drm/panel: s6e63m0: Switch to DBI abstraction for SPI

The SPI access to s6e63m0 is using the DBI protocol, so switch
to using the elaborate DBI protocol implementation in the DRM
DBI helper library.

Acked-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210614181135.1124445-2-linus.walleij@linaro.org

1 files changed, 31 insertions, 52 deletions

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c b/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
index 326deb3177b6..3669cc3719ce 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c
@@ -5,62 +5,38 @@
 #include <linux/spi/spi.h>
 #include <linux/delay.h>
 
+#include <drm/drm_mipi_dbi.h>
 #include <drm/drm_print.h>
 
 #include "panel-samsung-s6e63m0.h"
 
-#define DATA_MASK	0x100
+static const u8 s6e63m0_dbi_read_commands[] = {
+	MCS_READ_ID1,
+	MCS_READ_ID2,
+	MCS_READ_ID3,
+	0, /* sentinel */
+};
 
-static int s6e63m0_spi_dcs_read(struct device *dev, const u8 cmd, u8 *data)
+static int s6e63m0_spi_dcs_read(struct device *dev, void *trsp,
+				const u8 cmd, u8 *data)
 {
-	struct spi_device *spi = to_spi_device(dev);
-	u16 buf[1];
-	u16 rbuf[1];
+	struct mipi_dbi *dbi = trsp;
 	int ret;
 
-	/* SPI buffers are always in CPU order */
-	buf[0] = (u16)cmd;
-	ret = spi_write_then_read(spi, buf, 2, rbuf, 2);
-	dev_dbg(dev, "READ CMD: %04x RET: %04x\n", buf[0], rbuf[0]);
-	if (!ret)
-		/* These high 8 bits of the 9 contains the readout */
-		*data = (rbuf[0] & 0x1ff) >> 1;
+	ret = mipi_dbi_command_read(dbi, cmd, data);
+	if (ret)
+		dev_err(dev, "error on DBI read command %02x\n", cmd);
 
 	return ret;
 }
 
-static int s6e63m0_spi_write_word(struct device *dev, u16 data)
-{
-	struct spi_device *spi = to_spi_device(dev);
-
-	/* SPI buffers are always in CPU order */
-	return spi_write(spi, &data, 2);
-}
-
-static int s6e63m0_spi_dcs_write(struct device *dev, const u8 *data, size_t len)
+static int s6e63m0_spi_dcs_write(struct device *dev, void *trsp,
+				 const u8 *data, size_t len)
 {
-	int ret = 0;
-
-	dev_dbg(dev, "SPI writing dcs seq: %*ph\n", (int)len, data);
-
-	/*
-	 * This sends 9 bits with the first bit (bit 8) set to 0
-	 * This indicates that this is a command. Anything after the
-	 * command is data.
-	 */
-	ret = s6e63m0_spi_write_word(dev, *data);
-
-	while (!ret && --len) {
-		++data;
-		/* This sends 9 bits with the first bit (bit 8) set to 1 */
-		ret = s6e63m0_spi_write_word(dev, *data | DATA_MASK);
-	}
-
-	if (ret) {
-		dev_err(dev, "SPI error %d writing dcs seq: %*ph\n", ret,
-			(int)len, data);
-	}
+	struct mipi_dbi *dbi = trsp;
+	int ret;
 
+	ret = mipi_dbi_command_stackbuf(dbi, data[0], (data + 1), (len - 1));
 	usleep_range(300, 310);
 
 	return ret;
@@ -69,18 +45,21 @@ static int s6e63m0_spi_dcs_write(struct device *dev, const u8 *data, size_t len)
 static int s6e63m0_spi_probe(struct spi_device *spi)
 {
 	struct device *dev = &spi->dev;
+	struct mipi_dbi *dbi;
 	int ret;
 
-	spi->bits_per_word = 9;
-	/* Preserve e.g. SPI_3WIRE setting */
-	spi->mode |= SPI_MODE_3;
-	ret = spi_setup(spi);
-	if (ret < 0) {
-		dev_err(dev, "spi setup failed.\n");
-		return ret;
-	}
-	return s6e63m0_probe(dev, s6e63m0_spi_dcs_read, s6e63m0_spi_dcs_write,
-			     false);
+	dbi = devm_kzalloc(dev, sizeof(*dbi), GFP_KERNEL);
+	if (!dbi)
+		return -ENOMEM;
+
+	ret = mipi_dbi_spi_init(spi, dbi, NULL);
+	if (ret)
+		return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
+	/* Register our custom MCS read commands */
+	dbi->read_commands = s6e63m0_dbi_read_commands;
+
+	return s6e63m0_probe(dev, dbi, s6e63m0_spi_dcs_read,
+			     s6e63m0_spi_dcs_write, false);
 }
 
 static int s6e63m0_spi_remove(struct spi_device *spi)