mediatek: add PWM support for MT7981 SoC

Add patch to support PWM on the MT7981 SoC.
This patch will also be submitted to upstream Linux soon.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 212 insertions, 0 deletions

diff --git a/target/linux/mediatek/patches-5.15/811-pwm-mediatek-Add-support-for-MT7981.patch b/target/linux/mediatek/patches-5.15/811-pwm-mediatek-Add-support-for-MT7981.patch
new file mode 100644
index 0000000000..ab465a7582
--- /dev/null
+++ b/target/linux/mediatek/patches-5.15/811-pwm-mediatek-Add-support-for-MT7981.patch
@@ -0,0 +1,212 @@
+From 947b535ebfe161e1725f1030a09de10d1460371c Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Mon, 23 Jan 2023 20:47:34 +0000
+Subject: [PATCH] pwm: mediatek: Add support for MT7981
+
+The PWM unit on MT7981 uses different register offsets than previous
+MediaTek PWM units. Add support for these new offsets and add support
+for PWM on MT7981 which has 3 PWM channels, one of them is typically
+used for a temperature controlled fan.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/pwm/pwm-mediatek.c | 54 ++++++++++++++++++++++++++++++++------
+ 1 file changed, 46 insertions(+), 8 deletions(-)
+
+--- a/drivers/pwm/pwm-mediatek.c
++++ b/drivers/pwm/pwm-mediatek.c
+@@ -34,10 +34,14 @@
+ 
+ #define PWM_CLK_DIV_MAX		7
+ 
++#define REG_V1			1
++#define REG_V2			2
++
+ struct pwm_mediatek_of_data {
+ 	unsigned int num_pwms;
+ 	bool pwm45_fixup;
+ 	bool has_ck_26m_sel;
++	u8 reg_ver;
+ };
+ 
+ /**
+@@ -59,10 +63,14 @@ struct pwm_mediatek_chip {
+ 	const struct pwm_mediatek_of_data *soc;
+ };
+ 
+-static const unsigned int pwm_mediatek_reg_offset[] = {
++static const unsigned int mtk_pwm_reg_offset_v1[] = {
+ 	0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
+ };
+ 
++static const unsigned int mtk_pwm_reg_offset_v2[] = {
++	0x0080, 0x00c0, 0x0100, 0x0140, 0x0180, 0x1c0, 0x200, 0x0240
++};
++
+ static inline struct pwm_mediatek_chip *
+ to_pwm_mediatek_chip(struct pwm_chip *chip)
+ {
+@@ -111,7 +119,19 @@ static inline void pwm_mediatek_writel(s
+ 				       unsigned int num, unsigned int offset,
+ 				       u32 value)
+ {
+-	writel(value, chip->regs + pwm_mediatek_reg_offset[num] + offset);
++	u32 pwm_offset;
++
++	switch (chip->soc->reg_ver) {
++	case REG_V2:
++		pwm_offset = mtk_pwm_reg_offset_v2[num];
++		break;
++
++	case REG_V1:
++	default:
++		pwm_offset = mtk_pwm_reg_offset_v1[num];
++	}
++
++	writel(value, chip->regs + pwm_offset + offset);
+ }
+ 
+ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
+@@ -146,7 +166,7 @@ static int pwm_mediatek_config(struct pw
+ 
+ 	if (clkdiv > PWM_CLK_DIV_MAX) {
+ 		pwm_mediatek_clk_disable(chip, pwm);
+-		dev_err(chip->dev, "period %d not supported\n", period_ns);
++		dev_err(chip->dev, "period of %d ns not supported\n", period_ns);
+ 		return -EINVAL;
+ 	}
+ 
+@@ -221,24 +241,20 @@ static int pwm_mediatek_probe(struct pla
+ 	if (IS_ERR(pc->regs))
+ 		return PTR_ERR(pc->regs);
+ 
+-	pc->clk_pwms = devm_kcalloc(&pdev->dev, pc->soc->num_pwms,
++	pc->clk_pwms = devm_kmalloc_array(&pdev->dev, pc->soc->num_pwms,
+ 				    sizeof(*pc->clk_pwms), GFP_KERNEL);
+ 	if (!pc->clk_pwms)
+ 		return -ENOMEM;
+ 
+ 	pc->clk_top = devm_clk_get(&pdev->dev, "top");
+-	if (IS_ERR(pc->clk_top)) {
+-		dev_err(&pdev->dev, "clock: top fail: %ld\n",
+-			PTR_ERR(pc->clk_top));
+-		return PTR_ERR(pc->clk_top);
+-	}
++	if (IS_ERR(pc->clk_top))
++		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_top),
++				     "Failed to get top clock\n");
+ 
+ 	pc->clk_main = devm_clk_get(&pdev->dev, "main");
+-	if (IS_ERR(pc->clk_main)) {
+-		dev_err(&pdev->dev, "clock: main fail: %ld\n",
+-			PTR_ERR(pc->clk_main));
+-		return PTR_ERR(pc->clk_main);
+-	}
++	if (IS_ERR(pc->clk_main))
++		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_main),
++				     "Failed to get main clock\n");
+ 
+ 	for (i = 0; i < pc->soc->num_pwms; i++) {
+ 		char name[8];
+@@ -246,11 +262,9 @@ static int pwm_mediatek_probe(struct pla
+ 		snprintf(name, sizeof(name), "pwm%d", i + 1);
+ 
+ 		pc->clk_pwms[i] = devm_clk_get(&pdev->dev, name);
+-		if (IS_ERR(pc->clk_pwms[i])) {
+-			dev_err(&pdev->dev, "clock: %s fail: %ld\n",
+-				name, PTR_ERR(pc->clk_pwms[i]));
+-			return PTR_ERR(pc->clk_pwms[i]);
+-		}
++		if (IS_ERR(pc->clk_pwms[i]))
++			return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk_pwms[i]),
++					     "Failed to get %s clock\n", name);
+ 	}
+ 
+ 	pc->chip.dev = &pdev->dev;
+@@ -258,10 +272,8 @@ static int pwm_mediatek_probe(struct pla
+ 	pc->chip.npwm = pc->soc->num_pwms;
+ 
+ 	ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
+-	if (ret < 0) {
+-		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+-		return ret;
+-	}
++	if (ret < 0)
++		return dev_err_probe(&pdev->dev, ret, "pwmchip_add() failed\n");
+ 
+ 	return 0;
+ }
+@@ -270,48 +282,63 @@ static const struct pwm_mediatek_of_data
+ 	.num_pwms = 8,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = false,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt7622_pwm_data = {
+ 	.num_pwms = 6,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = true,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt7623_pwm_data = {
+ 	.num_pwms = 5,
+ 	.pwm45_fixup = true,
+ 	.has_ck_26m_sel = false,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt7628_pwm_data = {
+ 	.num_pwms = 4,
+ 	.pwm45_fixup = true,
+ 	.has_ck_26m_sel = false,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt7629_pwm_data = {
+ 	.num_pwms = 1,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = false,
++	.reg_ver = REG_V1,
+ };
+ 
+-static const struct pwm_mediatek_of_data mt8183_pwm_data = {
+-	.num_pwms = 4,
++static const struct pwm_mediatek_of_data mt7981_pwm_data = {
++	.num_pwms = 3,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = true,
++	.reg_ver = REG_V2,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt7986_pwm_data = {
+ 	.num_pwms = 2,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = true,
++	.reg_ver = REG_V1,
++};
++
++static const struct pwm_mediatek_of_data mt8183_pwm_data = {
++	.num_pwms = 4,
++	.pwm45_fixup = false,
++	.has_ck_26m_sel = true,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct pwm_mediatek_of_data mt8516_pwm_data = {
+ 	.num_pwms = 5,
+ 	.pwm45_fixup = false,
+ 	.has_ck_26m_sel = true,
++	.reg_ver = REG_V1,
+ };
+ 
+ static const struct of_device_id pwm_mediatek_of_match[] = {
+@@ -320,6 +347,7 @@ static const struct of_device_id pwm_med
+ 	{ .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
+ 	{ .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
+ 	{ .compatible = "mediatek,mt7629-pwm", .data = &mt7629_pwm_data },
++	{ .compatible = "mediatek,mt7981-pwm", .data = &mt7981_pwm_data },
+ 	{ .compatible = "mediatek,mt7986-pwm", .data = &mt7986_pwm_data },
+ 	{ .compatible = "mediatek,mt8183-pwm", .data = &mt8183_pwm_data },
+ 	{ .compatible = "mediatek,mt8516-pwm", .data = &mt8516_pwm_data },