[PATCH v4 07/12] clk: en7523: Add clock driver for Airoha EN7523 SoC

Felix Fietkau
2021-11-25T11:10:05Z

This driver only registers fixed rate clocks, since the clocks are fully
initialized by the boot loader and should not be changed later, according
to Airoha.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
arch/arm/boot/dts/en7523.dtsi | 8 +
drivers/clk/Kconfig | 9 +
drivers/clk/Makefile | 1 +
drivers/clk/clk-en7523.c | 356 ++++++++++++++++++++++++++++++++++
4 files changed, 374 insertions(+)
create mode 100644 drivers/clk/clk-en7523.c

diff --git a/arch/arm/boot/dts/en7523.dtsi b/arch/arm/boot/dts/en7523.dtsi
index de9e5f3ff155..eabf3fdb3d52 100644
--- a/arch/arm/boot/dts/en7523.dtsi
+++ b/arch/arm/boot/dts/en7523.dtsi
@@ -2,6 +2,7 @@

#include <dt-bindings/interrupt-controller/irq.h>
#include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/clock/en7523-clk.h>

/ {
interrupt-parent = <&gic>;
@@ -82,6 +83,13 @@ L2_0: l2-cache0 {
};
};

+ scu: scu@1fa20000 {
+ compatible = "airoha,en7523-scu";
+ reg = <0x1fa20000 0x400>,
+ <0x1fb00000 0x1000>;
+ #clock-cells = <1>;
+ };
+
gic: interrupt-controller@9000000 {
compatible = "arm,gic-v3";
interrupt-controller;
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index c5b3dc97396a..b542f58c58d2 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -192,6 +192,15 @@ config COMMON_CLK_CS2000_CP
help
If you say yes here you get support for the CS2000 clock multiplier.

+config COMMON_CLK_EN7523
+ bool "Clock driver for Airoha EN7523 SoC system clocks"
+ depends on OF
+ depends on ARCH_AIROHA || ARM || COMPILE_TEST
+ default ARCH_AIROHA
+ help
+ This driver provides the fixed clocks and gates present on Airoha
+ ARM silicon.
+
config COMMON_CLK_FSL_FLEXSPI
tristate "Clock driver for FlexSPI on Layerscape SoCs"
depends on ARCH_LAYERSCAPE || COMPILE_TEST
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index e42312121e51..be11d88c1603 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
obj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
obj-$(CONFIG_ARCH_SPARX5) += clk-sparx5.o
+obj-$(CONFIG_COMMON_CLK_EN7523) += clk-en7523.o
obj-$(CONFIG_COMMON_CLK_FIXED_MMIO) += clk-fixed-mmio.o
obj-$(CONFIG_COMMON_CLK_FSL_FLEXSPI) += clk-fsl-flexspi.o
obj-$(CONFIG_COMMON_CLK_FSL_SAI) += clk-fsl-sai.o
diff --git a/drivers/clk/clk-en7523.c b/drivers/clk/clk-en7523.c
new file mode 100644
index 000000000000..f1774a5bf537
--- /dev/null
+++ b/drivers/clk/clk-en7523.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/regmap.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/en7523-clk.h>
+#include <linux/clk.h>
+
+#define REG_PCI_CONTROL 0x88
+#define REG_PCI_CONTROL_PERSTOUT BIT(29)
+#define REG_PCI_CONTROL_PERSTOUT1 BIT(26)
+#define REG_PCI_CONTROL_REFCLK_EN1 BIT(22)
+#define REG_GSW_CLK_DIV_SEL 0x1b4
+#define REG_EMI_CLK_DIV_SEL 0x1b8
+#define REG_BUS_CLK_DIV_SEL 0x1bc
+#define REG_SPI_CLK_DIV_SEL 0x1c4
+#define REG_SPI_CLK_FREQ_SEL 0x1c8
+#define REG_NPU_CLK_DIV_SEL 0x1fc
+#define REG_CRYPTO_CLKSRC 0x200
+#define REG_RESET_CONTROL 0x834
+#define REG_RESET_CONTROL_PCIEHB BIT(29)
+#define REG_RESET_CONTROL_PCIE1 BIT(27)
+#define REG_RESET_CONTROL_PCIE2 BIT(26)
+
+struct en_clk_desc {
+ int id;
+ const char *name;
+ u32 base_reg;
+ u32 base_bits;
+ u32 base_shift;
+ union {
+ const u32 *base_values;
+ u32 base_value;
+ };
+ int n_base_values;
+
+ u32 div_reg;
+ u32 div_bits;
+ u32 div_shift;
+ u32 div_val0;
+ u32 div_step;
+};
+
+struct en_clk_gate {
+ void __iomem *base;
+ struct clk_hw hw;
+};
+
+static const u32 gsw_base[] = { 400000000, 500000000 };
+static const u32 emi_base[] = { 333000000, 400000000 };
+static const u32 bus_base[] = { 500000000, 540000000 };
+static const u32 slic_base[] = { 100000000, 3125000 };
+static const u32 npu_base[] = { 333000000, 400000000, 500000000 };
+
+static const struct en_clk_desc en7523_base_clks[] = {
+ {
+ .id = EN7523_CLK_GSW,
+ .name = "gsw",
+
+ .base_reg = REG_GSW_CLK_DIV_SEL,
+ .base_bits = 1,
+ .base_shift = 8,
+ .base_values = gsw_base,
+ .n_base_values = ARRAY_SIZE(gsw_base),
+
+ .div_bits = 3,
+ .div_shift = 0,
+ .div_step = 1,
+ }, {
+ .id = EN7523_CLK_EMI,
+ .name = "emi",
+
+ .base_reg = REG_EMI_CLK_DIV_SEL,
+ .base_bits = 1,
+ .base_shift = 8,
+ .base_values = emi_base,
+ .n_base_values = ARRAY_SIZE(emi_base),
+
+ .div_bits = 3,
+ .div_shift = 0,
+ .div_step = 1,
+ }, {
+ .id = EN7523_CLK_BUS,
+ .name = "bus",
+
+ .base_reg = REG_BUS_CLK_DIV_SEL,
+ .base_bits = 1,
+ .base_shift = 8,
+ .base_values = bus_base,
+ .n_base_values = ARRAY_SIZE(bus_base),
+
+ .div_bits = 3,
+ .div_shift = 0,
+ .div_step = 1,
+ }, {
+ .id = EN7523_CLK_SLIC,
+ .name = "slic",
+
+ .base_reg = REG_SPI_CLK_FREQ_SEL,
+ .base_bits = 1,
+ .base_shift = 0,
+ .base_values = slic_base,
+ .n_base_values = ARRAY_SIZE(slic_base),
+
+ .div_reg = REG_SPI_CLK_DIV_SEL,
+ .div_bits = 5,
+ .div_shift = 24,
+ .div_val0 = 20,
+ .div_step = 2,
+ }, {
+ .id = EN7523_CLK_SPI,
+ .name = "spi",
+
+ .base_reg = REG_SPI_CLK_DIV_SEL,
+
+ .base_value = 400000000,
+
+ .div_bits = 5,
+ .div_shift = 8,
+ .div_val0 = 40,
+ .div_step = 2,
+ }, {
+ .id = EN7523_CLK_NPU,
+ .name = "npu",
+
+ .base_reg = REG_NPU_CLK_DIV_SEL,
+ .base_bits = 2,
+ .base_shift = 8,
+ .base_values = npu_base,
+ .n_base_values = ARRAY_SIZE(npu_base),
+
+ .div_bits = 3,
+ .div_shift = 0,
+ .div_step = 1,
+ }, {
+ .id = EN7523_CLK_CRYPTO,
+ .name = "crypto",
+
+ .base_reg = REG_CRYPTO_CLKSRC,
+ .base_bits = 1,
+ .base_shift = 8,
+ .base_values = emi_base,
+ .n_base_values = ARRAY_SIZE(emi_base),
+ }
+};
+
+static const struct of_device_id of_match_clk_en7523[] = {
+ { .compatible = "airoha,en7523-scu", },
+ { /* sentinel */ }
+};
+
+static u32 en7523_get_base_rate(void __iomem *base, int i)
+{
+ const struct en_clk_desc *desc = &en7523_base_clks[i];
+ u32 val;
+
+ if (!desc->base_bits)
+ return desc->base_value;
+
+ val = readl(base + desc->base_reg);
+ val >>= desc->base_shift;
+ val &= (1 << desc->base_bits) - 1;
+
+ if (val >= desc->n_base_values)
+ return 0;
+
+ return desc->base_values[val];
+}
+
+static u32 en7523_get_div(void __iomem *base, int i)
+{
+ const struct en_clk_desc *desc = &en7523_base_clks[i];
+ u32 reg, val;
+
+ if (!desc->div_bits)
+ return 1;
+
+ reg = desc->div_reg ? desc->div_reg : desc->base_reg;
+ val = readl(base + reg);
+ val >>= desc->div_shift;
+ val &= (1 << desc->div_bits) - 1;
+
+ if (!val && desc->div_val0)
+ return desc->div_val0;
+
+ return (val + 1) * desc->div_step;
+}
+
+static int en7523_pci_is_enabled(struct clk_hw *hw)
+{
+ struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+
+ return !!(readl(cg->base + REG_PCI_CONTROL) & REG_PCI_CONTROL_REFCLK_EN1);
+}
+
+static int en7523_pci_enable(struct clk_hw *hw)
+{
+ struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+ void *np_base = cg->base;
+ u32 val, mask;
+
+ /* Need to pull device low before reset */
+ val = readl(np_base + REG_PCI_CONTROL);
+ val &= ~(REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT);
+ writel(val, np_base + REG_PCI_CONTROL);
+ usleep_range(1000, 2000);
+
+ /* Enable PCIe port 1 */
+ val |= REG_PCI_CONTROL_REFCLK_EN1;
+ writel(val, np_base + REG_PCI_CONTROL);
+ usleep_range(1000, 2000);
+
+ /* Reset to default */
+ val = readl(np_base + REG_RESET_CONTROL);
+ mask = REG_RESET_CONTROL_PCIE1 | REG_RESET_CONTROL_PCIE2 |
+ REG_RESET_CONTROL_PCIEHB;
+ writel(val & ~mask, np_base + REG_RESET_CONTROL);
+ usleep_range(1000, 2000);
+ writel(val | mask, np_base + REG_RESET_CONTROL);
+ msleep(100);
+ writel(val & ~mask, np_base + REG_RESET_CONTROL);
+ usleep_range(5000, 10000);
+
+ /* Release device */
+ mask = REG_PCI_CONTROL_PERSTOUT1 | REG_PCI_CONTROL_PERSTOUT;
+ val = readl(np_base + REG_PCI_CONTROL);
+ writel(val & ~mask, np_base + REG_PCI_CONTROL);
+ usleep_range(1000, 2000);
+ writel(val | mask, np_base + REG_PCI_CONTROL);
+ msleep(250);
+
+ return 0;
+}
+
+static void en7523_pci_disable(struct clk_hw *hw)
+{
+ struct en_clk_gate *cg = container_of(hw, struct en_clk_gate, hw);
+ void *np_base = cg->base;
+ u32 val;
+
+ val = readl(np_base + REG_PCI_CONTROL);
+ val &= ~REG_PCI_CONTROL_REFCLK_EN1;
+ writel(val, np_base + REG_PCI_CONTROL);
+}
+
+static struct clk *en7523_register_pcie_clk(struct device *dev,
+ void __iomem *np_base)
+{
+ static const struct clk_ops pcie_gate_ops = {
+ .is_enabled = en7523_pci_is_enabled,
+ .enable = en7523_pci_enable,
+ .disable = en7523_pci_disable,
+ };
+ struct clk_init_data init = {
+ .name = "pcie",
+ .ops = &pcie_gate_ops,
+ };
+ struct en_clk_gate *cg;
+ struct clk *clk;
+
+ cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
+ if (!cg)
+ return NULL;
+
+ cg->base = np_base;
+ cg->hw.init = &init;
+ en7523_pci_disable(&cg->hw);
+
+ clk = clk_register(NULL, &cg->hw);
+ if (IS_ERR(clk))
+ clk = NULL;
+
+ return clk;
+}
+
+static void en7523_register_clocks(struct device *dev, struct clk_onecell_data *clk_data,
+ void __iomem *base, void __iomem *np_base)
+{
+ struct clk *clk;
+ u32 rate;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(en7523_base_clks); i++) {
+ const struct en_clk_desc *desc = &en7523_base_clks[i];
+
+ rate = en7523_get_base_rate(base, i);
+ rate /= en7523_get_div(base, i);
+
+ clk = clk_register_fixed_rate(NULL, desc->name, NULL, 0, rate);
+ if (IS_ERR(clk)) {
+ pr_err("Failed to register clk %s: %ld\n",
+ desc->name, PTR_ERR(clk));
+ continue;
+ }
+
+ clk_data->clks[desc->id] = clk;
+ }
+
+ clk = en7523_register_pcie_clk(dev, np_base);
+ clk_data->clks[EN7523_CLK_PCIE] = clk;
+
+ clk_data->clk_num = EN7523_NUM_CLOCKS;
+}
+
+static int en7523_clk_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct clk_onecell_data *clk_data;
+ void __iomem *base, *np_base;
+ int r;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ np_base = devm_platform_ioremap_resource(pdev, 1);
+ if (IS_ERR(base))
+ return PTR_ERR(np_base);
+
+ clk_data = devm_kzalloc(&pdev->dev, sizeof(*clk_data), GFP_KERNEL);
+ if (!clk_data)
+ return -ENOMEM;
+
+ clk_data->clks = devm_kcalloc(&pdev->dev, EN7523_NUM_CLOCKS,
+ sizeof(*clk_data->clks), GFP_KERNEL);
+ if (!clk_data->clks)
+ return -ENOMEM;
+
+ en7523_register_clocks(&pdev->dev, clk_data, base, np_base);
+
+ r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+ if (r)
+ dev_err(&pdev->dev,
+ "could not register clock provider: %s: %d\n",
+ pdev->name, r);
+
+ return r;
+}
+
+static struct platform_driver clk_en7523_drv = {
+ .probe = en7523_clk_probe,
+ .driver = {
+ .name = "clk-en7523",
+ .of_match_table = of_match_clk_en7523,
+ },
+};
+
+static int clk_en7523_init(void)
+{
+ return platform_driver_register(&clk_en7523_drv);
+}
+
+arch_initcall(clk_en7523_init);