* [U-Boot] [PATCH v3 1/2] pwm: sunxi: add support for PWM found on Allwinner A64
2018-04-28 21:05 [U-Boot] [PATCH v3 0/2] sunxi: add PWM driver for A64 Vasily Khoruzhick
@ 2018-04-28 21:05 ` Vasily Khoruzhick
2018-05-02 9:24 ` Maxime Ripard
2018-04-28 21:05 ` [U-Boot] [PATCH v3 2/2] dts: sunxi: add PWM node for sun50i Vasily Khoruzhick
1 sibling, 1 reply; 5+ messages in thread
From: Vasily Khoruzhick @ 2018-04-28 21:05 UTC (permalink / raw)
To: u-boot
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(®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;
+ u32 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;
+ }
+
+ 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, ®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)
+{
+ 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),
+};
--
2.17.0
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