| Message ID | 20221123061635.32025-5-billy_tsai@aspeedtech.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Support pwm/tach driver for aspeed ast26xx | expand |
On Wed, Nov 23, 2022 at 02:16:34PM +0800, Billy Tsai wrote: > Add the support of PWM controller which can be found at aspeed ast2600 > soc. The pwm supoorts up to 16 channels and it's part function of > multi-function device "pwm-tach controller". > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com> > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > Reported-by: kernel test robot <lkp@intel.com> Why do you add Reported-by from kernel test robot? I guess the bot reported issues on previous version of this patch series, then you fix them, right?
> From: Billy Tsai <billy_tsai@aspeedtech.com> > Sent: Wednesday, November 23, 2022 2:17 PM > To: jdelvare@suse.com; linux@roeck-us.net; robh+dt@kernel.org; > krzysztof.kozlowski+dt@linaro.org; joel@jms.id.au; andrew@aj.id.au; > lee@kernel.org; thierry.reding@gmail.com; u.kleine-koenig@pengutronix.de; > corbet@lwn.net; p.zabel@pengutronix.de; billy_tsai@aspeedtech.com; > linux-hwmon@vger.kernel.org; devicetree@vger.kernel.org; > linux-arm-kernel@lists.infradead.org; linux-aspeed@lists.ozlabs.org; > linux-kernel@vger.kernel.org; linux-pwm@vger.kernel.org; > linux-doc@vger.kernel.org > Cc: kernel test robot <lkp@intel.com> > Subject: [v4 4/5] pwm: Add Aspeed ast2600 PWM support > > Add the support of PWM controller which can be found at aspeed ast2600 soc. > The pwm supoorts up to 16 channels and it's part function of multi-function > device "pwm-tach controller". > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com> > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > Reported-by: kernel test robot <lkp@intel.com> > --- > drivers/pwm/Kconfig | 10 + > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-aspeed-ast2600.c | 318 > +++++++++++++++++++++++++++++++ > 3 files changed, 329 insertions(+) > create mode 100644 drivers/pwm/pwm-aspeed-ast2600.c > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index > 60d13a949bc5..54915185d918 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -51,6 +51,16 @@ config PWM_AB8500 > To compile this driver as a module, choose M here: the module > will be called pwm-ab8500. > > +config PWM_ASPEED_AST2600 > + tristate "Aspeed ast2600 PWM support" > + depends on ARCH_ASPEED || COMPILE_TEST > + depends on HAVE_CLK && HAS_IOMEM > + help > + This driver provides support for Aspeed ast2600 PWM controllers. > + > + To compile this driver as a module, choose M here: the module > + will be called pwm-aspeed-ast2600. > + > config PWM_ATMEL > tristate "Atmel PWM support" > depends on ARCH_AT91 || COMPILE_TEST > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index > 7bf1a29f02b8..5169c34056e6 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -2,6 +2,7 @@ > obj-$(CONFIG_PWM) += core.o > obj-$(CONFIG_PWM_SYSFS) += sysfs.o > obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o > +obj-$(CONFIG_PWM_ASPEED_AST2600) += pwm-aspeed-ast2600.o > obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o > obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o > obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o > diff --git a/drivers/pwm/pwm-aspeed-ast2600.c > b/drivers/pwm/pwm-aspeed-ast2600.c > new file mode 100644 > index 000000000000..2c22aff18624 > --- /dev/null > +++ b/drivers/pwm/pwm-aspeed-ast2600.c > @@ -0,0 +1,318 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) 2021 Aspeed Technology Inc. > + * > + * PWM controller driver for Aspeed ast2600 SoCs. > + * This drivers doesn't support earlier version of the IP. > + * > + * The hardware operates in time quantities of length > + * Q := (DIV_L + 1) << DIV_H / input-clk > + * The length of a PWM period is (DUTY_CYCLE_PERIOD + 1) * Q. > + * The maximal value for DUTY_CYCLE_PERIOD is used here to provide > + * a fine grained selection for the duty cycle. > + * > + * This driver uses DUTY_CYCLE_RISING_POINT = 0, so from the start of a > + * period the output is active until DUTY_CYCLE_FALLING_POINT * Q. Note > + * that if DUTY_CYCLE_RISING_POINT = DUTY_CYCLE_FALLING_POINT the > +output is > + * always active. > + * > + * Register usage: > + * PIN_ENABLE: When it is unset the pwm controller will emit inactive level to > the external. > + * Use to determine whether the PWM channel is enabled or disabled > + * CLK_ENABLE: When it is unset the pwm controller will assert the duty > +counter reset and > + * emit inactive level to the PIN_ENABLE mux after that the driver can > +still change the pwm period > + * and duty and the value will apply when CLK_ENABLE be set again. > + * Use to determine whether duty_cycle bigger than 0. > + * PWM_ASPEED_CTRL_INVERSE: When it is toggled the output value will > inverse immediately. > + * > +PWM_ASPEED_DUTY_CYCLE_FALLING_POINT/PWM_ASPEED_DUTY_CYCLE_R > ISING_POINT: > +When these two > + * values are equal it means the duty cycle = 100%. > + * > + * The glitch may generate at: > + * - Enabled changing when the duty_cycle bigger than 0% and less than > 100%. > + * - Polarity changing when the duty_cycle bigger than 0% and less than > 100%. > + * > + * Limitations: > + * - When changing both duty cycle and period, we cannot prevent in > + * software that the output might produce a period with mixed > + * settings. > + * - Disabling the PWM doesn't complete the current period. > + * > + * Improvements: > + * - When only changing one of duty cycle or period, our pwm controller will > not > + * generate the glitch, the configure will change at next cycle of pwm. > + * This improvement can disable/enable through > PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/errno.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/math64.h> > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/of_platform.h> > +#include <linux/platform_device.h> > +#include <linux/pwm.h> > +#include <linux/regmap.h> > +#include <linux/reset.h> > +#include <linux/sysfs.h> > + > +/* The channel number of Aspeed pwm controller */ > +#define PWM_ASPEED_NR_PWMS 16 > +/* PWM Control Register */ > +#define PWM_ASPEED_CTRL(ch) ((ch) * 0x10 + 0x00) > +#define PWM_ASPEED_CTRL_LOAD_SEL_RISING_AS_WDT BIT(19) > +#define PWM_ASPEED_CTRL_DUTY_LOAD_AS_WDT_ENABLE BIT(18) > +#define PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE BIT(17) > +#define PWM_ASPEED_CTRL_CLK_ENABLE BIT(16) > +#define PWM_ASPEED_CTRL_LEVEL_OUTPUT BIT(15) > +#define PWM_ASPEED_CTRL_INVERSE BIT(14) > +#define PWM_ASPEED_CTRL_OPEN_DRAIN_ENABLE BIT(13) > +#define PWM_ASPEED_CTRL_PIN_ENABLE BIT(12) > +#define PWM_ASPEED_CTRL_CLK_DIV_H GENMASK(11, 8) > +#define PWM_ASPEED_CTRL_CLK_DIV_L GENMASK(7, 0) > + > +/* PWM Duty Cycle Register */ > +#define PWM_ASPEED_DUTY_CYCLE(ch) ((ch) * 0x10 + 0x04) > +#define PWM_ASPEED_DUTY_CYCLE_PERIOD GENMASK(31, 24) > +#define PWM_ASPEED_DUTY_CYCLE_POINT_AS_WDT GENMASK(23, 16) > +#define PWM_ASPEED_DUTY_CYCLE_FALLING_POINT GENMASK(15, 8) > +#define PWM_ASPEED_DUTY_CYCLE_RISING_POINT GENMASK(7, 0) > + > +/* PWM fixed value */ > +#define PWM_ASPEED_FIXED_PERIOD > FIELD_MAX(PWM_ASPEED_DUTY_CYCLE_PERIOD) > + > +struct aspeed_pwm_data { > + struct pwm_chip chip; > + struct clk *clk; > + struct regmap *regmap; > + struct reset_control *reset; > +}; > + > +static inline struct aspeed_pwm_data * > +aspeed_pwm_chip_to_data(struct pwm_chip *chip) { > + return container_of(chip, struct aspeed_pwm_data, chip); } > + > +static void aspeed_pwm_get_state(struct pwm_chip *chip, struct void should be change to int > pwm_device *pwm, > + struct pwm_state *state) > +{ > + struct device *dev = chip->dev; > + struct aspeed_pwm_data *priv = aspeed_pwm_chip_to_data(chip); > + u32 hwpwm = pwm->hwpwm; > + bool polarity, pin_en, clk_en; > + u32 duty_pt, val; > + unsigned long rate; > + u64 div_h, div_l, duty_cycle_period, dividend; > + > + regmap_read(priv->regmap, PWM_ASPEED_CTRL(hwpwm), &val); > + polarity = FIELD_GET(PWM_ASPEED_CTRL_INVERSE, val); > + pin_en = FIELD_GET(PWM_ASPEED_CTRL_PIN_ENABLE, val); > + clk_en = FIELD_GET(PWM_ASPEED_CTRL_CLK_ENABLE, val); > + div_h = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_H, val); > + div_l = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_L, val); > + regmap_read(priv->regmap, PWM_ASPEED_DUTY_CYCLE(hwpwm), &val); > + duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val); > + duty_cycle_period = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_PERIOD, > val); > + > + rate = clk_get_rate(priv->clk); > + > + /* > + * This multiplication doesn't overflow, the upper bound is > + * 1000000000 * 256 * 256 << 15 = 0x1dcd650000000000 > + */ > + dividend = (u64)NSEC_PER_SEC * (div_l + 1) * (duty_cycle_period + 1) > + << div_h; > + state->period = DIV_ROUND_UP_ULL(dividend, rate); > + > + if (clk_en && duty_pt) { > + dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt > + << div_h; > + state->duty_cycle = DIV_ROUND_UP_ULL(dividend, rate); > + } else { > + state->duty_cycle = clk_en ? state->period : 0; > + } > + state->polarity = polarity ? PWM_POLARITY_INVERSED : > PWM_POLARITY_NORMAL; > + state->enabled = pin_en; > + dev_dbg(dev, "get period: %lldns, duty_cycle: %lldns", state->period, > + state->duty_cycle); Add return 0 here. > +} > + > +static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device > *pwm, > + const struct pwm_state *state) > +{ > + struct device *dev = chip->dev; > + struct aspeed_pwm_data *priv = aspeed_pwm_chip_to_data(chip); > + u32 hwpwm = pwm->hwpwm, duty_pt; > + unsigned long rate; > + u64 div_h, div_l, divisor, expect_period; > + bool clk_en; > + > + rate = clk_get_rate(priv->clk); > + expect_period = min(div64_u64(ULLONG_MAX, (u64)rate), > state->period); > + dev_dbg(dev, "expect period: %lldns, duty_cycle: %lldns", expect_period, > + state->duty_cycle); > + /* > + * Pick the smallest value for div_h so that div_l can be the biggest > + * which results in a finer resolution near the target period value. > + */ > + divisor = (u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1) * > + (FIELD_MAX(PWM_ASPEED_CTRL_CLK_DIV_L) + 1); > + div_h = order_base_2(DIV64_U64_ROUND_UP(rate * expect_period, > divisor)); > + if (div_h > 0xf) > + div_h = 0xf; > + > + divisor = ((u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1)) << > div_h; > + div_l = div64_u64(rate * expect_period, divisor); > + > + if (div_l == 0) > + return -ERANGE; > + > + div_l -= 1; > + > + if (div_l > 255) > + div_l = 255; > + > + dev_dbg(dev, "clk source: %ld div_h %lld, div_l : %lld\n", rate, div_h, > + div_l); > + /* duty_pt = duty_cycle * (PERIOD + 1) / period */ > + duty_pt = div64_u64(state->duty_cycle * rate, > + (u64)NSEC_PER_SEC * (div_l + 1) << div_h); > + dev_dbg(dev, "duty_cycle = %lld, duty_pt = %d\n", state->duty_cycle, > + duty_pt); > + > + /* > + * Fixed DUTY_CYCLE_PERIOD to its max value to get a > + * fine-grained resolution for duty_cycle at the expense of a > + * coarser period resolution. > + */ > + regmap_update_bits(priv->regmap, > PWM_ASPEED_DUTY_CYCLE(hwpwm), > + PWM_ASPEED_DUTY_CYCLE_PERIOD, > + FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_PERIOD, > + PWM_ASPEED_FIXED_PERIOD)); > + if (duty_pt == 0) { > + /* emit inactive level and assert the duty counter reset */ > + clk_en = 0; > + } else { > + clk_en = 1; > + if (duty_pt >= (PWM_ASPEED_FIXED_PERIOD + 1)) > + duty_pt = 0; > + regmap_update_bits(priv->regmap, > PWM_ASPEED_DUTY_CYCLE(hwpwm), > + PWM_ASPEED_DUTY_CYCLE_RISING_POINT | > + PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, > + > FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt)); > + } > + > + regmap_update_bits(priv->regmap, PWM_ASPEED_CTRL(hwpwm), > + PWM_ASPEED_CTRL_CLK_DIV_H | > PWM_ASPEED_CTRL_CLK_DIV_L | > + PWM_ASPEED_CTRL_PIN_ENABLE | > PWM_ASPEED_CTRL_CLK_ENABLE | > + PWM_ASPEED_CTRL_INVERSE, > + FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_H, div_h) | > + FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_L, div_l) | > + FIELD_PREP(PWM_ASPEED_CTRL_PIN_ENABLE, > state->enabled) | > + FIELD_PREP(PWM_ASPEED_CTRL_CLK_ENABLE, clk_en) > | > + FIELD_PREP(PWM_ASPEED_CTRL_INVERSE, > state->polarity)); > + return 0; > +} > + > +static const struct pwm_ops aspeed_pwm_ops = { > + .apply = aspeed_pwm_apply, > + .get_state = aspeed_pwm_get_state, We got compile error because the get_state is int but return type of aspeed_pwm_get_state is void. We found that the get_state had been change from void to int. Refer to linux/include/linux/pwm.h https://github.com/torvalds/linux/commit/6c452cff79f8bf1c0146fda598d32061cfd25443 Therefore, we think the return type of aspeed_pwm_get_state should be change to int. Could you help to revise this patch? > + .owner = THIS_MODULE, > +}; > + > +static void aspeed_pwm_reset_assert(void *data) { > + struct reset_control *rst = data; > + > + reset_control_assert(rst); > +} > + > +static void aspeed_pwm_chip_remove(void *data) { > + struct pwm_chip *chip = data; > + > + pwmchip_remove(chip); > +} > + > +static int aspeed_pwm_probe(struct platform_device *pdev) { > + struct device *dev = &pdev->dev; > + int ret; > + struct aspeed_pwm_data *priv; > + struct device_node *np; > + struct platform_device *parent_dev; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + np = pdev->dev.parent->of_node; > + if (!of_device_is_compatible(np, "aspeed,ast2600-pwm-tach")) > + return dev_err_probe(dev, -ENODEV, > + "Unsupported pwm device binding\n"); > + > + priv->regmap = syscon_node_to_regmap(np); > + if (IS_ERR(priv->regmap)) > + return dev_err_probe(dev, PTR_ERR(priv->regmap), > + "Couldn't get regmap\n"); > + > + parent_dev = of_find_device_by_node(np); > + priv->clk = devm_clk_get_enabled(&parent_dev->dev, NULL); > + if (IS_ERR(priv->clk)) > + return dev_err_probe(dev, PTR_ERR(priv->clk), > + "Couldn't get clock\n"); > + > + priv->reset = devm_reset_control_get_shared(&parent_dev->dev, NULL); > + if (IS_ERR(priv->reset)) > + return dev_err_probe(dev, PTR_ERR(priv->reset), > + "Couldn't get reset control\n"); > + > + ret = reset_control_deassert(priv->reset); > + if (ret) > + return dev_err_probe(dev, ret, > + "Couldn't deassert reset control\n"); > + > + ret = devm_add_action_or_reset(dev, aspeed_pwm_reset_assert, > + priv->reset); > + if (ret) > + return ret; > + > + priv->chip.dev = dev; > + priv->chip.ops = &aspeed_pwm_ops; > + priv->chip.npwm = PWM_ASPEED_NR_PWMS; > + > + ret = pwmchip_add(&priv->chip); > + if (ret < 0) > + return dev_err_probe(dev, ret, "Failed to add PWM chip\n"); > + ret = devm_add_action_or_reset(dev, aspeed_pwm_chip_remove, > + &priv->chip); > + if (ret) > + return ret; > + return 0; > +} > + > +static const struct of_device_id of_pwm_match_table[] = { > + { > + .compatible = "aspeed,ast2600-pwm", > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, of_pwm_match_table); > + > +static struct platform_driver aspeed_pwm_driver = { > + .probe = aspeed_pwm_probe, > + .driver = { > + .name = "aspeed-pwm", > + .of_match_table = of_pwm_match_table, > + }, > +}; > + > +module_platform_driver(aspeed_pwm_driver); > + > +MODULE_AUTHOR("Billy Tsai <billy_tsai@aspeedtech.com>"); > +MODULE_DESCRIPTION("Aspeed ast2600 PWM device driver"); > +MODULE_LICENSE("GPL"); > -- > 2.25.1
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 60d13a949bc5..54915185d918 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -51,6 +51,16 @@ config PWM_AB8500 To compile this driver as a module, choose M here: the module will be called pwm-ab8500. +config PWM_ASPEED_AST2600 + tristate "Aspeed ast2600 PWM support" + depends on ARCH_ASPEED || COMPILE_TEST + depends on HAVE_CLK && HAS_IOMEM + help + This driver provides support for Aspeed ast2600 PWM controllers. + + To compile this driver as a module, choose M here: the module + will be called pwm-aspeed-ast2600. + config PWM_ATMEL tristate "Atmel PWM support" depends on ARCH_AT91 || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 7bf1a29f02b8..5169c34056e6 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_SYSFS) += sysfs.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o +obj-$(CONFIG_PWM_ASPEED_AST2600) += pwm-aspeed-ast2600.o obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o diff --git a/drivers/pwm/pwm-aspeed-ast2600.c b/drivers/pwm/pwm-aspeed-ast2600.c new file mode 100644 index 000000000000..2c22aff18624 --- /dev/null +++ b/drivers/pwm/pwm-aspeed-ast2600.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2021 Aspeed Technology Inc. + * + * PWM controller driver for Aspeed ast2600 SoCs. + * This drivers doesn't support earlier version of the IP. + * + * The hardware operates in time quantities of length + * Q := (DIV_L + 1) << DIV_H / input-clk + * The length of a PWM period is (DUTY_CYCLE_PERIOD + 1) * Q. + * The maximal value for DUTY_CYCLE_PERIOD is used here to provide + * a fine grained selection for the duty cycle. + * + * This driver uses DUTY_CYCLE_RISING_POINT = 0, so from the start of a + * period the output is active until DUTY_CYCLE_FALLING_POINT * Q. Note + * that if DUTY_CYCLE_RISING_POINT = DUTY_CYCLE_FALLING_POINT the output is + * always active. + * + * Register usage: + * PIN_ENABLE: When it is unset the pwm controller will emit inactive level to the external. + * Use to determine whether the PWM channel is enabled or disabled + * CLK_ENABLE: When it is unset the pwm controller will assert the duty counter reset and + * emit inactive level to the PIN_ENABLE mux after that the driver can still change the pwm period + * and duty and the value will apply when CLK_ENABLE be set again. + * Use to determine whether duty_cycle bigger than 0. + * PWM_ASPEED_CTRL_INVERSE: When it is toggled the output value will inverse immediately. + * PWM_ASPEED_DUTY_CYCLE_FALLING_POINT/PWM_ASPEED_DUTY_CYCLE_RISING_POINT: When these two + * values are equal it means the duty cycle = 100%. + * + * The glitch may generate at: + * - Enabled changing when the duty_cycle bigger than 0% and less than 100%. + * - Polarity changing when the duty_cycle bigger than 0% and less than 100%. + * + * Limitations: + * - When changing both duty cycle and period, we cannot prevent in + * software that the output might produce a period with mixed + * settings. + * - Disabling the PWM doesn't complete the current period. + * + * Improvements: + * - When only changing one of duty cycle or period, our pwm controller will not + * generate the glitch, the configure will change at next cycle of pwm. + * This improvement can disable/enable through PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE. + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/math64.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/regmap.h> +#include <linux/reset.h> +#include <linux/sysfs.h> + +/* The channel number of Aspeed pwm controller */ +#define PWM_ASPEED_NR_PWMS 16 +/* PWM Control Register */ +#define PWM_ASPEED_CTRL(ch) ((ch) * 0x10 + 0x00) +#define PWM_ASPEED_CTRL_LOAD_SEL_RISING_AS_WDT BIT(19) +#define PWM_ASPEED_CTRL_DUTY_LOAD_AS_WDT_ENABLE BIT(18) +#define PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE BIT(17) +#define PWM_ASPEED_CTRL_CLK_ENABLE BIT(16) +#define PWM_ASPEED_CTRL_LEVEL_OUTPUT BIT(15) +#define PWM_ASPEED_CTRL_INVERSE BIT(14) +#define PWM_ASPEED_CTRL_OPEN_DRAIN_ENABLE BIT(13) +#define PWM_ASPEED_CTRL_PIN_ENABLE BIT(12) +#define PWM_ASPEED_CTRL_CLK_DIV_H GENMASK(11, 8) +#define PWM_ASPEED_CTRL_CLK_DIV_L GENMASK(7, 0) + +/* PWM Duty Cycle Register */ +#define PWM_ASPEED_DUTY_CYCLE(ch) ((ch) * 0x10 + 0x04) +#define PWM_ASPEED_DUTY_CYCLE_PERIOD GENMASK(31, 24) +#define PWM_ASPEED_DUTY_CYCLE_POINT_AS_WDT GENMASK(23, 16) +#define PWM_ASPEED_DUTY_CYCLE_FALLING_POINT GENMASK(15, 8) +#define PWM_ASPEED_DUTY_CYCLE_RISING_POINT GENMASK(7, 0) + +/* PWM fixed value */ +#define PWM_ASPEED_FIXED_PERIOD FIELD_MAX(PWM_ASPEED_DUTY_CYCLE_PERIOD) + +struct aspeed_pwm_data { + struct pwm_chip chip; + struct clk *clk; + struct regmap *regmap; + struct reset_control *reset; +}; + +static inline struct aspeed_pwm_data * +aspeed_pwm_chip_to_data(struct pwm_chip *chip) +{ + return container_of(chip, struct aspeed_pwm_data, chip); +} + +static void aspeed_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct device *dev = chip->dev; + struct aspeed_pwm_data *priv = aspeed_pwm_chip_to_data(chip); + u32 hwpwm = pwm->hwpwm; + bool polarity, pin_en, clk_en; + u32 duty_pt, val; + unsigned long rate; + u64 div_h, div_l, duty_cycle_period, dividend; + + regmap_read(priv->regmap, PWM_ASPEED_CTRL(hwpwm), &val); + polarity = FIELD_GET(PWM_ASPEED_CTRL_INVERSE, val); + pin_en = FIELD_GET(PWM_ASPEED_CTRL_PIN_ENABLE, val); + clk_en = FIELD_GET(PWM_ASPEED_CTRL_CLK_ENABLE, val); + div_h = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_H, val); + div_l = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_L, val); + regmap_read(priv->regmap, PWM_ASPEED_DUTY_CYCLE(hwpwm), &val); + duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val); + duty_cycle_period = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_PERIOD, val); + + rate = clk_get_rate(priv->clk); + + /* + * This multiplication doesn't overflow, the upper bound is + * 1000000000 * 256 * 256 << 15 = 0x1dcd650000000000 + */ + dividend = (u64)NSEC_PER_SEC * (div_l + 1) * (duty_cycle_period + 1) + << div_h; + state->period = DIV_ROUND_UP_ULL(dividend, rate); + + if (clk_en && duty_pt) { + dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt + << div_h; + state->duty_cycle = DIV_ROUND_UP_ULL(dividend, rate); + } else { + state->duty_cycle = clk_en ? state->period : 0; + } + state->polarity = polarity ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL; + state->enabled = pin_en; + dev_dbg(dev, "get period: %lldns, duty_cycle: %lldns", state->period, + state->duty_cycle); +} + +static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct device *dev = chip->dev; + struct aspeed_pwm_data *priv = aspeed_pwm_chip_to_data(chip); + u32 hwpwm = pwm->hwpwm, duty_pt; + unsigned long rate; + u64 div_h, div_l, divisor, expect_period; + bool clk_en; + + rate = clk_get_rate(priv->clk); + expect_period = min(div64_u64(ULLONG_MAX, (u64)rate), state->period); + dev_dbg(dev, "expect period: %lldns, duty_cycle: %lldns", expect_period, + state->duty_cycle); + /* + * Pick the smallest value for div_h so that div_l can be the biggest + * which results in a finer resolution near the target period value. + */ + divisor = (u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1) * + (FIELD_MAX(PWM_ASPEED_CTRL_CLK_DIV_L) + 1); + div_h = order_base_2(DIV64_U64_ROUND_UP(rate * expect_period, divisor)); + if (div_h > 0xf) + div_h = 0xf; + + divisor = ((u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1)) << div_h; + div_l = div64_u64(rate * expect_period, divisor); + + if (div_l == 0) + return -ERANGE; + + div_l -= 1; + + if (div_l > 255) + div_l = 255; + + dev_dbg(dev, "clk source: %ld div_h %lld, div_l : %lld\n", rate, div_h, + div_l); + /* duty_pt = duty_cycle * (PERIOD + 1) / period */ + duty_pt = div64_u64(state->duty_cycle * rate, + (u64)NSEC_PER_SEC * (div_l + 1) << div_h); + dev_dbg(dev, "duty_cycle = %lld, duty_pt = %d\n", state->duty_cycle, + duty_pt); + + /* + * Fixed DUTY_CYCLE_PERIOD to its max value to get a + * fine-grained resolution for duty_cycle at the expense of a + * coarser period resolution. + */ + regmap_update_bits(priv->regmap, PWM_ASPEED_DUTY_CYCLE(hwpwm), + PWM_ASPEED_DUTY_CYCLE_PERIOD, + FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_PERIOD, + PWM_ASPEED_FIXED_PERIOD)); + if (duty_pt == 0) { + /* emit inactive level and assert the duty counter reset */ + clk_en = 0; + } else { + clk_en = 1; + if (duty_pt >= (PWM_ASPEED_FIXED_PERIOD + 1)) + duty_pt = 0; + regmap_update_bits(priv->regmap, PWM_ASPEED_DUTY_CYCLE(hwpwm), + PWM_ASPEED_DUTY_CYCLE_RISING_POINT | + PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, + FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt)); + } + + regmap_update_bits(priv->regmap, PWM_ASPEED_CTRL(hwpwm), + PWM_ASPEED_CTRL_CLK_DIV_H | PWM_ASPEED_CTRL_CLK_DIV_L | + PWM_ASPEED_CTRL_PIN_ENABLE | PWM_ASPEED_CTRL_CLK_ENABLE | + PWM_ASPEED_CTRL_INVERSE, + FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_H, div_h) | + FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_L, div_l) | + FIELD_PREP(PWM_ASPEED_CTRL_PIN_ENABLE, state->enabled) | + FIELD_PREP(PWM_ASPEED_CTRL_CLK_ENABLE, clk_en) | + FIELD_PREP(PWM_ASPEED_CTRL_INVERSE, state->polarity)); + return 0; +} + +static const struct pwm_ops aspeed_pwm_ops = { + .apply = aspeed_pwm_apply, + .get_state = aspeed_pwm_get_state, + .owner = THIS_MODULE, +}; + +static void aspeed_pwm_reset_assert(void *data) +{ + struct reset_control *rst = data; + + reset_control_assert(rst); +} + +static void aspeed_pwm_chip_remove(void *data) +{ + struct pwm_chip *chip = data; + + pwmchip_remove(chip); +} + +static int aspeed_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int ret; + struct aspeed_pwm_data *priv; + struct device_node *np; + struct platform_device *parent_dev; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + np = pdev->dev.parent->of_node; + if (!of_device_is_compatible(np, "aspeed,ast2600-pwm-tach")) + return dev_err_probe(dev, -ENODEV, + "Unsupported pwm device binding\n"); + + priv->regmap = syscon_node_to_regmap(np); + if (IS_ERR(priv->regmap)) + return dev_err_probe(dev, PTR_ERR(priv->regmap), + "Couldn't get regmap\n"); + + parent_dev = of_find_device_by_node(np); + priv->clk = devm_clk_get_enabled(&parent_dev->dev, NULL); + if (IS_ERR(priv->clk)) + return dev_err_probe(dev, PTR_ERR(priv->clk), + "Couldn't get clock\n"); + + priv->reset = devm_reset_control_get_shared(&parent_dev->dev, NULL); + if (IS_ERR(priv->reset)) + return dev_err_probe(dev, PTR_ERR(priv->reset), + "Couldn't get reset control\n"); + + ret = reset_control_deassert(priv->reset); + if (ret) + return dev_err_probe(dev, ret, + "Couldn't deassert reset control\n"); + + ret = devm_add_action_or_reset(dev, aspeed_pwm_reset_assert, + priv->reset); + if (ret) + return ret; + + priv->chip.dev = dev; + priv->chip.ops = &aspeed_pwm_ops; + priv->chip.npwm = PWM_ASPEED_NR_PWMS; + + ret = pwmchip_add(&priv->chip); + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to add PWM chip\n"); + ret = devm_add_action_or_reset(dev, aspeed_pwm_chip_remove, + &priv->chip); + if (ret) + return ret; + return 0; +} + +static const struct of_device_id of_pwm_match_table[] = { + { + .compatible = "aspeed,ast2600-pwm", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_pwm_match_table); + +static struct platform_driver aspeed_pwm_driver = { + .probe = aspeed_pwm_probe, + .driver = { + .name = "aspeed-pwm", + .of_match_table = of_pwm_match_table, + }, +}; + +module_platform_driver(aspeed_pwm_driver); + +MODULE_AUTHOR("Billy Tsai <billy_tsai@aspeedtech.com>"); +MODULE_DESCRIPTION("Aspeed ast2600 PWM device driver"); +MODULE_LICENSE("GPL");