Input: ad7879 - convert to use regmap

Instead of rolling our own infrastructure to provide uniform access to I2C
and SPI buses, let's switch to using regmap.

Reviewed-by: Michael Hennerich <michael.hennerich@analog.com>
Tested-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 17 insertions, 93 deletions

diff --git a/drivers/input/touchscreen/ad7879-spi.c b/drivers/input/touchscreen/ad7879-spi.c
index d42b6b9af191..8fb8ccdfac6a 100644
--- a/drivers/input/touchscreen/ad7879-spi.c
+++ b/drivers/input/touchscreen/ad7879-spi.c
@@ -11,109 +11,29 @@
 #include <linux/spi/spi.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/regmap.h>
 
 #include "ad7879.h"
 
 #define AD7879_DEVID		0x7A	/* AD7879/AD7889 */
 
 #define MAX_SPI_FREQ_HZ      5000000
-#define AD7879_CMD_MAGIC     0xE000
-#define AD7879_CMD_READ      (1 << 10)
-#define AD7879_CMD(reg)      (AD7879_CMD_MAGIC | ((reg) & 0xF))
-#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
-#define AD7879_READCMD(reg)  (AD7879_CMD(reg) | AD7879_CMD_READ)
 
-/*
- * ad7879_read/write are only used for initial setup and for sysfs controls.
- * The main traffic is done in ad7879_collect().
- */
-
-static int ad7879_spi_xfer(struct spi_device *spi,
-			   u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
-{
-	struct spi_message msg;
-	struct spi_transfer *xfers;
-	void *spi_data;
-	u16 *command;
-	u16 *_rx_buf = _rx_buf; /* shut gcc up */
-	u8 idx;
-	int ret;
-
-	xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
-	if (!spi_data)
-		return -ENOMEM;
-
-	spi_message_init(&msg);
-
-	command = spi_data;
-	command[0] = cmd;
-	if (count == 1) {
-		/* ad7879_spi_{read,write} gave us buf on stack */
-		command[1] = *tx_buf;
-		tx_buf = &command[1];
-		_rx_buf = rx_buf;
-		rx_buf = &command[2];
-	}
-
-	++xfers;
-	xfers[0].tx_buf = command;
-	xfers[0].len = 2;
-	spi_message_add_tail(&xfers[0], &msg);
-	++xfers;
-
-	for (idx = 0; idx < count; ++idx) {
-		if (rx_buf)
-			xfers[idx].rx_buf = &rx_buf[idx];
-		if (tx_buf)
-			xfers[idx].tx_buf = &tx_buf[idx];
-		xfers[idx].len = 2;
-		spi_message_add_tail(&xfers[idx], &msg);
-	}
+#define AD7879_CMD_MAGIC     0xE0
+#define AD7879_CMD_READ      BIT(2)
 
-	ret = spi_sync(spi, &msg);
-
-	if (count == 1)
-		_rx_buf[0] = command[2];
-
-	kfree(spi_data);
-
-	return ret;
-}
-
-static int ad7879_spi_multi_read(struct device *dev,
-				 u8 first_reg, u8 count, u16 *buf)
-{
-	struct spi_device *spi = to_spi_device(dev);
-
-	return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
-}
-
-static int ad7879_spi_read(struct device *dev, u8 reg)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	u16 ret, dummy;
-
-	return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
-}
-
-static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	u16 dummy;
-
-	return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
-}
-
-static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
-	.bustype	= BUS_SPI,
-	.read		= ad7879_spi_read,
-	.multi_read	= ad7879_spi_multi_read,
-	.write		= ad7879_spi_write,
+static const struct regmap_config ad7879_spi_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 16,
+	.max_register = 15,
+	.read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
+	.write_flag_mask = AD7879_CMD_MAGIC,
 };
 
 static int ad7879_spi_probe(struct spi_device *spi)
 {
 	struct ad7879 *ts;
+	struct regmap *regmap;
 	int err;
 
 	/* don't exceed max specified SPI CLK frequency */
@@ -125,11 +45,15 @@ static int ad7879_spi_probe(struct spi_device *spi)
 	spi->bits_per_word = 16;
 	err = spi_setup(spi);
 	if (err) {
-	        dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
-	        return err;
+		dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
+		return err;
 	}
 
-	ts = ad7879_probe(&spi->dev, AD7879_DEVID, spi->irq, &ad7879_spi_bus_ops);
+	regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ts = ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
 	if (IS_ERR(ts))
 		return PTR_ERR(ts);