "clk_axi", mpfs_cfg_parent, 2, 2, mpfs_div_cpu_axi_table, 0),
> + CLK_CFG(CLK_AHB, "clk_ahb", mpfs_cfg_parent, 4, 2, mpfs_div_ahb_table, 0),
> +};
> +
> +static void mpfs_clk_unregister_cfg(struct device *dev, struct clk_hw *hw)
> +{
> + struct mpfs_cfg_hw_clock *cfg_hw = to_mpfs_cfg_clk(hw);
> +
> + devm_clk_hw_unregister(dev, hw);
> + kfree(cfg_hw);
> +}
> +
> +static struct clk_hw *mpfs_clk_register_cfg(struct device *dev,
> + struct mpfs_cfg_hw_clock *cfg_hw,
> + void __iomem *sys_base)
> +{
> + struct clk_hw *hw;
> + int err;
> +
> + cfg_hw->sys_base = sys_base;
> + cfg_hw->lock = &mpfs_clk_lock;
> +
> + hw = &cfg_hw->hw;
> + err = devm_clk_hw_register(dev, hw);
> + if (err)
> + return ERR_PTR(err);
> +
> + return hw;
> +}
> +
> +static int mpfs_clk_register_cfgs(struct device *dev, struct mpfs_cfg_hw_clock *cfg_hws,
> + int num_clks, struct mpfs_clock_data *data)
> +{
> + struct clk_hw *hw;
> + void __iomem *sys_base = data->base;
> + unsigned int i, id;
> +
> + for (i = 0; i < num_clks; i++) {
> + struct mpfs_cfg_hw_clock *cfg_hw = &cfg_hws[i];
> +
> + hw = mpfs_clk_register_cfg(dev, cfg_hw, sys_base);
> + if (IS_ERR(hw)) {
> + dev_err(dev, "%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--)
> + mpfs_clk_unregister_cfg(dev, data->hw_data.hws[cfg_hws[i].cfg.id]);
> +
> + return PTR_ERR(hw);
> +}
> +
> +static int mpfs_periph_clk_enable(struct clk_hw *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;
> +
> + 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 mpfs_periph_clk_disable(struct clk_hw *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;
> +
> + 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 mpfs_periph_clk_is_enabled(struct clk_hw *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;
> +
> + 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 mpfs_periph_clk_recalc_rate(struct clk_hw *hw, unsigned long prate)
> +{
> + return prate;
> +}
This is the default implementation, so it can be dropped.
> +
> +static const struct clk_ops mpfs_periph_clk_ops = {
> + .enable = mpfs_periph_clk_enable,
> + .disable = mpfs_periph_clk_disable,
> + .is_enabled = mpfs_periph_clk_is_enabled,
> + .recalc_rate = mpfs_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, &mpfs_periph_clk_ops, \
> + _flags), \
> + }
> +
> +#define PARENT_CLK(PARENT) (&mpfs_cfg_clks[CLK_##PARENT].hw)
> +
> +static struct mpfs_periph_hw_clock mpfs_periph_clks[] = {
> + CLK_PERIPH(CLK_ENVM, "clk_periph_envm", PARENT_CLK(AHB), 0, CLK_IS_CRITICAL),
Please add a comment explaining why it is critical. That way we know
what to do with the clk in the future.
> + CLK_PERIPH(CLK_MAC0, "clk_periph_mac0", PARENT_CLK(AHB), 1, 0),
> + CLK_PERIPH(CLK_MAC1, "clk_periph_mac1", PARENT_CLK(AHB), 2, 0),
> + CLK_PERIPH(CLK_MMC, "clk_periph_mmc", PARENT_CLK(AHB), 3, 0),
> + CLK_PERIPH(CLK_TIMER, "clk_periph_timer", PARENT_CLK(AHB), 4, 0),
> + CLK_PERIPH(CLK_MMUART0, "clk_periph_mmuart0", PARENT_CLK(AHB), 5, CLK_IS_CRITICAL),
> + CLK_PERIPH(CLK_MMUART1, "clk_periph_mmuart1", PARENT_CLK(AHB), 6, 0),
> + CLK_PERIPH(CLK_MMUART2, "clk_periph_mmuart2", PARENT_CLK(AHB), 7, 0),
> + CLK_PERIPH(CLK_MMUART3, "clk_periph_mmuart3", PARENT_CLK(AHB), 8, 0),
> + CLK_PERIPH(CLK_MMUART4, "clk_periph_mmuart4", PARENT_CLK(AHB), 9, 0),
> + CLK_PERIPH(CLK_SPI0, "clk_periph_spi0", PARENT_CLK(AHB), 10, 0),
> + CLK_PERIPH(CLK_SPI1, "clk_periph_spi1", PARENT_CLK(AHB), 11, 0),
> + CLK_PERIPH(CLK_I2C0, "clk_periph_i2c0", PARENT_CLK(AHB), 12, 0),
> + CLK_PERIPH(CLK_I2C1, "clk_periph_i2c1", PARENT_CLK(AHB), 13, 0),
> + CLK_PERIPH(CLK_CAN0, "clk_periph_can0", PARENT_CLK(AHB), 14, 0),
> + CLK_PERIPH(CLK_CAN1, "clk_periph_can1", PARENT_CLK(AHB), 15, 0),
> + CLK_PERIPH(CLK_USB, "clk_periph_usb", PARENT_CLK(AHB), 16, 0),
> + CLK_PERIPH(CLK_RTC, "clk_periph_rtc", PARENT_CLK(AHB), 18, 0),
> + CLK_PERIPH(CLK_QSPI, "clk_periph_qspi", PARENT_CLK(AHB), 19, 0),
> + CLK_PERIPH(CLK_GPIO0, "clk_periph_gpio0", PARENT_CLK(AHB), 20, 0),
> + CLK_PERIPH(CLK_GPIO1, "clk_periph_gpio1", PARENT_CLK(AHB), 21, 0),
> + CLK_PERIPH(CLK_GPIO2, "clk_periph_gpio2", PARENT_CLK(AHB), 22, 0),
> + CLK_PERIPH(CLK_DDRC, "clk_periph_ddrc", PARENT_CLK(AHB), 23, CLK_IS_CRITICAL),
> + CLK_PERIPH(CLK_FIC0, "clk_periph_fic0", PARENT_CLK(AHB), 24, 0),
> + CLK_PERIPH(CLK_FIC1, "clk_periph_fic1", PARENT_CLK(AHB), 25, 0),
> + CLK_PERIPH(CLK_FIC2, "clk_periph_fic2", PARENT_CLK(AHB), 26, 0),
> + CLK_PERIPH(CLK_FIC3, "clk_periph_fic3", PARENT_CLK(AHB), 27, 0),
> + CLK_PERIPH(CLK_ATHENA, "clk_periph_athena", PARENT_CLK(AHB), 28, 0),
> + CLK_PERIPH(CLK_CFM, "clk_periph_cfm", PARENT_CLK(AHB), 29, 0),
> +};
> +
> +static void mpfs_clk_unregister_periph(struct device *dev, struct clk_hw *hw)
> +{
> + struct mpfs_periph_hw_clock *periph_hw = to_mpfs_periph_clk(hw);
> +
> + devm_clk_hw_unregister(dev, hw);
> + kfree(periph_hw);
> +}
> +
> +static struct clk_hw *mpfs_clk_register_periph(struct device *dev,
> + struct mpfs_periph_hw_clock *periph_hw,
> + void __iomem *sys_base)
> +{
> + struct clk_hw *hw;
> + int err;
> +
> + periph_hw->sys_base = sys_base;
> + periph_hw->lock = &mpfs_clk_lock;
> +
> + hw = &periph_hw->hw;
> + err = devm_clk_hw_register(dev, hw);
> + if (err)
> + return ERR_PTR(err);
> +
> + return hw;
> +}
> +
> +static int mpfs_clk_register_periphs(struct device *dev, struct mpfs_periph_hw_clock *periph_hws,
> + int num_clks, struct mpfs_clock_data *data)
> +{
> + struct clk_hw *hw;
> + void __iomem *sys_base = data->base;
> + unsigned int i, id;
> +
> + for (i = 0; i < num_clks; i++) {
> + struct mpfs_periph_hw_clock *periph_hw = &periph_hws[i];
> +
> + hw = mpfs_clk_register_periph(dev, periph_hw, sys_base);
> + if (IS_ERR(hw)) {
> + dev_err(dev, "%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--)
> + mpfs_clk_unregister_periph(dev, data->hw_data.hws[periph_hws[i].periph.id]);
> +
> + return PTR_ERR(hw);
> +}
> +
> +static int mpfs_clk_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct mpfs_clock_data *clk_data;
> + struct resource *res;
> + int num_clks;
> + int ret;
> +
> + num_clks = ARRAY_SIZE(mpfs_cfg_clks) + ARRAY_SIZE(mpfs_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->base = devm_ioremap_resource(dev, res);
Use devm_platform_ioremap_resource()?
> + if (IS_ERR(clk_data->base))
> + return PTR_ERR(clk_data->base);
> +
> + clk_data->hw_data.num = num_clks;
> +
> + ret = mpfs_clk_register_cfgs(dev, mpfs_cfg_clks, ARRAY_SIZE(mpfs_cfg_clks), clk_data);
> + if (ret)
> + goto err_clk;
> +
> + ret = mpfs_clk_register_periphs(dev, mpfs_periph_clks, ARRAY_SIZE(mpfs_periph_clks),
> + clk_data);
> + if (ret)
> + goto err_clk;
> +
> + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, &clk_data->hw_data);
> + if (ret)
> + goto err_clk;
> +
> + dev_info(dev, "registered MPFS core clocks\n");
Please no "I'm probed" messages. The driver core already has these
things.
> + return ret;
> +
> +err_clk:
> + dev_err(dev, "failed to register MPFS core clocks\n");
> + return ret;
> +}
> +
> +static const struct of_device_id mpfs_clk_of_match_table[] = {
> + { .compatible = "microchip,mpfs-clkcfg", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, mpfs_clk_match_table);
> +
> +static struct platform_driver mpfs_clk_driver = {
> + .probe = mpfs_clk_probe,
> + .driver = {
> + .name = "microchip-mpfs-clkcfg",
> + .of_match_table = mpfs_clk_of_match_table,
> + },
> +};
> +
> +static int __init clk_mpfs_init(void)
> +{
> + return platform_driver_register(&mpfs_clk_driver);
> +}
> +core_initcall(clk_mpfs_init);
> +
> +static void __exit clk_mpfs_exit(void)
> +{
> + platform_driver_unregister(&mpfs_clk_driver);
> +}
> +module_exit(clk_mpfs_exit);
> +
> +MODULE_DESCRIPTION("Microchip PolarFire SoC Clock Driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:clk-mpfs");
