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msm8916-openwrt/target/linux/bcm27xx/patches-6.6/950-0538-pwm-Add-support-for-RP1-PWM.patch
Álvaro Fernández Rojas 8c405cdccc bcm27xx: add 6.6 kernel patches 
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.34..rpi-6.1.y

Some patches needed rebasing and, as usual, the applied and reverted, wireless
drivers, Github workflows, READMEs and defconfigs patches were removed.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-06-18 18:52:49 +02:00

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From 15d1815d753583c53d0d19e57123657d0a7a6706 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Tue, 14 Feb 2023 14:03:54 +0000
Subject: [PATCH 0538/1085] pwm: Add support for RP1 PWM
Add a driver for the RP1 PWM block.
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
.../devicetree/bindings/pwm/pwm-rp1.yaml | 38 ++++
drivers/pwm/Kconfig | 9 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-rp1.c | 203 ++++++++++++++++++
4 files changed, 251 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-rp1.yaml
create mode 100644 drivers/pwm/pwm-rp1.c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-rp1.yaml
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-rp1.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi RP1 PWM controller
+
+maintainers:
+ - Naushir Patuck <naush@raspberrypi.com>
+
+properties:
+ compatible:
+ enum:
+ - raspberrypi,rp1-pwm
+
+ reg:
+ maxItems: 1
+
+ "#pwm-cells":
+ const: 3
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - "#pwm-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ pwm0: pwm@98000 {
+ compatible = "raspberrypi,rp1-pwm";
+ reg = <0x0 0x98000 0x0 0x100>;
+ clocks = <&rp1_sys>;
+ #pwm-cells = <3>;
+ };
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -473,6 +473,15 @@ config PWM_RASPBERRYPI_POE
Enable Raspberry Pi firmware controller PWM bus used to control the
official RPI PoE hat
+config PWM_RP1
+ tristate "RP1 PWM support"
+ depends on ARCH_BCM2835 || COMPILE_TEST
+ help
+ PWM framework driver for Raspberry Pi RP1 controller
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-rp1.
+
config PWM_RCAR
tristate "Renesas R-Car PWM support"
depends on ARCH_RENESAS || COMPILE_TEST
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-om
obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o
obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_RASPBERRYPI_POE) += pwm-raspberrypi-poe.o
+obj-$(CONFIG_PWM_RP1) += pwm-rp1.o
obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o
obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o
obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o
--- /dev/null
+++ b/drivers/pwm/pwm-rp1.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * pwm-rp1.c
+ *
+ * Raspberry Pi RP1 PWM.
+ *
+ * Copyright © 2023 Raspberry Pi Ltd.
+ *
+ * Author: Naushir Patuck (naush@raspberrypi.com)
+ *
+ * Based on the pwm-bcm2835 driver by:
+ * Bart Tanghe <bart.tanghe@thomasmore.be>
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define PWM_GLOBAL_CTRL 0x000
+#define PWM_CHANNEL_CTRL(x) (0x014 + ((x) * 16))
+#define PWM_RANGE(x) (0x018 + ((x) * 16))
+#define PWM_DUTY(x) (0x020 + ((x) * 16))
+
+/* 8:FIFO_POP_MASK + 0:Trailing edge M/S modulation */
+#define PWM_CHANNEL_DEFAULT (BIT(8) + BIT(0))
+#define PWM_CHANNEL_ENABLE(x) BIT(x)
+#define PWM_POLARITY BIT(3)
+#define SET_UPDATE BIT(31)
+#define PWM_MODE_MASK GENMASK(1, 0)
+
+struct rp1_pwm {
+ struct pwm_chip chip;
+ struct device *dev;
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static inline struct rp1_pwm *to_rp1_pwm(struct pwm_chip *chip)
+{
+ return container_of(chip, struct rp1_pwm, chip);
+}
+
+static void rp1_pwm_apply_config(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct rp1_pwm *pc = to_rp1_pwm(chip);
+ u32 value;
+
+ value = readl(pc->base + PWM_GLOBAL_CTRL);
+ value |= SET_UPDATE;
+ writel(value, pc->base + PWM_GLOBAL_CTRL);
+}
+
+static int rp1_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct rp1_pwm *pc = to_rp1_pwm(chip);
+
+ writel(PWM_CHANNEL_DEFAULT, pc->base + PWM_CHANNEL_CTRL(pwm->hwpwm));
+ return 0;
+}
+
+static void rp1_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct rp1_pwm *pc = to_rp1_pwm(chip);
+ u32 value;
+
+ value = readl(pc->base + PWM_CHANNEL_CTRL(pwm->hwpwm));
+ value &= ~PWM_MODE_MASK;
+ writel(value, pc->base + PWM_CHANNEL_CTRL(pwm->hwpwm));
+ rp1_pwm_apply_config(chip, pwm);
+}
+
+static int rp1_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct rp1_pwm *pc = to_rp1_pwm(chip);
+ unsigned long clk_rate = clk_get_rate(pc->clk);
+ unsigned long clk_period;
+ u32 value;
+
+ if (!clk_rate) {
+ dev_err(pc->dev, "failed to get clock rate\n");
+ return -EINVAL;
+ }
+
+ /* set period */
+ clk_period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, clk_rate);
+
+ writel(DIV_ROUND_CLOSEST(state->duty_cycle, clk_period),
+ pc->base + PWM_DUTY(pwm->hwpwm));
+
+ /* set duty cycle */
+ writel(DIV_ROUND_CLOSEST(state->period, clk_period),
+ pc->base + PWM_RANGE(pwm->hwpwm));
+
+ /* set polarity */
+ value = readl(pc->base + PWM_CHANNEL_CTRL(pwm->hwpwm));
+ if (state->polarity == PWM_POLARITY_NORMAL)
+ value &= ~PWM_POLARITY;
+ else
+ value |= PWM_POLARITY;
+ writel(value, pc->base + PWM_CHANNEL_CTRL(pwm->hwpwm));
+
+ /* enable/disable */
+ value = readl(pc->base + PWM_GLOBAL_CTRL);
+ if (state->enabled)
+ value |= PWM_CHANNEL_ENABLE(pwm->hwpwm);
+ else
+ value &= ~PWM_CHANNEL_ENABLE(pwm->hwpwm);
+ writel(value, pc->base + PWM_GLOBAL_CTRL);
+
+ rp1_pwm_apply_config(chip, pwm);
+
+ return 0;
+}
+
+static const struct pwm_ops rp1_pwm_ops = {
+ .request = rp1_pwm_request,
+ .free = rp1_pwm_free,
+ .apply = rp1_pwm_apply,
+ .owner = THIS_MODULE,
+};
+
+static int rp1_pwm_probe(struct platform_device *pdev)
+{
+ struct rp1_pwm *pc;
+ struct resource *res;
+ int ret;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ pc->dev = &pdev->dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pc->base))
+ return PTR_ERR(pc->base);
+
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+ "clock not found\n");
+
+ ret = clk_prepare_enable(pc->clk);
+ if (ret)
+ return ret;
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &rp1_pwm_ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = 4;
+ pc->chip.of_xlate = of_pwm_xlate_with_flags;
+ pc->chip.of_pwm_n_cells = 3;
+
+ platform_set_drvdata(pdev, pc);
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0)
+ goto add_fail;
+
+ return 0;
+
+add_fail:
+ clk_disable_unprepare(pc->clk);
+ return ret;
+}
+
+static int rp1_pwm_remove(struct platform_device *pdev)
+{
+ struct rp1_pwm *pc = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(pc->clk);
+
+ pwmchip_remove(&pc->chip);
+
+ return 0;
+}
+
+static const struct of_device_id rp1_pwm_of_match[] = {
+ { .compatible = "raspberrypi,rp1-pwm" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rp1_pwm_of_match);
+
+static struct platform_driver rp1_pwm_driver = {
+ .driver = {
+ .name = "rpi-pwm",
+ .of_match_table = rp1_pwm_of_match,
+ },
+ .probe = rp1_pwm_probe,
+ .remove = rp1_pwm_remove,
+};
+module_platform_driver(rp1_pwm_driver);
+
+MODULE_AUTHOR("Naushir Patuck <naush@raspberrypi.com");
+MODULE_DESCRIPTION("RP1 PWM driver");
+MODULE_LICENSE("GPL");
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