This commit adds basic support for PWM found on Allwinner A64. It can be used for pwm_backlight driver (e.g. for Pinebook)

Signed-off-by: Vasily Khoruzhick anarsoul@gmail.com --- arch/arm/include/asm/arch-sunxi/gpio.h | 1 + arch/arm/include/asm/arch-sunxi/pwm.h | 12 ++ drivers/pwm/Kconfig | 7 + drivers/pwm/Makefile | 1 + drivers/pwm/sunxi_pwm.c | 178 +++++++++++++++++++++++++ 5 files changed, 199 insertions(+) create mode 100644 drivers/pwm/sunxi_pwm.c

diff --git a/arch/arm/include/asm/arch-sunxi/gpio.h b/arch/arm/include/asm/arch-sunxi/gpio.h index 24f85206c8..7265d18099 100644 --- a/arch/arm/include/asm/arch-sunxi/gpio.h +++ b/arch/arm/include/asm/arch-sunxi/gpio.h @@ -173,6 +173,7 @@ enum sunxi_gpio_number { #define SUN8I_GPD_SDC1 3 #define SUNXI_GPD_LCD0 2 #define SUNXI_GPD_LVDS0 3 +#define SUNXI_GPD_PWM 2

#define SUN5I_GPE_SDC2 3 #define SUN8I_GPE_TWI2 3 diff --git a/arch/arm/include/asm/arch-sunxi/pwm.h b/arch/arm/include/asm/arch-sunxi/pwm.h index 5884b5dbe7..e9368f2fb8 100644 --- a/arch/arm/include/asm/arch-sunxi/pwm.h +++ b/arch/arm/include/asm/arch-sunxi/pwm.h @@ -11,8 +11,15 @@ #define SUNXI_PWM_CH0_PERIOD (SUNXI_PWM_BASE + 4)

#define SUNXI_PWM_CTRL_PRESCALE0(x) ((x) & 0xf) +#define SUNXI_PWM_CTRL_PRESCALE0_MASK 0xf #define SUNXI_PWM_CTRL_ENABLE0 (0x5 << 4) #define SUNXI_PWM_CTRL_POLARITY0(x) ((x) << 5) +#define SUNXI_PWM_CTRL_CH0_ACT_STA BIT(5) +#define SUNXI_PWM_CTRL_CLK_GATE BIT(6) + +#define SUNXI_PWM_CH0_PERIOD_MAX (0xffff) +#define SUNXI_PWM_CH0_PERIOD_PRD(x) ((x & 0xffff) << 16) +#define SUNXI_PWM_CH0_PERIOD_DUTY(x) ((x) & 0xffff)

#define SUNXI_PWM_PERIOD_80PCT 0x04af03c0

@@ -31,4 +38,9 @@ #define SUNXI_PWM_MUX SUN8I_GPH_PWM #endif

+struct sunxi_pwm { + u32 ctrl; + u32 ch0_period; +}; + #endif diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index e827558052..2984b79766 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -43,3 +43,10 @@ config PWM_TEGRA four channels with a programmable period and duty cycle. Only a 32KHz clock is supported by the driver but the duty cycle is configurable. + +config PWM_SUNXI + bool "Enable support for the Allwinner Sunxi PWM" + depends on DM_PWM + help + This PWM is found on H3, A64 and other Allwinner SoCs. It supports a + programmable period and duty cycle. A 16-bit counter is used. diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 29d59916cb..1a8f8a58bc 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o obj-$(CONFIG_PWM_ROCKCHIP) += rk_pwm.o obj-$(CONFIG_PWM_SANDBOX) += sandbox_pwm.o obj-$(CONFIG_PWM_TEGRA) += tegra_pwm.o +obj-$(CONFIG_PWM_SUNXI) += sunxi_pwm.o diff --git a/drivers/pwm/sunxi_pwm.c b/drivers/pwm/sunxi_pwm.c new file mode 100644 index 0000000000..8e7ba347a7 --- /dev/null +++ b/drivers/pwm/sunxi_pwm.c @@ -0,0 +1,178 @@ +/* + * Copyright (c) 2017-2018 Vasily Khoruzhick anarsoul@gmail.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <div64.h> +#include <dm.h> +#include <pwm.h> +#include <regmap.h> +#include <syscon.h> +#include <asm/io.h> +#include <asm/arch/pwm.h> +#include <asm/arch/gpio.h> +#include <power/regulator.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define OSC_24MHZ 24000000 + +struct sunxi_pwm_priv { + struct sunxi_pwm *regs; + bool invert; + u32 prescaler; +}; + +static const u32 prescaler_table[] = { + 120, /* 0000 */ + 180, /* 0001 */ + 240, /* 0010 */ + 360, /* 0011 */ + 480, /* 0100 */ + 0, /* 0101 */ + 0, /* 0110 */ + 0, /* 0111 */ + 12000, /* 1000 */ + 24000, /* 1001 */ + 36000, /* 1010 */ + 48000, /* 1011 */ + 72000, /* 1100 */ + 0, /* 1101 */ + 0, /* 1110 */ + 1, /* 1111 */ +}; + +static int sunxi_pwm_config_pinmux(void) +{ +#ifdef CONFIG_MACH_SUN50I + sunxi_gpio_set_cfgpin(SUNXI_GPD(22), SUNXI_GPD_PWM); +#endif + return 0; +} + +static int sunxi_pwm_set_invert(struct udevice *dev, uint channel, + bool polarity) +{ + struct sunxi_pwm_priv *priv = dev_get_priv(dev); + + debug("%s: polarity=%u\n", __func__, polarity); + priv->invert = polarity; + + return 0; +} + +static int sunxi_pwm_set_config(struct udevice *dev, uint channel, + uint period_ns, uint duty_ns) +{ + struct sunxi_pwm_priv *priv = dev_get_priv(dev); + struct sunxi_pwm *regs = priv->regs; + int prescaler; + u32 v, period = 0, duty; + u64 scaled_freq = 0; + const u32 nsecs_per_sec = 1000000000U; + + debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns); + + for (prescaler = 0; prescaler < SUNXI_PWM_CTRL_PRESCALE0_MASK; + prescaler++) { + if (!prescaler_table[prescaler]) + continue; + scaled_freq = lldiv(OSC_24MHZ, prescaler_table[prescaler]); + period = lldiv(scaled_freq * period_ns, nsecs_per_sec); + if (period - 1 <= SUNXI_PWM_CH0_PERIOD_MAX) + break; + } + + if (period - 1 > SUNXI_PWM_CH0_PERIOD_MAX) { + debug("%s: failed to find prescaler value\n", __func__); + return -EINVAL; + } + + duty = lldiv(scaled_freq * duty_ns, nsecs_per_sec); + + if (priv->prescaler != prescaler) { + /* Mask clock to update prescaler */ + v = readl(&regs->ctrl); + v &= ~SUNXI_PWM_CTRL_CLK_GATE; + writel(v, &regs->ctrl); + v &= ~SUNXI_PWM_CTRL_PRESCALE0_MASK; + v |= (priv->prescaler & SUNXI_PWM_CTRL_PRESCALE0_MASK); + writel(v, &regs->ctrl); + v |= SUNXI_PWM_CTRL_CLK_GATE; + writel(v, &regs->ctrl); + priv->prescaler = prescaler; + } + + writel(SUNXI_PWM_CH0_PERIOD_PRD(period) | + SUNXI_PWM_CH0_PERIOD_DUTY(duty), &regs->ch0_period); + + debug("%s: prescaler: %d, period: %d, duty: %d\n", + __func__, priv->prescaler, + period, duty); + + return 0; +} + +static int sunxi_pwm_set_enable(struct udevice *dev, uint channel, bool enable) +{ + struct sunxi_pwm_priv *priv = dev_get_priv(dev); + struct sunxi_pwm *regs = priv->regs; + u32 v; + + debug("%s: Enable '%s'\n", __func__, dev->name); + + v = readl(&regs->ctrl); + if (!enable) { + v &= ~SUNXI_PWM_CTRL_ENABLE0; + writel(v, &regs->ctrl); + return 0; + } + + sunxi_pwm_config_pinmux(); + + if (priv->invert) + v &= ~SUNXI_PWM_CTRL_CH0_ACT_STA; + else + v |= SUNXI_PWM_CTRL_CH0_ACT_STA; + v |= SUNXI_PWM_CTRL_ENABLE0; + writel(v, &regs->ctrl); + + return 0; +} + +static int sunxi_pwm_ofdata_to_platdata(struct udevice *dev) +{ + struct sunxi_pwm_priv *priv = dev_get_priv(dev); + + priv->regs = (struct sunxi_pwm *)devfdt_get_addr(dev); + + return 0; +} + +static int sunxi_pwm_probe(struct udevice *dev) +{ + return 0; +} + +static const struct pwm_ops sunxi_pwm_ops = { + .set_invert = sunxi_pwm_set_invert, + .set_config = sunxi_pwm_set_config, + .set_enable = sunxi_pwm_set_enable, +}; + +static const struct udevice_id sunxi_pwm_ids[] = { + { .compatible = "allwinner,sun50i-a64-pwm" }, + { } +}; + +U_BOOT_DRIVER(sunxi_pwm) = { + .name = "sunxi_pwm", + .id = UCLASS_PWM, + .of_match = sunxi_pwm_ids, + .ops = &sunxi_pwm_ops, + .ofdata_to_platdata = sunxi_pwm_ofdata_to_platdata, + .probe = sunxi_pwm_probe, + .priv_auto_alloc_size = sizeof(struct sunxi_pwm_priv), +};