[RFT][PATCH 6/7] net: dsa: microchip: Initial SPI regmap support

[Marek Vasut <marex@denx.de>]

Add basic SPI regmap support into the driver.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Tristram Ha <Tristram.Ha@microchip.com>
Cc: Woojung Huh <Woojung.Huh@microchip.com>
---
 drivers/net/dsa/microchip/Kconfig       |  1 +
 drivers/net/dsa/microchip/ksz9477_spi.c | 85 ++++++++-----------------
 drivers/net/dsa/microchip/ksz_priv.h    |  1 +
 3 files changed, 30 insertions(+), 57 deletions(-)

diff --git a/drivers/net/dsa/microchip/Kconfig b/drivers/net/dsa/microchip/Kconfig
index bea29fde9f3d..3a00cb1b372a 100644
--- a/drivers/net/dsa/microchip/Kconfig
+++ b/drivers/net/dsa/microchip/Kconfig
@@ -1,4 +1,5 @@
 config NET_DSA_MICROCHIP_KSZ_COMMON
+	select REGMAP_SPI
 	tristate
 
 menuconfig NET_DSA_MICROCHIP_KSZ9477
diff --git a/drivers/net/dsa/microchip/ksz9477_spi.c b/drivers/net/dsa/microchip/ksz9477_spi.c
index 4fc36dc2195a..3cf3c8143e98 100644
--- a/drivers/net/dsa/microchip/ksz9477_spi.c
+++ b/drivers/net/dsa/microchip/ksz9477_spi.c
@@ -10,6 +10,7 @@
 #include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/spi/spi.h>
 
 #include "ksz_priv.h"
@@ -22,66 +23,29 @@
 #define SPI_ADDR_MASK			(BIT(SPI_ADDR_SHIFT) - 1)
 #define SPI_TURNAROUND_SHIFT		5
 
-/* Enough to read all switch port registers. */
-#define SPI_TX_BUF_LEN			0x100
-
-static u32 ksz9477_spi_cmd(u32 reg, bool read)
-{
-	u32 txbuf;
-
-	txbuf = reg & SPI_ADDR_MASK;
-	txbuf |= (read ? KS_SPIOP_RD : KS_SPIOP_WR) << SPI_ADDR_SHIFT;
-	txbuf <<= SPI_TURNAROUND_SHIFT;
-	txbuf = cpu_to_be32(txbuf);
-
-	return txbuf;
-}
-
-static int ksz9477_spi_read_reg(struct spi_device *spi, u32 reg, u8 *val,
-				unsigned int len)
-{
-	u32 txbuf = ksz9477_spi_cmd(reg, true);
-
-	return spi_write_then_read(spi, &txbuf, 4, val, len);
-}
-
-static int ksz9477_spi_write_reg(struct spi_device *spi, u32 reg, u8 *val,
-				 unsigned int len)
-{
-	u32 *txbuf = (u32 *)val;
-
-	*txbuf = ksz9477_spi_cmd(reg, false);
-
-	return spi_write(spi, txbuf, 4 + len);
-}
-
-static int ksz_spi_read(struct ksz_device *dev, u32 reg, u8 *data,
-			unsigned int len)
-{
-	struct spi_device *spi = dev->priv;
-
-	return ksz9477_spi_read_reg(spi, reg, data, len);
-}
-
-static int ksz_spi_write(struct ksz_device *dev, u32 reg, void *data,
-			 unsigned int len)
-{
-	struct spi_device *spi = dev->priv;
-	u8 txbuf[8];
-
-	memcpy(txbuf + 4, data, len);
-
-	return ksz9477_spi_write_reg(spi, reg, txbuf, len);
-}
+static const struct regmap_config ksz9477_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 8,
+	.max_register = 0x100,
+	.cache_type = REGCACHE_RBTREE,
+	.read_flag_mask = KS_SPIOP_RD << SPI_ADDR_SHIFT,
+	.write_flag_mask = KS_SPIOP_WR << SPI_ADDR_SHIFT,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+};
 
 static int ksz_spi_read8(struct ksz_device *dev, u32 reg, u8 *val)
 {
-	return ksz_spi_read(dev, reg, val, 1);
+	unsigned int value;
+	int ret = regmap_read(dev->regmap, reg, &value);
+
+	*val = value;
+	return ret;
 }
 
 static int ksz_spi_read16(struct ksz_device *dev, u32 reg, u16 *val)
 {
-	int ret = ksz_spi_read(dev, reg, (u8 *)val, 2);
+	int ret = regmap_bulk_read(dev->regmap, reg, val, 2);
 
 	if (!ret)
 		*val = be16_to_cpu(*val);
@@ -91,7 +55,7 @@ static int ksz_spi_read16(struct ksz_device *dev, u32 reg, u16 *val)
 
 static int ksz_spi_read32(struct ksz_device *dev, u32 reg, u32 *val)
 {
-	int ret = ksz_spi_read(dev, reg, (u8 *)val, 4);
+	int ret = regmap_bulk_read(dev->regmap, reg, val, 4);
 
 	if (!ret)
 		*val = be32_to_cpu(*val);
@@ -101,19 +65,19 @@ static int ksz_spi_read32(struct ksz_device *dev, u32 reg, u32 *val)
 
 static int ksz_spi_write8(struct ksz_device *dev, u32 reg, u8 value)
 {
-	return ksz_spi_write(dev, reg, &value, 1);
+	return regmap_write(dev->regmap, reg, value);
 }
 
 static int ksz_spi_write16(struct ksz_device *dev, u32 reg, u16 value)
 {
 	value = cpu_to_be16(value);
-	return ksz_spi_write(dev, reg, &value, 2);
+	return regmap_bulk_write(dev->regmap, reg, &value, 2);
 }
 
 static int ksz_spi_write32(struct ksz_device *dev, u32 reg, u32 value)
 {
 	value = cpu_to_be32(value);
-	return ksz_spi_write(dev, reg, &value, 4);
+	return regmap_bulk_write(dev->regmap, reg, &value, 4);
 }
 
 static const struct ksz_io_ops ksz9477_spi_ops = {
@@ -134,6 +98,13 @@ static int ksz9477_spi_probe(struct spi_device *spi)
 	if (!dev)
 		return -ENOMEM;
 
+	dev->regmap = devm_regmap_init_spi(spi, &ksz9477_regmap_config);
+	if (IS_ERR(dev->regmap)) {
+		ret = PTR_ERR(dev->regmap);
+		dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
+		return ret;
+	}
+
 	if (spi->dev.platform_data)
 		dev->pdata = spi->dev.platform_data;
 
diff --git a/drivers/net/dsa/microchip/ksz_priv.h b/drivers/net/dsa/microchip/ksz_priv.h
index 3ab14ee0e36b..f9429e1fc7fe 100644
--- a/drivers/net/dsa/microchip/ksz_priv.h
+++ b/drivers/net/dsa/microchip/ksz_priv.h
@@ -56,6 +56,7 @@ struct ksz_device {
 	const struct ksz_dev_ops *dev_ops;
 
 	struct device *dev;
+	struct regmap *regmap;
 
 	void *priv;
 
-- 
2.19.2