From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Chenjieqin Date: Fri, 8 Jan 2021 03:56:54 +0800 Subject: pwm: sifive-ptc: Add SiFive PWM PTC driver yiming.li: clear CNTR of PWM after setting period & duty_cycle Emil: cleanups, clock, reset and div_u64 Signed-off-by: Emil Renner Berthing --- drivers/pwm/Kconfig | 11 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-sifive-ptc.c | 260 ++++++++++ 3 files changed, 272 insertions(+) diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 60d13a949bc5..89cd8a6406e3 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -504,6 +504,17 @@ config PWM_SIFIVE To compile this driver as a module, choose M here: the module will be called pwm-sifive. +config PWM_SIFIVE_PTC + tristate "SiFive PWM PTC support" + depends on SOC_SIFIVE || SOC_STARFIVE || COMPILE_TEST + depends on OF + depends on COMMON_CLK + help + Generic PWM framework driver for SiFive SoCs. + + To compile this driver as a module, choose M here: the module + will be called pwm-sifive-ptc. + config PWM_SL28CPLD tristate "Kontron sl28cpld PWM support" depends on MFD_SL28CPLD || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 7bf1a29f02b8..fbaa279cf540 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o +obj-$(CONFIG_PWM_SIFIVE_PTC) += pwm-sifive-ptc.o obj-$(CONFIG_PWM_SL28CPLD) += pwm-sl28cpld.o obj-$(CONFIG_PWM_SPEAR) += pwm-spear.o obj-$(CONFIG_PWM_SPRD) += pwm-sprd.o diff --git a/drivers/pwm/pwm-sifive-ptc.c b/drivers/pwm/pwm-sifive-ptc.c new file mode 100644 index 000000000000..cc68d136b82c --- /dev/null +++ b/drivers/pwm/pwm-sifive-ptc.c @@ -0,0 +1,260 @@ +/* + * Copyright (C) 2018 SiFive, 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 +#include +#include +#include +#include +#include +#include + +#include + +/* max channel of pwm */ +#define MAX_PWM 8 + +/* 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_1 1000000000U + +/* 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) + +/* pwm ptc device */ +struct sifive_pwm_ptc_device { + struct pwm_chip chip; + struct clk *clk; + void __iomem *regs; +}; + +static inline struct sifive_pwm_ptc_device *chip_to_sifive_ptc(struct pwm_chip *c) +{ + return container_of(c, struct sifive_pwm_ptc_device, chip); +} + +static int sifive_pwm_ptc_get_state(struct pwm_chip *chip, struct pwm_device *dev, + struct pwm_state *state) +{ + struct sifive_pwm_ptc_device *pwm = chip_to_sifive_ptc(chip); + u32 data_lrc; + u32 data_hrc; + u32 pwm_clk_ns = 0; + + /* get lrc and hrc data from registe */ + data_lrc = ioread32(REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm)); + data_hrc = ioread32(REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm)); + + /* how many ns does apb clock elapse */ + pwm_clk_ns = NS_1 / clk_get_rate(pwm->clk); + + /* pwm period(ns) */ + state->period = data_lrc * pwm_clk_ns; + + /* duty cycle(ns) means high level eclapse ns if it is normal polarity */ + state->duty_cycle = data_hrc * pwm_clk_ns; + + /* polarity, we don't use it now because it is not in dts */ + state->polarity = PWM_POLARITY_NORMAL; + + /* enabled or not */ + state->enabled = 1; + + dev_dbg(pwm->chip.dev, "%s: no:%d\n", __func__, dev->hwpwm); + dev_dbg(pwm->chip.dev, "data_hrc:0x%x 0x%x\n", data_hrc, data_lrc); + dev_dbg(pwm->chip.dev, "period:%llu\n", state->period); + dev_dbg(pwm->chip.dev, "duty_cycle:%llu\n", state->duty_cycle); + dev_dbg(pwm->chip.dev, "polarity:%d\n", state->polarity); + dev_dbg(pwm->chip.dev, "enabled:%d\n", state->enabled); + + return 0; +} + +static int sifive_pwm_ptc_apply(struct pwm_chip *chip, struct pwm_device *dev, + const struct pwm_state *state) +{ + struct sifive_pwm_ptc_device *pwm = chip_to_sifive_ptc(chip); + void __iomem *reg_addr; + u32 pwm_clk_ns = 0; + u32 data_hrc = 0; + u32 data_lrc = 0; + u32 period_data = 0; + u32 duty_data = 0; + + dev_dbg(pwm->chip.dev, "%s: no:%d\n", __func__, dev->hwpwm); + dev_dbg(pwm->chip.dev, "period:%llu\n", state->period); + dev_dbg(pwm->chip.dev, "duty_cycle:%llu\n", state->duty_cycle); + dev_dbg(pwm->chip.dev, "polarity:%d\n", state->polarity); + dev_dbg(pwm->chip.dev, "enabled:%d\n", state->enabled); + + /* duty_cycle should be less or equal than period */ + if (state->duty_cycle > state->period) + return -EINVAL; + + /* calculate pwm real period (ns) */ + pwm_clk_ns = NS_1 / clk_get_rate(pwm->clk); + + dev_dbg(pwm->chip.dev, "pwm_clk_ns:%u\n", pwm_clk_ns); + + /* calculate period count */ + period_data = div_u64(state->period, pwm_clk_ns); + + if (!state->enabled) + /* if disabled, just set duty_data to 0, which means low level always */ + duty_data = 0; + else + /* calculate duty count */ + duty_data = div_u64(state->duty_cycle, pwm_clk_ns); + + dev_dbg(pwm->chip.dev, "period_data:%u, duty_data:%u\n", + period_data, duty_data); + + if (state->polarity == PWM_POLARITY_NORMAL) + /* calculate data_hrc */ + data_hrc = period_data - duty_data; + else + /* calculate data_hrc */ + data_hrc = duty_data; + + data_lrc = period_data; + + /* set hrc */ + reg_addr = REG_PTC_RPTC_HRC(pwm->regs, dev->hwpwm); + dev_dbg(pwm->chip.dev, "%s: reg_addr:%p, data:%u\n", + __func__, reg_addr, data_hrc); + + iowrite32(data_hrc, reg_addr); + + dev_dbg(pwm->chip.dev, "%s: hrc ok\n", __func__); + + /* set lrc */ + reg_addr = REG_PTC_RPTC_LRC(pwm->regs, dev->hwpwm); + dev_dbg(pwm->chip.dev, "%s: reg_addr:%p, data:%u\n", + __func__, reg_addr, data_lrc); + + iowrite32(data_lrc, reg_addr); + dev_dbg(pwm->chip.dev, "%s: lrc ok\n", __func__); + + /* Clear REG_RPTC_CNTR after setting period & duty_cycle */ + reg_addr = REG_PTC_RPTC_CNTR(pwm->regs, dev->hwpwm); + iowrite32(0, reg_addr); + return 0; +} + +static const struct pwm_ops sifive_pwm_ptc_ops = { + .get_state = sifive_pwm_ptc_get_state, + .apply = sifive_pwm_ptc_apply, + .owner = THIS_MODULE, +}; + +static void sifive_pwm_ptc_disable_action(void *data) +{ + clk_disable_unprepare(data); +} + +static int sifive_pwm_ptc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *node = pdev->dev.of_node; + struct sifive_pwm_ptc_device *pwm; + struct pwm_chip *chip; + struct reset_control *rst; + int ret; + + pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + platform_set_drvdata(pdev, pwm); + + chip = &pwm->chip; + chip->dev = dev; + chip->ops = &sifive_pwm_ptc_ops; + + /* how many parameters can be transferred to ptc, need to fix */ + chip->of_pwm_n_cells = 3; + chip->base = -1; + + /* get pwm channels count, max value is 8 */ + ret = of_property_read_u32(node, "starfive,npwm", &chip->npwm); + if (ret < 0 || chip->npwm > MAX_PWM) + chip->npwm = MAX_PWM; + + dev_dbg(dev, "%s: npwm:0x%x\n", __func__, chip->npwm); + + /* get IO base address */ + 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 controller clock\n"); + + ret = clk_prepare_enable(pwm->clk); + if (ret) + return dev_err_probe(dev, ret, "Unable to enable clock\n"); + + ret = devm_add_action_or_reset(dev, sifive_pwm_ptc_disable_action, pwm->clk); + if (ret) + return ret; + + rst = devm_reset_control_get_exclusive(dev, NULL); + if (IS_ERR(rst)) + return dev_err_probe(dev, PTR_ERR(rst), "Unable to get reset\n"); + + ret = reset_control_deassert(rst); + if (ret) + return dev_err_probe(dev, ret, "Unable to deassert reset\n"); + + /* + * after pwmchip_add it will show up as /sys/class/pwm/pwmchip0, + * 0 is chip->base, pwm0 can be seen after running echo 0 > export + */ + ret = devm_pwmchip_add(dev, chip); + if (ret) + return dev_err_probe(dev, ret, "cannot register PTC: %d\n", ret); + + dev_dbg(dev, "SiFive PWM PTC chip registered %d PWMs\n", chip->npwm); + return 0; +} + +static const struct of_device_id sifive_pwm_ptc_of_match[] = { + { .compatible = "starfive,pwm0" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sifive_pwm_ptc_of_match); + +static struct platform_driver sifive_pwm_ptc_driver = { + .probe = sifive_pwm_ptc_probe, + .driver = { + .name = "pwm-sifive-ptc", + .of_match_table = sifive_pwm_ptc_of_match, + }, +}; +module_platform_driver(sifive_pwm_ptc_driver); + +MODULE_DESCRIPTION("SiFive PWM PTC driver"); +MODULE_LICENSE("GPL v2"); -- Armbian