--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PWM driver for the StarFive JH7110 SoC
+ *
+ * Copyright (C) 2018 StarFive Technology Co., Ltd.
+ */
+
+#include <dt-bindings/pwm/pwm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/io.h>
+
+/* how many parameters can be transferred to ptc */
+#define OF_PWM_N_CELLS 3
+
+/* PTC Register offsets */
+#define REG_RPTC_CNTR 0x0
+#define REG_RPTC_HRC 0x4
+#define REG_RPTC_LRC 0x8
+#define REG_RPTC_CTRL 0xC
+
+/* Bit for PWM clock */
+#define BIT_PWM_CLOCK_EN 31
+
+/* Bit for clock gen soft reset */
+#define BIT_CLK_GEN_SOFT_RESET 13
+
+#define NS_PER_SECOND 1000000000
+
+/*
+ * Access PTC register (cntr hrc lrc and ctrl),
+ * need to replace PWM_BASE_ADDR
+ */
+#define REG_PTC_BASE_ADDR_SUB(base, N) \
+((base) + (((N) > 3) ? (((N) % 4) * 0x10 + (1 << 15)) : ((N) * 0x10)))
+#define REG_PTC_RPTC_CNTR(base, N) (REG_PTC_BASE_ADDR_SUB(base, N))
+#define REG_PTC_RPTC_HRC(base, N) (REG_PTC_BASE_ADDR_SUB(base, N) + 0x4)
+#define REG_PTC_RPTC_LRC(base, N) (REG_PTC_BASE_ADDR_SUB(base, N) + 0x8)
+#define REG_PTC_RPTC_CTRL(base, N) (REG_PTC_BASE_ADDR_SUB(base, N) + 0xC)
+
+/* PTC_RPTC_CTRL */
+#define PTC_EN BIT(0)
+#define PTC_ECLK BIT(1)
+#define PTC_NEC BIT(2)
+#define PTC_OE BIT(3)
+#define PTC_SIGNLE BIT(4)
+#define PTC_INTE BIT(5)
+#define PTC_INT BIT(6)
+#define PTC_CNTRRST BIT(7)
+#define PTC_CAPTE BIT(8)
+
+struct starfive_pwm_ptc_device {
+ struct pwm_chip chip;
+ struct clk *clk;
+ struct reset_control *rst;
+ void __iomem *regs;
+ int irq;
+ unsigned int approx_freq;/*pwm apb clock frequency*/
+};
+
+static inline
+struct starfive_pwm_ptc_device *chip_to_starfive_ptc(struct pwm_chip *c)
+{
+ return container_of(c, struct starfive_pwm_ptc_device, chip);
+}
+
+static int starfive_pwm_ptc_get_state(struct pwm_chip *chip,
+ struct pwm_device *dev,
+ struct pwm_state *state)
+{
+ struct starfive_pwm_ptc_device *pwm = chip_to_starfive_ptc(chip);
+ u32 data_lrc, data_hrc;
+ u32 pwm_clk_ns = 0;
+
+ data_lrc = ioread32(REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm));
+ data_hrc = ioread32(REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm));
+
+ pwm_clk_ns = NS_PER_SECOND / pwm->approx_freq;
+
+ state->period = data_lrc * pwm_clk_ns;
+ state->duty_cycle = data_hrc * pwm_clk_ns;
+ state->polarity = PWM_POLARITY_NORMAL;
+ state->enabled = 1;
+
+ return 0;
+}
+
+static int starfive_pwm_ptc_apply(struct pwm_chip *chip,
+ struct pwm_device *dev,
+ struct pwm_state *state)
+{
+ struct starfive_pwm_ptc_device *pwm = chip_to_starfive_ptc(chip);
+ u32 data_hrc = 0;
+ u32 data_lrc = 0;
+ u32 period_data = 0;
+ u32 duty_data = 0;
+ s64 multi = pwm->approx_freq;
+ s64 div = NS_PER_SECOND;
+ void __iomem *reg_addr;
+
+ if (state->duty_cycle > state->period)
+ state->duty_cycle = state->period;
+
+ while (multi % 10 == 0 && div % 10 == 0 && multi > 0 && div > 0) {
+ multi /= 10;
+ div /= 10;
+ }
+
+ period_data = (u32)(state->period * multi / div);
+ if (abs(period_data * div / multi - state->period)
+ > abs((period_data + 1) * div / multi - state->period) ||
+ (state->period > 0 && period_data == 0))
+ period_data += 1;
+
+ if (state->enabled) {
+ duty_data = (u32)(state->duty_cycle * multi / div);
+ if (abs(duty_data * div / multi - state->duty_cycle)
+ > abs((duty_data + 1) * div / multi - state->duty_cycle) ||
+ (state->duty_cycle > 0 && duty_data == 0))
+ duty_data += 1;
+ } else {
+ duty_data = 0;
+ }
+
+ if (state->polarity == PWM_POLARITY_NORMAL)
+ data_hrc = period_data - duty_data;
+ else
+ data_hrc = duty_data;
+
+ data_lrc = period_data;
+
+ reg_addr = REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm);
+ iowrite32(data_hrc, reg_addr);
+
+ reg_addr = REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm);
+ iowrite32(data_lrc, reg_addr);
+
+ reg_addr = REG_PTC_RPTC_CNTR(pwm->regs, dev->hwpwm);
+ iowrite32(0, reg_addr);
+
+ reg_addr = REG_PTC_RPTC_CTRL(pwm->regs, dev->hwpwm);
+ iowrite32(PTC_EN | PTC_OE, reg_addr);
+
+ return 0;
+}
+
+static const struct pwm_ops starfive_pwm_ptc_ops = {
+ .get_state = starfive_pwm_ptc_get_state,
+ .apply = (void *)starfive_pwm_ptc_apply,
+ .owner = THIS_MODULE,
+};
+
+static int starfive_pwm_ptc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct starfive_pwm_ptc_device *pwm;
+ struct pwm_chip *chip;
+ int ret;
+
+ pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL);
+ if (!pwm)
+ return -ENOMEM;
+
+ chip = &pwm->chip;
+ chip->dev = dev;
+ chip->ops = &starfive_pwm_ptc_ops;
+ chip->npwm = 8;
+
+ chip->of_pwm_n_cells = OF_PWM_N_CELLS;
+ chip->base = -1;
+
+ pwm->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pwm->regs))
+ return dev_err_probe(dev, PTR_ERR(pwm->regs),
+ "Unable to map IO resources\n");
+
+ pwm->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(pwm->clk))
+ return dev_err_probe(dev, PTR_ERR(pwm->clk),
+ "Unable to get pwm clock\n");
+
+ pwm->rst = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(pwm->rst))
+ return dev_err_probe(dev, PTR_ERR(pwm->rst),
+ "Unable to get pwm reset\n");
+
+ ret = clk_prepare_enable(pwm->clk);
+ if (ret) {
+ dev_err(dev,
+ "Failed to enable pwm clock, %d\n", ret);
+ return ret;
+ }
+
+ reset_control_deassert(pwm->rst);
+
+ pwm->approx_freq = (unsigned int)clk_get_rate(pwm->clk);
+ if (!pwm->approx_freq)
+ dev_err(dev, "get pwm apb clock rate failed.\n");
+
+ ret = devm_pwmchip_add(dev, chip);
+ if (ret < 0) {
+ dev_err(dev, "cannot register PTC: %d\n", ret);
+ clk_disable_unprepare(pwm->clk);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, pwm);
+
+ return 0;
+}
+
+static int starfive_pwm_ptc_remove(struct platform_device *dev)
+{
+ struct starfive_pwm_ptc_device *pwm = platform_get_drvdata(dev);
+ struct pwm_chip *chip = &pwm->chip;
+
+ pwmchip_remove(chip);
+
+ return 0;
+}
+
+static const struct of_device_id starfive_pwm_ptc_of_match[] = {
+ { .compatible = "starfive,jh7110-pwm" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, starfive_pwm_ptc_of_match);
+
+static struct platform_driver starfive_pwm_ptc_driver = {
+ .probe = starfive_pwm_ptc_probe,
+ .remove = starfive_pwm_ptc_remove,
+ .driver = {
+ .name = "pwm-starfive-ptc",
+ .of_match_table = starfive_pwm_ptc_of_match,
+ },
+};
+module_platform_driver(starfive_pwm_ptc_driver);
+
+MODULE_AUTHOR("Jenny Zhang <jenny.zhang@starfivetech.com>");
+MODULE_AUTHOR("Hal Feng <hal.feng@starfivetech.com>");
+MODULE_DESCRIPTION("StarFive PWM PTC driver");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff