--- /dev/null
+/*
+ * PWM driver for Rockchip SoCs
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ * Copyright (C) 2014 ROCKCHIP, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/time.h>
+
+#define PWM_CTRL_TIMER_EN (1 << 0)
+#define PWM_CTRL_OUTPUT_EN (1 << 3)
+
+#define PWM_ENABLE (1 << 0)
+#define PWM_CONTINUOUS (1 << 1)
+#define PWM_DUTY_POSITIVE (1 << 3)
+#define PWM_DUTY_NEGATIVE (0 << 3)
+#define PWM_INACTIVE_NEGATIVE (0 << 4)
+#define PWM_INACTIVE_POSITIVE (1 << 4)
+#define PWM_OUTPUT_LEFT (0 << 5)
+#define PWM_LP_DISABLE (0 << 8)
+
+struct rockchip_pwm_chip {
+ struct pwm_chip chip;
+ struct clk *clk;
+ const struct rockchip_pwm_data *data;
+ void __iomem *base;
+};
+
+struct rockchip_pwm_regs {
+ unsigned long duty;
+ unsigned long period;
+ unsigned long cntr;
+ unsigned long ctrl;
+};
+
+struct rockchip_pwm_data {
+ struct rockchip_pwm_regs regs;
+ unsigned int prescaler;
+ const struct pwm_ops *ops;
+
+ void (*set_enable)(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable);
+};
+
+static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
+{
+ return container_of(c, struct rockchip_pwm_chip, chip);
+}
+
+static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
+ u32 val;
+
+ val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+ if (enable)
+ val |= enable_conf;
+ else
+ val &= ~enable_conf;
+
+ writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
+static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip,
+ struct pwm_device *pwm, bool enable)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+ PWM_CONTINUOUS;
+ u32 val;
+
+ if (pwm->polarity == PWM_POLARITY_INVERSED)
+ enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
+ else
+ enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
+
+ val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+ if (enable)
+ val |= enable_conf;
+ else
+ val &= ~enable_conf;
+
+ writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
+static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ unsigned long period, duty;
+ u64 clk_rate, div;
+ int ret;
+
+ clk_rate = clk_get_rate(pc->clk);
+
+ /*
+ * Since period and duty cycle registers have a width of 32
+ * bits, every possible input period can be obtained using the
+ * default prescaler value for all practical clock rate values.
+ */
+ div = clk_rate * period_ns;
+ do_div(div, pc->data->prescaler * NSEC_PER_SEC);
+ period = div;
+
+ div = clk_rate * duty_ns;
+ do_div(div, pc->data->prescaler * NSEC_PER_SEC);
+ duty = div;
+
+ ret = clk_enable(pc->clk);
+ if (ret)
+ return ret;
+
+ writel(period, pc->base + pc->data->regs.period);
+ writel(duty, pc->base + pc->data->regs.duty);
+ writel(0, pc->base + pc->data->regs.cntr);
+
+ clk_disable(pc->clk);
+
+ return 0;
+}
+
+static int rockchip_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ /*
+ * No action needed here because pwm->polarity will be set by the core
+ * and the core will only change polarity when the PWM is not enabled.
+ * We'll handle things in set_enable().
+ */
+
+ return 0;
+}
+
+static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+ int ret;
+
+ ret = clk_enable(pc->clk);
+ if (ret)
+ return ret;
+
+ pc->data->set_enable(chip, pwm, true);
+
+ return 0;
+}
+
+static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+
+ pc->data->set_enable(chip, pwm, false);
+
+ clk_disable(pc->clk);
+}
+
+static const struct pwm_ops rockchip_pwm_ops_v1 = {
+ .config = rockchip_pwm_config,
+ .enable = rockchip_pwm_enable,
+ .disable = rockchip_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static const struct pwm_ops rockchip_pwm_ops_v2 = {
+ .config = rockchip_pwm_config,
+ .set_polarity = rockchip_pwm_set_polarity,
+ .enable = rockchip_pwm_enable,
+ .disable = rockchip_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static const struct rockchip_pwm_data pwm_data_v1 = {
+ .regs = {
+ .duty = 0x04,
+ .period = 0x08,
+ .cntr = 0x00,
+ .ctrl = 0x0c,
+ },
+ .prescaler = 2,
+ .ops = &rockchip_pwm_ops_v1,
+ .set_enable = rockchip_pwm_set_enable_v1,
+};
+
+static const struct rockchip_pwm_data pwm_data_v2 = {
+ .regs = {
+ .duty = 0x08,
+ .period = 0x04,
+ .cntr = 0x00,
+ .ctrl = 0x0c,
+ },
+ .prescaler = 1,
+ .ops = &rockchip_pwm_ops_v2,
+ .set_enable = rockchip_pwm_set_enable_v2,
+};
+
+static const struct rockchip_pwm_data pwm_data_vop = {
+ .regs = {
+ .duty = 0x08,
+ .period = 0x04,
+ .cntr = 0x0c,
+ .ctrl = 0x00,
+ },
+ .prescaler = 1,
+ .ops = &rockchip_pwm_ops_v2,
+ .set_enable = rockchip_pwm_set_enable_v2,
+};
+
+static const struct of_device_id rockchip_pwm_dt_ids[] = {
+ { .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
+ { .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
+ { .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
+
+static int rockchip_pwm_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *id;
+ struct rockchip_pwm_chip *pc;
+ struct resource *r;
+ int ret;
+
+ id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
+ if (!id)
+ return -EINVAL;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pc->base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(pc->base))
+ return PTR_ERR(pc->base);
+
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk))
+ return PTR_ERR(pc->clk);
+
+ ret = clk_prepare(pc->clk);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, pc);
+
+ pc->data = id->data;
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = pc->data->ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = 1;
+
+ if (pc->data->ops->set_polarity) {
+ pc->chip.of_xlate = of_pwm_xlate_with_flags;
+ pc->chip.of_pwm_n_cells = 3;
+ }
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ clk_unprepare(pc->clk);
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ }
+
+ return ret;
+}
+
+static int rockchip_pwm_remove(struct platform_device *pdev)
+{
+ struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
+
+ clk_unprepare(pc->clk);
+
+ return pwmchip_remove(&pc->chip);
+}
+
+static struct platform_driver rockchip_pwm_driver = {
+ .driver = {
+ .name = "rockchip-pwm",
+ .of_match_table = rockchip_pwm_dt_ids,
+ },
+ .probe = rockchip_pwm_probe,
+ .remove = rockchip_pwm_remove,
+};
+module_platform_driver(rockchip_pwm_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Rockchip SoC PWM driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff