i2c: mt65xx: add 4GB DMA mode support in i2c driver

If 4GB mode is enabled, we should add 4GB DMA mode support in i2c
driver. Set 4GB mode register to support 4GB mode.

Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
[wsa: updated commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-mt65xx.c

@@ -60,6 +60,7 @@
 #define I2C_DMA_INT_FLAG_NONE		0x0000
 #define I2C_DMA_CLR_FLAG		0x0000
 #define I2C_DMA_HARD_RST		0x0002
+#define I2C_DMA_4G_MODE			0x0001
 
 #define I2C_DEFAULT_SPEED		100000	/* hz */
 #define MAX_FS_MODE_SPEED		400000
@@ -88,6 +89,8 @@ enum DMA_REGS_OFFSET {
 	OFFSET_RX_MEM_ADDR = 0x20,
 	OFFSET_TX_LEN = 0x24,
 	OFFSET_RX_LEN = 0x28,
+	OFFSET_TX_4G_MODE = 0x54,
+	OFFSET_RX_4G_MODE = 0x58,
 };
 
 enum i2c_trans_st_rs {
@@ -133,6 +136,7 @@ struct mtk_i2c_compatible {
 	unsigned char dcm: 1;
 	unsigned char auto_restart: 1;
 	unsigned char aux_len_reg: 1;
+	unsigned char support_33bits: 1;
 };
 
 struct mtk_i2c {
@@ -182,6 +186,7 @@ static const struct mtk_i2c_compatible mt6577_compat = {
 	.dcm = 1,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
+	.support_33bits = 0,
 };
 
 static const struct mtk_i2c_compatible mt6589_compat = {
@@ -190,6 +195,7 @@ static const struct mtk_i2c_compatible mt6589_compat = {
 	.dcm = 0,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
+	.support_33bits = 0,
 };
 
 static const struct mtk_i2c_compatible mt8173_compat = {
@@ -198,6 +204,7 @@ static const struct mtk_i2c_compatible mt8173_compat = {
 	.dcm = 1,
 	.auto_restart = 1,
 	.aux_len_reg = 1,
+	.support_33bits = 1,
 };
 
 static const struct of_device_id mtk_i2c_of_match[] = {
@@ -366,6 +373,11 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk,
 	return 0;
 }
 
+static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
+{
+	return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
+}
+
 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 			       int num, int left_num)
 {
@@ -373,6 +385,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 	u16 start_reg;
 	u16 control_reg;
 	u16 restart_flag = 0;
+	u32 reg_4g_mode;
 	dma_addr_t rpaddr = 0;
 	dma_addr_t wpaddr = 0;
 	int ret;
@@ -439,6 +452,12 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 					msgs->len, DMA_FROM_DEVICE);
 		if (dma_mapping_error(i2c->dev, rpaddr))
 			return -ENOMEM;
+
+		if (i2c->dev_comp->support_33bits) {
+			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
+			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
+		}
+
 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 		writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
 	} else if (i2c->op == I2C_MASTER_WR) {
@@ -448,6 +467,12 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 					msgs->len, DMA_TO_DEVICE);
 		if (dma_mapping_error(i2c->dev, wpaddr))
 			return -ENOMEM;
+
+		if (i2c->dev_comp->support_33bits) {
+			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
+			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
+		}
+
 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
 	} else {
@@ -465,6 +490,15 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 					 msgs->len, DMA_TO_DEVICE);
 			return -ENOMEM;
 		}
+
+		if (i2c->dev_comp->support_33bits) {
+			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
+			writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
+
+			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
+			writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
+		}
+
 		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
 		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
 		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
@@ -729,6 +763,14 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	if (i2c->dev_comp->support_33bits) {
+		ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33));
+		if (ret) {
+			dev_err(&pdev->dev, "dma_set_mask return error.\n");
+			return ret;
+		}
+	}
+
 	ret = mtk_i2c_clock_enable(i2c);
 	if (ret) {
 		dev_err(&pdev->dev, "clock enable failed!\n");