Add Sunplus SoC PWM Driver
Signed-off-by: Hammer Hsieh <hammerh0314@xxxxxxxxx>
---
Changes in v2:
- Addressed all comments from Uwe Kleine-König.
- rebase kernel to 5.17 rc5
MAINTAINERS | 1 +
drivers/pwm/Kconfig | 11 +++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-sunplus.c | 229 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 242 insertions(+)
create mode 100644 drivers/pwm/pwm-sunplus.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 825b714..8710c8e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18535,6 +18535,7 @@ SUNPLUS PWM DRIVER
M: Hammer Hsieh <hammerh0314@xxxxxxxxx>
S: Maintained
F: Documentation/devicetree/bindings/pwm/pwm-sunplus.yaml
+F: drivers/pwm/pwm-sunplus.c
SUNPLUS RTC DRIVER
M: Vincent Shih <vincent.sunplus@xxxxxxxxx>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 21e3b05..54cfb50 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -572,6 +572,17 @@ config PWM_SUN4I
To compile this driver as a module, choose M here: the module
will be called pwm-sun4i.
+config PWM_SUNPLUS
+ tristate "Sunplus PWM support"
+ depends on ARCH_SUNPLUS || COMPILE_TEST
+ depends on HAS_IOMEM && OF
+ help
+ Generic PWM framework driver for the PWM controller on
+ Sunplus SoCs.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-sunplus.
+
config PWM_TEGRA
tristate "NVIDIA Tegra PWM support"
depends on ARCH_TEGRA || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 708840b..be58616 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PWM_STM32) += pwm-stm32.o
obj-$(CONFIG_PWM_STM32_LP) += pwm-stm32-lp.o
obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o
obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o
+obj-$(CONFIG_PWM_SUNPLUS) += pwm-sunplus.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o
obj-$(CONFIG_PWM_TIEHRPWM) += pwm-tiehrpwm.o
diff --git a/drivers/pwm/pwm-sunplus.c b/drivers/pwm/pwm-sunplus.c
new file mode 100644
index 0000000..170534f
--- /dev/null
+++ b/drivers/pwm/pwm-sunplus.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PWM device driver for SUNPLUS SoCs
+ *
+ * Limitations:
+ * - Only supports normal polarity.
+ *
+ * Author: Hammer Hsieh <hammerh0314@xxxxxxxxx>
+ */
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define PWM_SUP_CONTROL0 0x000
+#define PWM_SUP_CONTROL1 0x004
+#define PWM_SUP_FREQ_BASE 0x008
+#define PWM_SUP_DUTY_BASE 0x018
+#define PWM_SUP_FREQ(ch) (PWM_SUP_FREQ_BASE + 4 * (ch))
+#define PWM_SUP_DUTY(ch) (PWM_SUP_DUTY_BASE + 4 * (ch))
+#define PWM_SUP_FREQ_MAX GENMASK(15, 0)
+#define PWM_SUP_DUTY_MAX GENMASK(7, 0)
+
+#define PWM_SUP_NUM 4
+#define PWM_BYPASS_BIT_SHIFT 8
+#define PWM_DD_SEL_BIT_SHIFT 8
+#define PWM_SUP_FREQ_SCALER 256
+
+struct sunplus_pwm {
+ struct pwm_chip chip;
+ void __iomem *base;
+ struct clk *clk;
+ u32 approx_period[PWM_SUP_NUM];
+ u32 approx_duty_cycle[PWM_SUP_NUM];
+};
+
+static inline struct sunplus_pwm *to_sunplus_pwm(struct pwm_chip *chip)
+{
+ return container_of(chip, struct sunplus_pwm, chip);
+}
+
+static void sunplus_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct sunplus_pwm *priv = to_sunplus_pwm(chip);
+ u32 value;
+
+ /* disable pwm channel output */
+ value = readl(priv->base + PWM_SUP_CONTROL0);
+ value &= ~BIT(pwm->hwpwm);
+ writel(value, priv->base + PWM_SUP_CONTROL0);
+ /* disable pwm channel clk source */
+ value = readl(priv->base + PWM_SUP_CONTROL1);
+ value &= ~BIT(pwm->hwpwm);
+ writel(value, priv->base + PWM_SUP_CONTROL1);
+}
+
+static int sunplus_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct sunplus_pwm *priv = to_sunplus_pwm(chip);
+ u32 dd_freq, duty, value, value1;
+ u32 tmp, rate;
+ u64 max_period, period_ns, duty_ns, clk_rate;
+
+ if (state->polarity != pwm->state.polarity)
+ return -EINVAL;
+
+ if (!state->enabled) {
+ /* disable pwm channel output */
+ value = readl(priv->base + PWM_SUP_CONTROL0);
+ value &= ~BIT(pwm->hwpwm);
+ writel(value, priv->base + PWM_SUP_CONTROL0);
+ /* disable pwm channel clk source */
+ value = readl(priv->base + PWM_SUP_CONTROL1);
+ value &= ~BIT(pwm->hwpwm);
+ writel(value, priv->base + PWM_SUP_CONTROL1);
+ return 0;
+ }
+
+ clk_rate = clk_get_rate(priv->clk);
+ rate = (u32)clk_rate / 100000;
+ max_period = PWM_SUP_FREQ_MAX * (PWM_SUP_FREQ_SCALER * 10000 / rate);
+
+ if (state->period > max_period)
+ return -EINVAL;
+
+ period_ns = state->period;
+ duty_ns = state->duty_cycle;
+
+ priv->approx_period[pwm->hwpwm] = (u32)period_ns / 100;
+ priv->approx_duty_cycle[pwm->hwpwm] = (u32)duty_ns / 100;
+
+ /* cal pwm freq and check value under range */
+ dd_freq = rate * priv->approx_period[pwm->hwpwm] / (PWM_SUP_FREQ_SCALER * 100);
+
+ if (dd_freq == 0)
+ return -EINVAL;
+
+ if (dd_freq > PWM_SUP_FREQ_MAX)
+ dd_freq = PWM_SUP_FREQ_MAX;
+
+ writel(dd_freq, priv->base + PWM_SUP_FREQ(pwm->hwpwm));
+
+ /* cal and set pwm duty */
+ value = readl(priv->base + PWM_SUP_CONTROL0);
+ value |= BIT(pwm->hwpwm);
+ value1 = readl(priv->base + PWM_SUP_CONTROL1);
+ value1 |= BIT(pwm->hwpwm);
+ if (duty_ns == period_ns) {
+ value |= BIT(pwm->hwpwm + PWM_BYPASS_BIT_SHIFT);
+ duty = PWM_SUP_DUTY_MAX;
+ } else {
+ value &= ~BIT(pwm->hwpwm + PWM_BYPASS_BIT_SHIFT);
+ tmp = priv->approx_duty_cycle[pwm->hwpwm] * PWM_SUP_FREQ_SCALER;
+ tmp /= priv->approx_period[pwm->hwpwm];
+ duty = (u32)tmp;
+ duty |= (pwm->hwpwm << PWM_DD_SEL_BIT_SHIFT);
+ }
+ writel(duty, priv->base + PWM_SUP_DUTY(pwm->hwpwm));
+ writel(value1, priv->base + PWM_SUP_CONTROL1);
+ writel(value, priv->base + PWM_SUP_CONTROL0);
+
+ return 0;
+}
+
+static void sunplus_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct sunplus_pwm *priv = to_sunplus_pwm(chip);
+ u32 value, freq, duty, rate, freq_tmp, duty_tmp;
+ u64 tmp, clk_rate;
+
+ value = readl(priv->base + PWM_SUP_CONTROL0);
+
+ if (value & BIT(pwm->hwpwm)) {
+ clk_rate = clk_get_rate(priv->clk);
+ rate = (u32)clk_rate / 100000;
+ freq = readl(priv->base + PWM_SUP_FREQ(pwm->hwpwm));
+ duty = readl(priv->base + PWM_SUP_DUTY(pwm->hwpwm));
+ duty &= ~GENMASK(9, 8);
+
+ freq_tmp = rate * priv->approx_period[pwm->hwpwm] / (PWM_SUP_FREQ_SCALER * 100);
+ duty_tmp = priv->approx_duty_cycle[pwm->hwpwm] * PWM_SUP_FREQ_SCALER /
+ priv->approx_period[pwm->hwpwm];
+
+ if (freq == freq_tmp && duty == duty_tmp) {
+ state->period = priv->approx_period[pwm->hwpwm] * 100;
+ state->duty_cycle = priv->approx_duty_cycle[pwm->hwpwm] * 100;
+ } else {
+ tmp = (u64)freq * PWM_SUP_FREQ_SCALER * 10000;
+ state->period = div64_u64(tmp, rate);
+ tmp = (u64)freq * (u64)duty * 10000;
+ state->duty_cycle = div64_u64(tmp, rate);
+ }
+ state->enabled = true;
+ } else {
+ state->enabled = false;
+ }
+
+ state->polarity = PWM_POLARITY_NORMAL;
+}
+
+static const struct pwm_ops sunplus_pwm_ops = {
+ .free = sunplus_pwm_free,
+ .apply = sunplus_pwm_apply,
+ .get_state = sunplus_pwm_get_state,
+ .owner = THIS_MODULE,
+};
+
+static int sunplus_pwm_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sunplus_pwm *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk = devm_clk_get_optional(dev, NULL);
+ if (IS_ERR(priv->clk))
+ return dev_err_probe(dev, PTR_ERR(priv->clk),
+ "get pwm clock failed\n");
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev,
+ (void(*)(void *))clk_disable_unprepare,
+ priv->clk);
+ if (ret)
+ return ret;
+
+ priv->chip.dev = dev;
+ priv->chip.ops = &sunplus_pwm_ops;
+ priv->chip.npwm = PWM_SUP_NUM;
+
+ ret = devm_pwmchip_add(dev, &priv->chip);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Cannot register sunplus PWM\n");
+
+ return 0;
+}
+
+static const struct of_device_id sunplus_pwm_of_match[] = {
+ { .compatible = "sunplus,sp7021-pwm", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, sunplus_pwm_of_match);
+
+static struct platform_driver sunplus_pwm_driver = {
+ .probe = sunplus_pwm_probe,
+ .driver = {
+ .name = "sunplus-pwm",
+ .of_match_table = sunplus_pwm_of_match,
+ },
+};
+module_platform_driver(sunplus_pwm_driver);
+
+MODULE_DESCRIPTION("Sunplus SoC PWM Driver");
+MODULE_AUTHOR("Hammer Hsieh <hammerh0314@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.7.4
