[U-Boot] [PATCH 4/9 v3] A driver for the S6E63D6 SPI display controller from Samsung

[Guennadi Liakhovetski]

This is a driver for the S6E63D6 SPI OLED display controller from Samsung.
It only provides access to controller's registers so the client can freely
configure it.

Signed-off-by: Guennadi Liakhovetski <lg at denx.de>
---

Changes since v1: parameters added in function declarations, alphabetical 
order in Makefile, id made configurable by the user, renamed 
configuration parameter to CONFIG_S6E63D6.
Changes since v2: added a comment, explaining the start byte format, empty 
line added before the final return in a function.

 drivers/video/Makefile  |    1 +
 drivers/video/s6e63d6.c |   76 +++++++++++++++++++++++++++++++++++++++++++++++
 include/s6e63d6.h       |   37 +++++++++++++++++++++++
 3 files changed, 114 insertions(+), 0 deletions(-)
 create mode 100644 drivers/video/s6e63d6.c
 create mode 100644 include/s6e63d6.h

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 7fba29f..84d4cb7 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -28,6 +28,7 @@ LIB	:= $(obj)libvideo.a
 COBJS-$(CONFIG_ATI_RADEON_FB) += ati_radeon_fb.o
 COBJS-$(CONFIG_ATMEL_LCD) += atmel_lcdfb.o
 COBJS-$(CONFIG_CFB_CONSOLE) += cfb_console.o
+COBJS-$(CONFIG_S6E63D6) += s6e63d6.o
 COBJS-$(CONFIG_VIDEO_CT69000) += ct69000.o
 COBJS-$(CONFIG_VIDEO_MB862xx) += mb862xx.o
 COBJS-$(CONFIG_VIDEO_SED13806) += sed13806.o
diff --git a/drivers/video/s6e63d6.c b/drivers/video/s6e63d6.c
new file mode 100644
index 0000000..d163506
--- /dev/null
+++ b/drivers/video/s6e63d6.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2009
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg at denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <spi.h>
+#include <s6e63d6.h>
+
+/*
+ * Each transfer is performed as:
+ * 1. chip-select active
+ * 2. send 8-bit start code
+ * 3. send 16-bit data
+ * 4. chip-select inactive
+ */
+static int send_word(struct s6e63d6 *data, u8 rs, u16 word)
+{
+	/*
+	 * The start byte looks like (binary):
+	 * 01110<ID><RS><R/W>
+	 * RS is 0 for index or 1 for data, and R/W is 0 for write.
+	 */
+	u32 buf8 = 0x70 | data->id | (rs & 2);
+	u32 buf16 = cpu_to_le16(word);
+	u32 buf_in;
+	int err;
+
+	err = spi_xfer(data->slave, 8, &buf8, &buf_in, SPI_XFER_BEGIN);
+	if (err)
+		return err;
+
+	return spi_xfer(data->slave, 16, &buf16, &buf_in, SPI_XFER_END);
+}
+
+/* Index and param differ in Register Select bit */
+int s6e63d6_index(struct s6e63d6 *data, u8 idx)
+{
+	return send_word(data, 0, idx);
+}
+
+int s6e63d6_param(struct s6e63d6 *data, u16 param)
+{
+	return send_word(data, 2, param);
+}
+
+int s6e63d6_init(struct s6e63d6 *data)
+{
+	if (data->id != 0 && data->id != 4) {
+		printf("s6e63d6: invalid ID %u\n", data->id);
+		return 1;
+	}
+
+	data->slave = spi_setup_slave(data->bus, data->cs, 100000, SPI_MODE_3);
+	if (!data->slave)
+		return 1;
+
+	return 0;
+}
diff --git a/include/s6e63d6.h b/include/s6e63d6.h
new file mode 100644
index 0000000..9f17fc0
--- /dev/null
+++ b/include/s6e63d6.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2009
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg at denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#ifndef _S6E63D6_H_
+#define _S6E63D6_H_
+
+struct s6e63d6 {
+	unsigned int bus;
+	unsigned int cs;
+	unsigned int id;
+	struct spi_slave *slave;
+};
+
+extern int s6e63d6_init(struct s6e63d6 *data);
+extern int s6e63d6_index(struct s6e63d6 *data, u8 idx);
+extern int s6e63d6_param(struct s6e63d6 *data, u16 param);
+
+#endif
-- 
1.5.4