mfd: rsmu: Support 32-bit address space

We used to assume 0x2010xxxx address. Now that we need to access
0x2011xxxx address, we need to support read/write the whole 32-bit
address space.

Also defined RSMU_MAX_WRITE_COUNT and RSMU_MAX_READ_COUNT for readability

Signed-off-by: Min Li <min.li.xe@renesas.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/MW5PR03MB693295AF31ABCAF6AE52EE74A08B9@MW5PR03MB6932.namprd03.prod.outlook.com

1 files changed, 33 insertions, 19 deletions

diff --git a/drivers/mfd/rsmu_spi.c b/drivers/mfd/rsmu_spi.c
index 2428aaa9aaed..a4a595bb8d0d 100644
--- a/drivers/mfd/rsmu_spi.c
+++ b/drivers/mfd/rsmu_spi.c
@@ -19,19 +19,21 @@
 
 #define	RSMU_CM_PAGE_ADDR		0x7C
 #define	RSMU_SABRE_PAGE_ADDR		0x7F
-#define	RSMU_HIGHER_ADDR_MASK		0xFF80
-#define	RSMU_HIGHER_ADDR_SHIFT		7
-#define	RSMU_LOWER_ADDR_MASK		0x7F
+#define	RSMU_PAGE_MASK			0xFFFFFF80
+#define	RSMU_ADDR_MASK			0x7F
 
 static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
 {
 	struct spi_device *client = to_spi_device(rsmu->dev);
 	struct spi_transfer xfer = {0};
 	struct spi_message msg;
-	u8 cmd[256] = {0};
-	u8 rsp[256] = {0};
+	u8 cmd[RSMU_MAX_READ_COUNT + 1] = {0};
+	u8 rsp[RSMU_MAX_READ_COUNT + 1] = {0};
 	int ret;
 
+	if (bytes > RSMU_MAX_READ_COUNT)
+		return -EINVAL;
+
 	cmd[0] = reg | 0x80;
 	xfer.rx_buf = rsp;
 	xfer.len = bytes + 1;
@@ -66,7 +68,10 @@ static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes
 	struct spi_device *client = to_spi_device(rsmu->dev);
 	struct spi_transfer xfer = {0};
 	struct spi_message msg;
-	u8 cmd[256] = {0};
+	u8 cmd[RSMU_MAX_WRITE_COUNT + 1] = {0};
+
+	if (bytes > RSMU_MAX_WRITE_COUNT)
+		return -EINVAL;
 
 	cmd[0] = reg;
 	memcpy(&cmd[1], buf, bytes);
@@ -86,26 +91,35 @@ static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes
  * 16-bit register address: the lower 7 bits of the register address come
  * from the offset addr byte and the upper 9 bits come from the page register.
  */
-static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u16 reg)
+static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg)
 {
 	u8 page_reg;
-	u8 buf[2];
+	u8 buf[4];
 	u16 bytes;
-	u16 page;
+	u32 page;
 	int err;
 
 	switch (rsmu->type) {
 	case RSMU_CM:
+		/* Do not modify page register for none-scsr registers */
+		if (reg < RSMU_CM_SCSR_BASE)
+			return 0;
 		page_reg = RSMU_CM_PAGE_ADDR;
-		page = reg & RSMU_HIGHER_ADDR_MASK;
+		page = reg & RSMU_PAGE_MASK;
 		buf[0] = (u8)(page & 0xff);
 		buf[1] = (u8)((page >> 8) & 0xff);
-		bytes = 2;
+		buf[2] = (u8)((page >> 16) & 0xff);
+		buf[3] = (u8)((page >> 24) & 0xff);
+		bytes = 4;
 		break;
 	case RSMU_SABRE:
+		/* Do not modify page register if reg is page register itself */
+		if ((reg & RSMU_ADDR_MASK) == RSMU_ADDR_MASK)
+			return 0;
 		page_reg = RSMU_SABRE_PAGE_ADDR;
-		page = reg >> RSMU_HIGHER_ADDR_SHIFT;
-		buf[0] = (u8)(page & 0xff);
+		page = reg & RSMU_PAGE_MASK;
+		/* The three page bits are located in the single Page Register */
+		buf[0] = (u8)((page >> 7) & 0x7);
 		bytes = 1;
 		break;
 	default:
@@ -129,8 +143,8 @@ static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u16 reg)
 
 static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val)
 {
-	struct rsmu_ddata *rsmu = spi_get_drvdata(context);
-	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
+	struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
+	u8 addr = (u8)(reg & RSMU_ADDR_MASK);
 	int err;
 
 	err = rsmu_write_page_register(rsmu, reg);
@@ -146,8 +160,8 @@ static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val)
 
 static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)
 {
-	struct rsmu_ddata *rsmu = spi_get_drvdata(context);
-	u8 addr = (u8)(reg & RSMU_LOWER_ADDR_MASK);
+	struct rsmu_ddata *rsmu = spi_get_drvdata((struct spi_device *)context);
+	u8 addr = (u8)(reg & RSMU_ADDR_MASK);
 	u8 data = (u8)val;
 	int err;
 
@@ -164,9 +178,9 @@ static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)
 }
 
 static const struct regmap_config rsmu_cm_regmap_config = {
-	.reg_bits = 16,
+	.reg_bits = 32,
 	.val_bits = 8,
-	.max_register = 0xD000,
+	.max_register = 0x20120000,
 	.reg_read = rsmu_reg_read,
 	.reg_write = rsmu_reg_write,
 	.cache_type = REGCACHE_NONE,