+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2017 Sanechips Technology Co., Ltd.
- * Copyright 2017 Linaro Ltd.
- */
-
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/pwm.h>
-#include <linux/slab.h>
-
-#define ZX_PWM_MODE 0x0
-#define ZX_PWM_CLKDIV_SHIFT 2
-#define ZX_PWM_CLKDIV_MASK GENMASK(11, 2)
-#define ZX_PWM_CLKDIV(x) (((x) << ZX_PWM_CLKDIV_SHIFT) & \
- ZX_PWM_CLKDIV_MASK)
-#define ZX_PWM_POLAR BIT(1)
-#define ZX_PWM_EN BIT(0)
-#define ZX_PWM_PERIOD 0x4
-#define ZX_PWM_DUTY 0x8
-
-#define ZX_PWM_CLKDIV_MAX 1023
-#define ZX_PWM_PERIOD_MAX 65535
-
-struct zx_pwm_chip {
- struct pwm_chip chip;
- struct clk *pclk;
- struct clk *wclk;
- void __iomem *base;
-};
-
-static inline struct zx_pwm_chip *to_zx_pwm_chip(struct pwm_chip *chip)
-{
- return container_of(chip, struct zx_pwm_chip, chip);
-}
-
-static inline u32 zx_pwm_readl(struct zx_pwm_chip *zpc, unsigned int hwpwm,
- unsigned int offset)
-{
- return readl(zpc->base + (hwpwm + 1) * 0x10 + offset);
-}
-
-static inline void zx_pwm_writel(struct zx_pwm_chip *zpc, unsigned int hwpwm,
- unsigned int offset, u32 value)
-{
- writel(value, zpc->base + (hwpwm + 1) * 0x10 + offset);
-}
-
-static void zx_pwm_set_mask(struct zx_pwm_chip *zpc, unsigned int hwpwm,
- unsigned int offset, u32 mask, u32 value)
-{
- u32 data;
-
- data = zx_pwm_readl(zpc, hwpwm, offset);
- data &= ~mask;
- data |= value & mask;
- zx_pwm_writel(zpc, hwpwm, offset, data);
-}
-
-static void zx_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
- struct pwm_state *state)
-{
- struct zx_pwm_chip *zpc = to_zx_pwm_chip(chip);
- unsigned long rate;
- unsigned int div;
- u32 value;
- u64 tmp;
-
- value = zx_pwm_readl(zpc, pwm->hwpwm, ZX_PWM_MODE);
-
- if (value & ZX_PWM_POLAR)
- state->polarity = PWM_POLARITY_NORMAL;
- else
- state->polarity = PWM_POLARITY_INVERSED;
-
- if (value & ZX_PWM_EN)
- state->enabled = true;
- else
- state->enabled = false;
-
- div = (value & ZX_PWM_CLKDIV_MASK) >> ZX_PWM_CLKDIV_SHIFT;
- rate = clk_get_rate(zpc->wclk);
-
- tmp = zx_pwm_readl(zpc, pwm->hwpwm, ZX_PWM_PERIOD);
- tmp *= div * NSEC_PER_SEC;
- state->period = DIV_ROUND_CLOSEST_ULL(tmp, rate);
-
- tmp = zx_pwm_readl(zpc, pwm->hwpwm, ZX_PWM_DUTY);
- tmp *= div * NSEC_PER_SEC;
- state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, rate);
-}
-
-static int zx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- unsigned int duty_ns, unsigned int period_ns)
-{
- struct zx_pwm_chip *zpc = to_zx_pwm_chip(chip);
- unsigned int period_cycles, duty_cycles;
- unsigned long long c;
- unsigned int div = 1;
- unsigned long rate;
-
- /* Find out the best divider */
- rate = clk_get_rate(zpc->wclk);
-
- while (1) {
- c = rate / div;
- c = c * period_ns;
- do_div(c, NSEC_PER_SEC);
-
- if (c < ZX_PWM_PERIOD_MAX)
- break;
-
- div++;
-
- if (div > ZX_PWM_CLKDIV_MAX)
- return -ERANGE;
- }
-
- /* Calculate duty cycles */
- period_cycles = c;
- c *= duty_ns;
- do_div(c, period_ns);
- duty_cycles = c;
-
- /*
- * If the PWM is being enabled, we have to temporarily disable it
- * before configuring the registers.
- */
- if (pwm_is_enabled(pwm))
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE, ZX_PWM_EN, 0);
-
- /* Set up registers */
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE, ZX_PWM_CLKDIV_MASK,
- ZX_PWM_CLKDIV(div));
- zx_pwm_writel(zpc, pwm->hwpwm, ZX_PWM_PERIOD, period_cycles);
- zx_pwm_writel(zpc, pwm->hwpwm, ZX_PWM_DUTY, duty_cycles);
-
- /* Re-enable the PWM if needed */
- if (pwm_is_enabled(pwm))
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE,
- ZX_PWM_EN, ZX_PWM_EN);
-
- return 0;
-}
-
-static int zx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
- const struct pwm_state *state)
-{
- struct zx_pwm_chip *zpc = to_zx_pwm_chip(chip);
- struct pwm_state cstate;
- int ret;
-
- pwm_get_state(pwm, &cstate);
-
- if (state->polarity != cstate.polarity)
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE, ZX_PWM_POLAR,
- (state->polarity == PWM_POLARITY_INVERSED) ?
- 0 : ZX_PWM_POLAR);
-
- if (state->period != cstate.period ||
- state->duty_cycle != cstate.duty_cycle) {
- ret = zx_pwm_config(chip, pwm, state->duty_cycle,
- state->period);
- if (ret)
- return ret;
- }
-
- if (state->enabled != cstate.enabled) {
- if (state->enabled) {
- ret = clk_prepare_enable(zpc->wclk);
- if (ret)
- return ret;
-
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE,
- ZX_PWM_EN, ZX_PWM_EN);
- } else {
- zx_pwm_set_mask(zpc, pwm->hwpwm, ZX_PWM_MODE,
- ZX_PWM_EN, 0);
- clk_disable_unprepare(zpc->wclk);
- }
- }
-
- return 0;
-}
-
-static const struct pwm_ops zx_pwm_ops = {
- .apply = zx_pwm_apply,
- .get_state = zx_pwm_get_state,
- .owner = THIS_MODULE,
-};
-
-static int zx_pwm_probe(struct platform_device *pdev)
-{
- struct zx_pwm_chip *zpc;
- unsigned int i;
- int ret;
-
- zpc = devm_kzalloc(&pdev->dev, sizeof(*zpc), GFP_KERNEL);
- if (!zpc)
- return -ENOMEM;
-
- zpc->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(zpc->base))
- return PTR_ERR(zpc->base);
-
- zpc->pclk = devm_clk_get(&pdev->dev, "pclk");
- if (IS_ERR(zpc->pclk))
- return PTR_ERR(zpc->pclk);
-
- zpc->wclk = devm_clk_get(&pdev->dev, "wclk");
- if (IS_ERR(zpc->wclk))
- return PTR_ERR(zpc->wclk);
-
- ret = clk_prepare_enable(zpc->pclk);
- if (ret)
- return ret;
-
- zpc->chip.dev = &pdev->dev;
- zpc->chip.ops = &zx_pwm_ops;
- zpc->chip.base = -1;
- zpc->chip.npwm = 4;
- zpc->chip.of_xlate = of_pwm_xlate_with_flags;
- zpc->chip.of_pwm_n_cells = 3;
-
- /*
- * PWM devices may be enabled by firmware, and let's disable all of
- * them initially to save power.
- */
- for (i = 0; i < zpc->chip.npwm; i++)
- zx_pwm_set_mask(zpc, i, ZX_PWM_MODE, ZX_PWM_EN, 0);
-
- ret = pwmchip_add(&zpc->chip);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
- clk_disable_unprepare(zpc->pclk);
- return ret;
- }
-
- platform_set_drvdata(pdev, zpc);
-
- return 0;
-}
-
-static int zx_pwm_remove(struct platform_device *pdev)
-{
- struct zx_pwm_chip *zpc = platform_get_drvdata(pdev);
- int ret;
-
- ret = pwmchip_remove(&zpc->chip);
- clk_disable_unprepare(zpc->pclk);
-
- return ret;
-}
-
-static const struct of_device_id zx_pwm_dt_ids[] = {
- { .compatible = "zte,zx296718-pwm", },
- { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, zx_pwm_dt_ids);
-
-static struct platform_driver zx_pwm_driver = {
- .driver = {
- .name = "zx-pwm",
- .of_match_table = zx_pwm_dt_ids,
- },
- .probe = zx_pwm_probe,
- .remove = zx_pwm_remove,
-};
-module_platform_driver(zx_pwm_driver);
-
-MODULE_ALIAS("platform:zx-pwm");
-MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
-MODULE_DESCRIPTION("ZTE ZX PWM Driver");
-MODULE_LICENSE("GPL v2");
projects / mirror_ubuntu-jammy-kernel.git / commitdiff