Thread (6 messages) 6 messages, 4 authors, 2021-08-29

Re: [PATCH v5 2/2] clk: microchip: Add driver for Microchip PolarFire SoC

From: Stephen Boyd <sboyd@kernel.org>
Date: 2021-08-29 18:21:09
Also in: linux-clk

Quoting daire.mcnamara@microchip.com (2021-05-28 06:43:08)
quoted hunk ↗ jump to hunk
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'.
quoted hunk ↗ jump to hunk
 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?
quoted hunk ↗ jump to hunk
+       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@microchip.com>
+ * 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");
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