[PATCH v5 2/2] pwm: sophgo: add pwm support for Sophgo CV1800 SoC
Jingbao Qiu
qiujingbao.dlmu at gmail.com
Thu Mar 14 03:01:31 PDT 2024
Implement the PWM driver for CV1800.
Signed-off-by: Jingbao Qiu <qiujingbao.dlmu at gmail.com>
---
drivers/pwm/Kconfig | 10 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-cv1800.c | 315 +++++++++++++++++++++++++++++++++++++++
3 files changed, 326 insertions(+)
create mode 100644 drivers/pwm/pwm-cv1800.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 4b956d661755..455f07af94f7 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -186,6 +186,16 @@ config PWM_CROS_EC
PWM driver for exposing a PWM attached to the ChromeOS Embedded
Controller.
+config PWM_CV1800
+ tristate "Sophgo CV1800 PWM driver"
+ depends on ARCH_SOPHGO || COMPILE_TEST
+ help
+ Generic PWM framework driver for the Sophgo CV1800 series
+ SoCs.
+
+ To compile this driver as a module, build the dependecies
+ as modules, this will be called pwm-cv1800.
+
config PWM_DWC_CORE
tristate
depends on HAS_IOMEM
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c5ec9e168ee7..6c3c4a07a316 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CLK) += pwm-clk.o
obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o
obj-$(CONFIG_PWM_CRC) += pwm-crc.o
obj-$(CONFIG_PWM_CROS_EC) += pwm-cros-ec.o
+obj-$(CONFIG_PWM_CV1800) += pwm-cv1800.o
obj-$(CONFIG_PWM_DWC_CORE) += pwm-dwc-core.o
obj-$(CONFIG_PWM_DWC) += pwm-dwc.o
obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
diff --git a/drivers/pwm/pwm-cv1800.c b/drivers/pwm/pwm-cv1800.c
new file mode 100644
index 000000000000..8eca07c60942
--- /dev/null
+++ b/drivers/pwm/pwm-cv1800.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Sophgo CV1800 PWM driver
+ * Author: Jingbao Qiu <qiujingbao.dlmu at gmail.com>
+ *
+ * Limitations:
+ * - It output low when PWM channel disabled.
+ * - This pwm device supports dynamic loading of PWM parameters. When PWMSTART
+ * is written from 0 to 1, the register value (HLPERIODn, PERIODn) will be
+ * temporarily stored inside the PWM. If you want to dynamically change the
+ * waveform during PWM output, after writing the new value to HLPERIODn and
+ * PERIODn, write 1 and then 0 to PWMUPDATE[n] to make the new value effective.
+ * - Supports up to Rate/2 output, and the lowest is about Rate/(2^30-1).
+ * - By setting HLPERIODn to 0, can produce 100% duty cycle.
+ * - This hardware could support inverted polarity. By default, the value of the
+ * POLARITY register is 0x0. This means that HLPERIOD represents the number
+ * of low level beats.
+ * - This hardware supports input mode and output mode, implemented through the
+ * Output-Enable/OE register. However, this driver has not yet implemented
+ * capture callback.
+ */
+
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+#define PWM_CV1800_HLPERIOD_BASE 0x00
+#define PWM_CV1800_PERIOD_BASE 0x04
+#define PWM_CV1800_POLARITY 0x40
+#define PWM_CV1800_START 0x44
+#define PWM_CV1800_DONE 0x48
+#define PWM_CV1800_UPDATE 0x4c
+#define PWM_CV1800_OE 0xd0
+
+#define PWM_CV1800_HLPERIOD(n) (PWM_CV1800_HLPERIOD_BASE + ((n) * 0x08))
+#define PWM_CV1800_PERIOD(n) (PWM_CV1800_PERIOD_BASE + ((n) * 0x08))
+
+#define PWM_CV1800_UPDATE_MASK(n) (BIT(0) << (n))
+#define PWM_CV1800_OE_MASK(n) (BIT(0) << (n))
+#define PWM_CV1800_START_MASK(n) (BIT(0) << (n))
+#define PWM_CV1800_POLARITY_MASK(n) (BIT(0) << (n))
+
+#define PWM_CV1800_MAXPERIOD 0x3fffffff
+#define PWM_CV1800_MINPERIOD 2
+#define PWM_CV1800_CHANNELS 4
+#define PWM_CV1800_PERIOD_RESET BIT(1)
+#define PWM_CV1800_HLPERIOD_RESET BIT(0)
+#define PWM_CV1800_REG_DISABLE 0x00U
+#define PWM_CV1800_REG_ENABLE(n) (BIT(0) << (n))
+
+struct cv1800_pwm {
+ struct regmap *map;
+ struct clk *clk;
+ unsigned long clk_rate;
+};
+
+static inline struct cv1800_pwm *to_cv1800_pwm_dev(struct pwm_chip *chip)
+{
+ return pwmchip_get_drvdata(chip);
+}
+
+static const struct regmap_config cv1800_pwm_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static int cv1800_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
+ bool enable)
+{
+ struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+ u32 pwm_enable;
+
+ regmap_read(priv->map, PWM_CV1800_START, &pwm_enable);
+ pwm_enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
+
+ /*
+ * If the parameters are changed during runtime, Register needs
+ * to be updated to take effect.
+ */
+ if (pwm_enable && enable) {
+ regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
+ PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
+ PWM_CV1800_REG_ENABLE(pwm->hwpwm));
+ regmap_update_bits(priv->map, PWM_CV1800_UPDATE,
+ PWM_CV1800_UPDATE_MASK(pwm->hwpwm),
+ PWM_CV1800_REG_DISABLE);
+ } else if (!pwm_enable && enable) {
+ regmap_update_bits(priv->map, PWM_CV1800_START,
+ PWM_CV1800_START_MASK(pwm->hwpwm),
+ PWM_CV1800_REG_ENABLE(pwm->hwpwm));
+ } else if (pwm_enable && !enable) {
+ regmap_update_bits(priv->map, PWM_CV1800_START,
+ PWM_CV1800_START_MASK(pwm->hwpwm),
+ PWM_CV1800_REG_DISABLE);
+ }
+
+ return 0;
+}
+
+static void cv1800_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+ u32 config_polarity = 0;
+
+ if (pwm->state.enabled)
+ cv1800_pwm_enable(chip, pwm, !pwm->state.enabled);
+
+ if (polarity == PWM_POLARITY_INVERSED)
+ config_polarity = PWM_CV1800_POLARITY_MASK(pwm->hwpwm);
+
+ regmap_update_bits(priv->map, PWM_CV1800_POLARITY,
+ PWM_CV1800_POLARITY_MASK(pwm->hwpwm),
+ config_polarity);
+}
+
+/**
+ * cv1800_pwm_set_oe() - check and config nth channal output-enable/OE mode
+ * @chip: PWM chip
+ * @pwm: PWM device
+ * @mode: The nth bit of the mode represents the output-enable/OE mode
+ * of the nth channal. 1 represents output mode, 0 represents
+ * input mode.
+ */
+static void cv1800_pwm_set_oe(struct pwm_chip *chip, struct pwm_device *pwm,
+ u32 mode)
+{
+ struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+ u32 state;
+
+ regmap_read(priv->map, PWM_CV1800_OE, &state);
+ state &= PWM_CV1800_OE_MASK(pwm->hwpwm);
+
+ if (state == mode)
+ return;
+
+ /* disenable pwm output before changing output mode */
+ cv1800_pwm_enable(chip, pwm, false);
+
+ regmap_update_bits(priv->map, PWM_CV1800_OE,
+ PWM_CV1800_OE_MASK(pwm->hwpwm), mode);
+}
+
+static int cv1800_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+ u32 period_val, hlperiod_val;
+ u64 ticks;
+
+ cv1800_pwm_set_oe(chip, pwm, PWM_CV1800_OE_MASK(pwm->hwpwm));
+
+ if (state->polarity != pwm->state.polarity)
+ cv1800_pwm_set_polarity(chip, pwm, state->polarity);
+
+ /*
+ * This hardware use PERIOD and HLPERIOD registers to represent PWM waves.
+ *
+ * The meaning of PERIOD is how many clock cycles (from the clock source)
+ * are used to represent PWM waves.
+ * PERIOD = rate(MHz) / target(MHz)
+ * PERIOD = period(ns) * rate(Hz) / NSEC_PER_SEC
+ */
+ ticks = mul_u64_u64_div_u64(state->period, priv->clk_rate,
+ NSEC_PER_SEC);
+ if (ticks < PWM_CV1800_MINPERIOD)
+ return -EINVAL;
+
+ if (ticks > PWM_CV1800_MAXPERIOD)
+ ticks = PWM_CV1800_MAXPERIOD;
+ period_val = (u32)ticks;
+
+ /*
+ * After mapping, hlperiod represents the same polarity as duty.
+ * HLPERIOD = rate(MHz) / duty(MHz)
+ * HLPERIOD = duty(ns) * rate(Hz) / NSEC_PER_SEC
+ */
+ ticks = mul_u64_u64_div_u64(state->duty_cycle, priv->clk_rate,
+ NSEC_PER_SEC);
+ if (ticks > period_val)
+ ticks = period_val;
+ hlperiod_val = (u32)ticks;
+
+ regmap_write(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), period_val);
+ regmap_write(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), hlperiod_val);
+
+ cv1800_pwm_enable(chip, pwm, state->enabled);
+
+ return 0;
+}
+
+static int cv1800_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct cv1800_pwm *priv = to_cv1800_pwm_dev(chip);
+ u32 period_val, hlperiod_val;
+ u64 period_ns = 0, duty_ns = 0;
+ u32 enable = 0, polarity = 0;
+
+ regmap_read(priv->map, PWM_CV1800_PERIOD(pwm->hwpwm), &period_val);
+ regmap_read(priv->map, PWM_CV1800_HLPERIOD(pwm->hwpwm), &hlperiod_val);
+
+ if (period_val != PWM_CV1800_PERIOD_RESET ||
+ hlperiod_val != PWM_CV1800_HLPERIOD_RESET) {
+ period_ns = DIV_ROUND_UP_ULL(period_val * NSEC_PER_SEC,
+ priv->clk_rate);
+ duty_ns = DIV_ROUND_UP_ULL(hlperiod_val * NSEC_PER_SEC,
+ priv->clk_rate);
+
+ regmap_read(priv->map, PWM_CV1800_START, &enable);
+ enable &= PWM_CV1800_START_MASK(pwm->hwpwm);
+
+ regmap_read(priv->map, PWM_CV1800_POLARITY, &polarity);
+ polarity &= PWM_CV1800_POLARITY_MASK(pwm->hwpwm);
+ }
+
+ state->period = period_ns;
+ state->duty_cycle = duty_ns;
+ state->enabled = enable;
+
+ /*
+ * To ensure that duty and hlperiod represent the same polarity
+ * the following mapping needs to be completed.
+ *
+ * |----------|------------|------------|-----------|
+ * | Linux | register | duty | register |
+ * | polarity | polarity | | hlperiod |
+ * |----------|------------|------------|-----------|
+ * | 1 | 0 | low level | low level |
+ * |----------|------------|------------|-----------|
+ * | 0 | 1 | high level | high level|
+ * |----------|------------|------------|-----------|
+ */
+ state->polarity = polarity ? PWM_POLARITY_NORMAL :
+ PWM_POLARITY_INVERSED;
+
+ return 0;
+}
+
+static const struct pwm_ops cv1800_pwm_ops = {
+ .apply = cv1800_pwm_apply,
+ .get_state = cv1800_pwm_get_state,
+};
+
+static int cv1800_pwm_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct cv1800_pwm *priv;
+ struct pwm_chip *chip;
+ void __iomem *base;
+ int ret;
+
+ chip = devm_pwmchip_alloc(dev, PWM_CV1800_CHANNELS, sizeof(*priv));
+ if (!chip)
+ return PTR_ERR(chip);
+ priv = to_cv1800_pwm_dev(chip);
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ priv->map = devm_regmap_init_mmio(&pdev->dev, base,
+ &cv1800_pwm_regmap_config);
+ if (IS_ERR(priv->map))
+ return PTR_ERR(priv->map);
+
+ priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
+ "clk not found\n");
+
+ ret = devm_clk_rate_exclusive_get(dev, priv->clk);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "failed to get exclusive rate\n");
+
+ priv->clk_rate = clk_get_rate(priv->clk);
+ if (!priv->clk_rate)
+ return dev_err_probe(&pdev->dev, -EINVAL,
+ "Invalid clock rate: %lu\n",
+ priv->clk_rate);
+
+ chip->ops = &cv1800_pwm_ops;
+
+ ret = devm_pwmchip_add(dev, chip);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+
+ return 0;
+}
+
+static const struct of_device_id cv1800_pwm_dt_ids[] = {
+ { .compatible = "sophgo,cv1800-pwm" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, cv1800_pwm_dt_ids);
+
+static struct platform_driver cv1800_pwm_driver = {
+ .probe = cv1800_pwm_probe,
+ .driver = {
+ .name = "cv1800-pwm",
+ .of_match_table = cv1800_pwm_dt_ids,
+ },
+};
+module_platform_driver(cv1800_pwm_driver);
+
+MODULE_AUTHOR("Jingbao Qiu");
+MODULE_DESCRIPTION("Sophgo cv1800 PWM Driver");
+MODULE_LICENSE("GPL");
--
2.25.1
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