ramips: add mt7628 pwm driver

Signed-off-by: John Crispin <blogic@openwrt.org>

Backport of r46953

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@47089 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 204 insertions, 0 deletions

diff --git a/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch b/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch
new file mode 100644
index 0000000000..4b82a7ef9e
--- /dev/null
+++ b/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch
@@ -0,0 +1,204 @@
+--- a/drivers/pwm/Kconfig
++++ b/drivers/pwm/Kconfig
+@@ -177,6 +177,15 @@
+ 	  To compile this driver as a module, choose M here: the module
+ 	  will be called pwm-lpss-platform.
+ 
++config PWM_MEDIATEK
++	tristate "Mediatek PWM support"
++	depends on RALINK && OF
++	help
++	  Generic PWM framework driver for Mediatek ARM SoC.
++
++	  To compile this driver as a module, choose M here: the module
++	  will be called pwm-mxs.
++
+ config PWM_MXS
+ 	tristate "Freescale MXS PWM support"
+ 	depends on ARCH_MXS && OF
+--- a/drivers/pwm/Makefile
++++ b/drivers/pwm/Makefile
+@@ -15,6 +15,7 @@
+ obj-$(CONFIG_PWM_LPSS)		+= pwm-lpss.o
+ obj-$(CONFIG_PWM_LPSS_PCI)	+= pwm-lpss-pci.o
+ obj-$(CONFIG_PWM_LPSS_PLATFORM)	+= pwm-lpss-platform.o
++obj-$(CONFIG_PWM_MEDIATEK)	+= pwm-mediatek.o
+ obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
+ obj-$(CONFIG_PWM_PCA9685)	+= pwm-pca9685.o
+ obj-$(CONFIG_PWM_PUV3)		+= pwm-puv3.o
+--- /dev/null
++++ b/drivers/pwm/pwm-mediatek.c
+@@ -0,0 +1,173 @@
++/*
++ * Mediatek Pulse Width Modulator driver
++ *
++ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
++ *
++ * This file is licensed under the terms of the GNU General Public
++ * License version 2. This program is licensed "as is" without any
++ * warranty of any kind, whether express or implied.
++ */
++
++#include <linux/err.h>
++#include <linux/io.h>
++#include <linux/ioport.h>
++#include <linux/kernel.h>
++#include <linux/module.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++#include <linux/pwm.h>
++#include <linux/slab.h>
++#include <linux/types.h>
++
++#define NUM_PWM		4
++
++/* PWM registers and bits definitions */
++#define PWMCON			0x00
++#define PWMHDUR			0x04
++#define PWMLDUR			0x08
++#define PWMGDUR			0x0c
++#define PWMWAVENUM		0x28
++#define PWMDWIDTH		0x2c
++#define PWMTHRES		0x30
++
++/**
++ * struct mtk_pwm_chip - struct representing pwm chip
++ *
++ * @mmio_base: base address of pwm chip
++ * @chip: linux pwm chip representation
++ */
++struct mtk_pwm_chip {
++	void __iomem *mmio_base;
++	struct pwm_chip chip;
++};
++
++static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip)
++{
++	return container_of(chip, struct mtk_pwm_chip, chip);
++}
++
++static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
++				  unsigned long offset)
++{
++	return ioread32(chip->mmio_base + 0x10 + (num * 0x40) + offset);
++}
++
++static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
++				    unsigned int num, unsigned long offset,
++				    unsigned long val)
++{
++	iowrite32(val, chip->mmio_base + 0x10 + (num * 0x40) + offset);
++}
++
++static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
++			    int duty_ns, int period_ns)
++{
++	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
++	u32 resolution = 100 / 4;
++	u32 clkdiv = 0;
++
++	while (period_ns / resolution  > 8191) {
++		clkdiv++;
++		resolution *= 2;
++	}
++
++	if (clkdiv > 7)
++		return -1;
++
++	mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv);
++	mtk_pwm_writel(pc, pwm->hwpwm, PWMDWIDTH, period_ns / resolution);
++	mtk_pwm_writel(pc, pwm->hwpwm, PWMTHRES, duty_ns / resolution);
++	return 0;
++}
++
++static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
++{
++	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
++	u32 val;
++
++	val = ioread32(pc->mmio_base);
++	val |= BIT(pwm->hwpwm);
++	iowrite32(val, pc->mmio_base);
++
++	return 0;
++}
++
++static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
++{
++	struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
++	u32 val;
++
++	val = ioread32(pc->mmio_base);
++	val &= ~BIT(pwm->hwpwm);
++	iowrite32(val, pc->mmio_base);
++}
++
++static const struct pwm_ops mtk_pwm_ops = {
++	.config = mtk_pwm_config,
++	.enable = mtk_pwm_enable,
++	.disable = mtk_pwm_disable,
++	.owner = THIS_MODULE,
++};
++
++static int mtk_pwm_probe(struct platform_device *pdev)
++{
++	struct mtk_pwm_chip *pc;
++	struct resource *r;
++	int ret;
++
++	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
++	if (!pc)
++		return -ENOMEM;
++
++	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
++	if (IS_ERR(pc->mmio_base))
++		return PTR_ERR(pc->mmio_base);
++
++	platform_set_drvdata(pdev, pc);
++
++	pc->chip.dev = &pdev->dev;
++	pc->chip.ops = &mtk_pwm_ops;
++	pc->chip.base = -1;
++	pc->chip.npwm = NUM_PWM;
++
++	ret = pwmchip_add(&pc->chip);
++	if (ret < 0)
++		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
++
++	return ret;
++}
++
++static int mtk_pwm_remove(struct platform_device *pdev)
++{
++	struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
++	int i;
++
++	for (i = 0; i < NUM_PWM; i++)
++		pwm_disable(&pc->chip.pwms[i]);
++
++	return pwmchip_remove(&pc->chip);
++}
++
++static const struct of_device_id mtk_pwm_of_match[] = {
++	{ .compatible = "mediatek,mt7628-pwm" },
++	{ }
++};
++
++MODULE_DEVICE_TABLE(of, mtk_pwm_of_match);
++
++static struct platform_driver mtk_pwm_driver = {
++	.driver = {
++		.name = "mtk-pwm",
++		.owner = THIS_MODULE,
++		.of_match_table = mtk_pwm_of_match,
++	},
++	.probe = mtk_pwm_probe,
++	.remove = mtk_pwm_remove,
++};
++
++module_platform_driver(mtk_pwm_driver);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
++MODULE_ALIAS("platform:mtk-pwm");