armbian-build/patch/kernel/mvebu-default/90-gpio-mvebu-Add-limited-PWM-support.patch.disabled
2017-11-01 18:09:00 +03:00

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From 65bce3cd01230b283915be86196f5e1318c18dd6 Mon Sep 17 00:00:00 2001
From: aprayoga <adit.prayoga@gmail.com>
Date: Sun, 3 Sep 2017 15:59:11 +0800
Subject: gpio: mvebu: Add limited PWM support
backported from https://patchwork.kernel.org/patch/9681399/
* Remove atomic PWM API portion as this is not supported on LK4.4
and use https://patchwork.ozlabs.org/patch/739591/ instead.
---
.../devicetree/bindings/gpio/gpio-mvebu.txt | 31 +++
MAINTAINERS | 2 +
drivers/gpio/gpio-mvebu.c | 309 ++++++++++++++++++++-
3 files changed, 328 insertions(+), 14 deletions(-)
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
index 6b76891..b6cdcb2 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
@@ -46,6 +46,23 @@ Optional:
The base of CP0 bank0 should be 20 (after AP-806 pins) the base of CP0 bank1 should be
52 (after AP-806, and CP0 bank0 pins)
+Optional properties:
+
+In order to use the gpio lines in PWM mode, some additional optional
+properties are required. Only Armada 370 and XP support these properties.
+
+- reg: an additional register set is needed, for the GPIO Blink
+ Counter on/off registers.
+
+- reg-names: Must contain an entry "pwm" corresponding to the
+ additional register range needed for pwm operation.
+
+- #pwm-cells: Should be two. The first cell is the pin number. The
+ second cell is reserved for flags and should be set to 0, so it has a
+ known value. It then becomes possible to use it in the future.
+
+- clocks: Must be a phandle to the clock for the gpio controller.
+
Example:
gpio0: gpio@d0018100 {
@@ -59,3 +76,17 @@ Example:
#interrupt-cells = <2>;
interrupts = <16>, <17>, <18>, <19>;
};
+
+ gpio1: gpio@18140 {
+ compatible = "marvell,armada-370-xp-gpio";
+ reg = <0x18140 0x40>, <0x181c8 0x08>;
+ reg-names = "gpio", "pwm";
+ ngpios = <17>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ #pwm-cells = <2>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ interrupts = <87>, <88>, <89>;
+ clocks = <&coreclk 0>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 7008b0d..d272aca 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8635,6 +8635,8 @@ F: include/linux/pwm.h
F: drivers/pwm/
F: drivers/video/backlight/pwm_bl.c
F: include/linux/pwm_backlight.h
+F: drivers/gpio/gpio-mvebu.c
+F: Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
PXA2xx/PXA3xx SUPPORT
M: Daniel Mack <daniel@zonque.org>
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index ffea532..8775123 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -42,29 +42,43 @@
#include <linux/io.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>
+#include <linux/pwm.h>
#include <linux/clk.h>
#include <linux/pinctrl/consumer.h>
#include <linux/irqchip/chained_irq.h>
+#include <linux/platform_device.h>
+
+#include "gpiolib.h"
/*
* GPIO unit register offsets.
*/
-#define GPIO_OUT_OFF 0x0000
-#define GPIO_IO_CONF_OFF 0x0004
-#define GPIO_BLINK_EN_OFF 0x0008
-#define GPIO_IN_POL_OFF 0x000c
-#define GPIO_DATA_IN_OFF 0x0010
-#define GPIO_EDGE_CAUSE_OFF 0x0014
-#define GPIO_EDGE_MASK_OFF 0x0018
-#define GPIO_LEVEL_MASK_OFF 0x001c
+#define GPIO_OUT_OFF 0x0000
+#define GPIO_IO_CONF_OFF 0x0004
+#define GPIO_BLINK_EN_OFF 0x0008
+#define GPIO_IN_POL_OFF 0x000c
+#define GPIO_DATA_IN_OFF 0x0010
+#define GPIO_EDGE_CAUSE_OFF 0x0014
+#define GPIO_EDGE_MASK_OFF 0x0018
+#define GPIO_LEVEL_MASK_OFF 0x001c
+#define GPIO_BLINK_CNT_SELECT_OFF 0x0020
+
+/*
+ * PWM register offsets.
+ */
+#define PWM_BLINK_ON_DURATION_OFF 0x0
+#define PWM_BLINK_OFF_DURATION_OFF 0x4
+
/* The MV78200 has per-CPU registers for edge mask and level mask */
#define GPIO_EDGE_MASK_MV78200_OFF(cpu) ((cpu) ? 0x30 : 0x18)
#define GPIO_LEVEL_MASK_MV78200_OFF(cpu) ((cpu) ? 0x34 : 0x1C)
-/* The Armada XP has per-CPU registers for interrupt cause, interrupt
+/*
+ * The Armada XP has per-CPU registers for interrupt cause, interrupt
* mask and interrupt level mask. Those are relative to the
- * percpu_membase. */
+ * percpu_membase.
+ */
#define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
#define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu) (0x10 + (cpu) * 0x4)
#define GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu) (0x20 + (cpu) * 0x4)
@@ -75,6 +89,23 @@
#define MVEBU_MAX_GPIO_PER_BANK 32
+struct mvebu_pwm {
+ void __iomem *membase;
+ unsigned long clk_rate;
+ struct gpio_desc *gpiod;
+ bool used;
+ unsigned int pin;
+ struct pwm_chip chip;
+ int id;
+ spinlock_t lock;
+ struct mvebu_gpio_chip *mvchip;
+
+ /* Used to preserve GPIO/PWM registers across suspend/resume */
+ u32 blink_select;
+ u32 blink_on_duration;
+ u32 blink_off_duration;
+};
+
struct mvebu_gpio_chip {
struct gpio_chip chip;
spinlock_t lock;
@@ -84,6 +115,10 @@ struct mvebu_gpio_chip {
struct irq_domain *domain;
int soc_variant;
+ /* Used for PWM support */
+ struct clk *clk;
+ struct mvebu_pwm *mvpwm;
+
/* Used to preserve GPIO registers across suspend/resume */
u32 out_reg;
u32 io_conf_reg;
@@ -102,6 +137,11 @@ static inline void __iomem *mvebu_gpioreg_out(struct mvebu_gpio_chip *mvchip)
return mvchip->membase + GPIO_OUT_OFF;
}
+static void __iomem *mvebu_gpioreg_blink_select(struct mvebu_gpio_chip *mvchip)
+{
+ return mvchip->membase + GPIO_BLINK_CNT_SELECT_OFF;
+}
+
static inline void __iomem *mvebu_gpioreg_blink(struct mvebu_gpio_chip *mvchip)
{
return mvchip->membase + GPIO_BLINK_EN_OFF;
@@ -182,6 +222,20 @@ static void __iomem *mvebu_gpioreg_level_mask(struct mvebu_gpio_chip *mvchip)
}
/*
+ * Functions returning addresses of individual registers for a given
+ * PWM controller.
+ */
+static void __iomem *mvebu_pwmreg_blink_on_duration(struct mvebu_pwm *mvpwm)
+{
+ return mvpwm->membase + PWM_BLINK_ON_DURATION_OFF;
+}
+
+static void __iomem *mvebu_pwmreg_blink_off_duration(struct mvebu_pwm *mvpwm)
+{
+ return mvpwm->membase + PWM_BLINK_OFF_DURATION_OFF;
+}
+
+/*
* Functions implementing the gpio_chip methods
*/
@@ -489,6 +543,220 @@ static void mvebu_gpio_irq_handler(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}
+/*
+ * Functions implementing the pwm_chip methods
+ */
+static struct mvebu_pwm *to_mvebu_pwm(struct pwm_chip *chip)
+{
+ return container_of(chip, struct mvebu_pwm, chip);
+}
+
+static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+ struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+ struct gpio_desc *desc;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&mvpwm->lock, flags);
+ if (mvpwm->gpiod) {
+ ret = -EBUSY;
+ } else {
+ desc = gpio_to_desc(mvchip->chip.base + pwm->hwpwm);
+ if (!desc) {
+ ret = -ENODEV;
+ goto out;
+ }
+ ret = gpiod_request(desc, "mvebu-pwm");
+ if (ret)
+ goto out;
+
+ ret = gpiod_direction_output(desc, 0);
+ if (ret) {
+ gpiod_free(desc);
+ goto out;
+ }
+
+ mvpwm->gpiod = desc;
+ mvpwm->pin = pwm->pwm - mvchip->chip.base;
+ mvpwm->used = true;
+ }
+
+out:
+ spin_unlock_irqrestore(&mvpwm->lock, flags);
+ return ret;
+}
+
+static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mvpwm->lock, flags);
+ gpiod_free(mvpwm->gpiod);
+ mvpwm->used = false;
+ spin_unlock_irqrestore(&mvpwm->lock, flags);
+}
+
+static int mvebu_pwm_config(struct pwm_chip *chip, struct pwm_device *pwmd,
+ int duty_ns, int period_ns)
+{
+ struct mvebu_pwm *pwm = to_mvebu_pwm(chip);
+ struct mvebu_gpio_chip *mvchip = pwm->mvchip;
+ unsigned int on, off;
+ unsigned long long val;
+ u32 u;
+
+ val = (unsigned long long) pwm->clk_rate * duty_ns;
+ do_div(val, NSEC_PER_SEC);
+ if (val > UINT_MAX)
+ return -EINVAL;
+ if (val)
+ on = val;
+ else
+ on = 1;
+
+ val = (unsigned long long) pwm->clk_rate * (period_ns - duty_ns);
+ do_div(val, NSEC_PER_SEC);
+ if (val > UINT_MAX)
+ return -EINVAL;
+ if (val)
+ off = val;
+ else
+ off = 1;
+
+ u = readl_relaxed(mvebu_gpioreg_blink_select(mvchip));
+ u &= ~(1 << pwm->pin);
+ u |= (pwm->id << pwm->pin);
+ writel_relaxed(u, mvebu_gpioreg_blink_select(mvchip));
+
+ writel_relaxed(on, mvebu_pwmreg_blink_on_duration(pwm));
+ writel_relaxed(off, mvebu_pwmreg_blink_off_duration(pwm));
+
+ return 0;
+}
+
+static int mvebu_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+ struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+
+ mvebu_gpio_blink(&mvchip->chip, mvpwm->pin, 1);
+
+ return 0;
+}
+
+static void mvebu_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
+ struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
+
+ mvebu_gpio_blink(&mvchip->chip, mvpwm->pin, 0);
+}
+
+static const struct pwm_ops mvebu_pwm_ops = {
+ .request = mvebu_pwm_request,
+ .free = mvebu_pwm_free,
+ .config = mvebu_pwm_config,
+ .enable = mvebu_pwm_enable,
+ .disable = mvebu_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static void mvebu_pwm_suspend(struct mvebu_gpio_chip *mvchip)
+{
+ struct mvebu_pwm *mvpwm = mvchip->mvpwm;
+
+ mvpwm->blink_select =
+ readl_relaxed(mvebu_gpioreg_blink_select(mvchip));
+ mvpwm->blink_on_duration =
+ readl_relaxed(mvebu_pwmreg_blink_on_duration(mvpwm));
+ mvpwm->blink_off_duration =
+ readl_relaxed(mvebu_pwmreg_blink_off_duration(mvpwm));
+}
+
+static void mvebu_pwm_resume(struct mvebu_gpio_chip *mvchip)
+{
+ struct mvebu_pwm *mvpwm = mvchip->mvpwm;
+
+ writel_relaxed(mvpwm->blink_select,
+ mvebu_gpioreg_blink_select(mvchip));
+ writel_relaxed(mvpwm->blink_on_duration,
+ mvebu_pwmreg_blink_on_duration(mvpwm));
+ writel_relaxed(mvpwm->blink_off_duration,
+ mvebu_pwmreg_blink_off_duration(mvpwm));
+}
+
+/*
+ * Armada 370/XP has simple PWM support for gpio lines. Other SoCs
+ * don't have this hardware. So if we don't have the necessary
+ * resource, it is not an error.
+ */
+static int mvebu_pwm_probe(struct platform_device *pdev,
+ struct mvebu_gpio_chip *mvchip,
+ int id)
+{
+ struct device *dev = &pdev->dev;
+ struct mvebu_pwm *mvpwm;
+ struct resource *res;
+ u32 set;
+
+ if (!of_device_is_compatible(mvchip->chip.of_node,
+ "marvell,armada-370-xp-gpio"))
+ return 0;
+
+ if (IS_ERR(mvchip->clk))
+ return PTR_ERR(mvchip->clk);
+
+ /*
+ * There are only two sets of PWM configuration registers for
+ * all the GPIO lines on those SoCs which this driver reserves
+ * for the first two GPIO chips. So if the resource is missing
+ * we can't treat it as an error.
+ */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pwm");
+ if (!res)
+ return 0;
+
+ /*
+ * Use set A for lines of GPIO chip with id 0, B for GPIO chip
+ * with id 1. Don't allow further GPIO chips to be used for PWM.
+ */
+ if (id == 0)
+ set = 0;
+ else if (id == 1)
+ set = U32_MAX;
+ else
+ return -EINVAL;
+ writel_relaxed(set, mvebu_gpioreg_blink_select(mvchip));
+ mvpwm->id = id;
+
+ mvpwm = devm_kzalloc(dev, sizeof(struct mvebu_pwm), GFP_KERNEL);
+ if (!mvpwm)
+ return -ENOMEM;
+ mvchip->mvpwm = mvpwm;
+ mvpwm->mvchip = mvchip;
+
+ mvpwm->membase = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mvpwm->membase))
+ return PTR_ERR(mvpwm->membase);
+
+ mvpwm->clk_rate = clk_get_rate(mvchip->clk);
+ if (!mvpwm->clk_rate) {
+ dev_err(dev, "failed to get clock rate\n");
+ return -EINVAL;
+ }
+
+ mvpwm->chip.dev = dev;
+ mvpwm->chip.ops = &mvebu_pwm_ops;
+ mvpwm->chip.npwm = mvchip->chip.ngpio;
+
+ spin_lock_init(&mvpwm->lock);
+
+ return pwmchip_add(&mvpwm->chip);
+}
+
#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>
@@ -561,6 +829,10 @@ static const struct of_device_id mvebu_gpio_of_match[] = {
.data = (void *) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
},
{
+ .compatible = "marvell,armada-370-xp-gpio",
+ .data = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
+ },
+ {
/* sentinel */
},
};
@@ -607,6 +879,9 @@ static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
BUG();
}
+ if (IS_ENABLED(CONFIG_PWM))
+ mvebu_pwm_suspend(mvchip);
+
return 0;
}
@@ -650,6 +925,9 @@ static int mvebu_gpio_resume(struct platform_device *pdev)
BUG();
}
+ if (IS_ENABLED(CONFIG_PWM))
+ mvebu_pwm_resume(mvchip);
+
return 0;
}
@@ -661,7 +939,6 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
struct resource *res;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
- struct clk *clk;
unsigned int ngpios;
unsigned int gpio_base = -1;
int soc_variant;
@@ -695,10 +972,10 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
return id;
}
- clk = devm_clk_get(&pdev->dev, NULL);
+ mvchip->clk = devm_clk_get(&pdev->dev, NULL);
/* Not all SoCs require a clock.*/
- if (!IS_ERR(clk))
- clk_prepare_enable(clk);
+ if (!IS_ERR(mvchip->clk))
+ clk_prepare_enable(mvchip->clk);
mvchip->soc_variant = soc_variant;
mvchip->chip.label = dev_name(&pdev->dev);
@@ -835,6 +1112,10 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
goto err_generic_chip;
}
+ /* Armada 370/XP has simple PWM support for GPIO lines */
+ if (IS_ENABLED(CONFIG_PWM))
+ return mvebu_pwm_probe(pdev, mvchip, id);
+
return 0;
err_generic_chip:
--
2.7.4