[U-Boot] [RESEND PATCH 1/3] pwm: sunxi: add support for PWM found on Allwinner A64 and H3
Andre Przywara
andre.przywara at arm.com
Tue Sep 19 08:51:32 UTC 2017
Hi,
On 19/09/17 06:06, Vasily Khoruzhick wrote:
> This commit adds basic support for PWM found on Allwinner A64 and H3
Mmh, can you explain (for instance in a 0/3 email) what this is used
for? My understanding is that PWM0 (which is what you hard code here) is
only exposed on PD22, which is also used for the MDC line to the
Ethernet PHY. All boards I heard of have Ethernet, so PWM0 is not usable
there.
So is this for a special board?
>
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> ---
> arch/arm/include/asm/arch-sunxi/gpio.h | 1 +
> arch/arm/include/asm/arch-sunxi/pwm.h | 12 +++
> arch/arm/mach-sunxi/board.c | 11 +++
> drivers/pwm/Kconfig | 7 ++
> drivers/pwm/Makefile | 1 +
> drivers/pwm/sunxi_pwm.c | 174 +++++++++++++++++++++++++++++++++
> 6 files changed, 206 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..673e0eb7b5 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_POLARITY0_MASK (1 << 5)
> +#define SUNXI_PWM_CTRL_CLK_GATE (1 << 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/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c
> index 65b1ebd837..a85f973a46 100644
> --- a/arch/arm/mach-sunxi/board.c
> +++ b/arch/arm/mach-sunxi/board.c
> @@ -141,6 +141,16 @@ static int gpio_init(void)
> return 0;
> }
>
> +static int pwm_init(void)
> +{
> +#ifdef CONFIG_PWM_SUNXI
> +#ifdef CONFIG_MACH_SUN50I
> + sunxi_gpio_set_cfgpin(SUNXI_GPD(22), SUNXI_GPD_PWM);
So this would probably kill Ethernet.
At the very least this should be somehow protected against this clash.
And I wonder if this should move into the PWM driver, for instance into
the .enable function.
Cheers,
Andre.
> +#endif
> +#endif
> + return 0;
> +}
> +
> #if defined(CONFIG_SPL_BOARD_LOAD_IMAGE) && defined(CONFIG_SPL_BUILD)
> static int spl_board_load_image(struct spl_image_info *spl_image,
> struct spl_boot_device *bootdev)
> @@ -204,6 +214,7 @@ void s_init(void)
> clock_init();
> timer_init();
> gpio_init();
> + pwm_init();
> #ifndef CONFIG_DM_I2C
> i2c_init_board();
> #endif
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index e827558052..67e3f355e7 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 A64 and other Allwinner SoCs. It supports a
> + programmable period and duty cycle. A 32-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..3e6d69fa1c
> --- /dev/null
> +++ b/drivers/pwm/sunxi_pwm.c
> @@ -0,0 +1,174 @@
> +/*
> + * Copyright (c) 2017 Vasily Khoruzhick <anarsoul at 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 <power/regulator.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +struct sunxi_pwm_priv {
> + struct sunxi_pwm *regs;
> + ulong freq;
> + bool invert;
> + uint32_t prescaler;
> +};
> +
> +static const uint32_t 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 const uint64_t nsecs_per_sec = 1000000000L;
> +
> +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, duty;
> + uint64_t div = 0, pval = 0, scaled_freq = 0;
> +
> + 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;
> + div = priv->freq;
> + pval = prescaler_table[prescaler];
> + scaled_freq = lldiv(div, pval);
> + div = scaled_freq * period_ns;
> + div = lldiv(div, nsecs_per_sec);
> + if (div - 1 <= SUNXI_PWM_CH0_PERIOD_MAX)
> + break;
> + }
> +
> + if (div - 1 > SUNXI_PWM_CH0_PERIOD_MAX) {
> + debug("%s: failed to find prescaler value\n", __func__);
> + return -EINVAL;
> + }
> +
> + period = div;
> + div = scaled_freq * duty_ns;
> + div = lldiv(div, nsecs_per_sec);
> + duty = div;
> +
> + if (priv->prescaler != prescaler) {
> + /* Mask clock to update prescaler */
> + v = readl(®s->ctrl);
> + v &= ~SUNXI_PWM_CTRL_CLK_GATE;
> + writel(v, ®s->ctrl);
> + v &= ~SUNXI_PWM_CTRL_PRESCALE0_MASK;
> + v |= (priv->prescaler & SUNXI_PWM_CTRL_PRESCALE0_MASK);
> + writel(v, ®s->ctrl);
> + v |= SUNXI_PWM_CTRL_CLK_GATE;
> + writel(v, ®s->ctrl);
> + priv->prescaler = prescaler;
> + }
> +
> + writel(SUNXI_PWM_CH0_PERIOD_PRD(period) |
> + SUNXI_PWM_CH0_PERIOD_DUTY(duty), ®s->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;
> + uint32_t v;
> +
> + debug("%s: Enable '%s'\n", __func__, dev->name);
> +
> + v = readl(®s->ctrl);
> + if (!enable) {
> + v &= ~SUNXI_PWM_CTRL_ENABLE0;
> + writel(v, ®s->ctrl);
> + return 0;
> + }
> +
> + v &= ~SUNXI_PWM_CTRL_POLARITY0_MASK;
> + v |= priv->invert ? SUNXI_PWM_CTRL_POLARITY0(0) :
> + SUNXI_PWM_CTRL_POLARITY0(1);
> + v |= SUNXI_PWM_CTRL_ENABLE0;
> + writel(v, ®s->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)
> +{
> + struct sunxi_pwm_priv *priv = dev_get_priv(dev);
> +
> + priv->freq = 24000000;
> +
> + 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,sun8i-h3-pwm" },
> + { .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),
> +};
>
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