[PATCH v2 1/2] fbdev: ssd1307fb: add support for Sino Wealth SH1107 controller

[Jakub Turek <jakub.turek@elsta.tech>]

The SH1107 display controller is very similar to SSD1307 but the main
difference is that SH1107 has different memory layout and uses page mode
adressation only.

The SH1107 relies primarily on vertical page addressing mode where the
internal 128x128 GDDRAM is split into 16 vertical pages, rather than
the horizontal/tile addressing modes natively utilized by the
SSD1306/SSD1307.

Signed-off-by: Jakub Turek <jakub.turek@elsta.tech>
---
 drivers/video/fbdev/ssd1307fb.c | 87 +++++++++++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 11 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 644b8d97b381..19dc7671fa7a 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -20,6 +20,8 @@
 #define SSD1307FB_DATA			0x40
 #define SSD1307FB_COMMAND		0x80
 
+#define SSD1307FB_PAGE_COL_START_LOW	0x00
+#define SSD1307FB_PAGE_COL_START_HIGH	0x10
 #define SSD1307FB_SET_ADDRESS_MODE	0x20
 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL	(0x01)
@@ -54,9 +56,11 @@ struct ssd1307fb_deviceinfo {
 	u32 default_dclk_frq;
 	bool need_pwm;
 	bool need_chargepump;
+	bool page_mode_only;
 };
 
 struct ssd1307fb_par {
+	unsigned page_address_mode : 1;
 	unsigned area_color_enable : 1;
 	unsigned com_invdir : 1;
 	unsigned com_lrremap : 1;
@@ -209,6 +213,34 @@ static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start,
 	return 0;
 }
 
+static int ssd1307fb_set_page_pos(struct ssd1307fb_par *par, u8 page_start,
+				  u8 col_start)
+{
+	int ret;
+	u8 page;
+	u8 col_low;
+	u8 col_high;
+
+	page = SSD1307FB_START_PAGE_ADDRESS | (page_start & 0x0f);
+	col_low = SSD1307FB_PAGE_COL_START_LOW | (col_start & 0x0f);
+	col_high = SSD1307FB_PAGE_COL_START_HIGH |
+		((col_start >> 4) & 0x0f);
+
+	ret = ssd1307fb_write_cmd(par->client, page);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, col_low);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, col_high);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
 				 unsigned int y, unsigned int width,
 				 unsigned int height)
@@ -253,13 +285,15 @@ static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
 	 */
 
-	ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);
-	if (ret < 0)
-		goto out_free;
+	if (!par->page_address_mode) {
+		ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);
+		if (ret < 0)
+			goto out_free;
 
-	ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);
-	if (ret < 0)
-		goto out_free;
+		ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);
+		if (ret < 0)
+			goto out_free;
+	}
 
 	for (i = y / 8; i < y / 8 + pages; i++) {
 		int m = 8;
@@ -274,13 +308,28 @@ static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
 				u8 byte = vmem[(8 * i + k) * line_length +
 					       j / 8];
 				u8 bit = (byte >> (j % 8)) & 1;
+
 				data |= bit << k;
 			}
 			array->data[array_idx++] = data;
 		}
+
+		if (par->page_address_mode) {
+			ret = ssd1307fb_set_page_pos(par, par->page_offset + i,
+						     par->col_offset + x);
+			if (ret < 0)
+				goto out_free;
+
+			ret = ssd1307fb_write_array(par->client, array, width);
+			if (ret < 0)
+				goto out_free;
+
+			array_idx = 0;
+		}
 	}
 
-	ret = ssd1307fb_write_array(par->client, array, width * pages);
+	if (!par->page_address_mode)
+		ret = ssd1307fb_write_array(par->client, array, width * pages);
 
 out_free:
 	kfree(array);
@@ -483,13 +532,17 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 		}
 	}
 
-	/* Switch to horizontal addressing mode */
+	/* Switch to addressing mode */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
 	if (ret < 0)
 		return ret;
 
-	ret = ssd1307fb_write_cmd(par->client,
-				  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
+	if (par->page_address_mode)
+		ret = ssd1307fb_write_cmd(par->client,
+					  SSD1307FB_SET_ADDRESS_MODE_PAGE);
+	else
+		ret = ssd1307fb_write_cmd(par->client,
+					  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
 	if (ret < 0)
 		return ret;
 
@@ -562,6 +615,13 @@ static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {
 	.default_dclk_frq = 10,
 };
 
+static struct ssd1307fb_deviceinfo ssd1307fb_sh1107_deviceinfo = {
+	.default_vcomh = 0x35,
+	.default_dclk_div = 1,
+	.default_dclk_frq = 8,
+	.page_mode_only = 1,
+};
+
 static const struct of_device_id ssd1307fb_of_match[] = {
 	{
 		.compatible = "solomon,ssd1305fb-i2c",
@@ -579,6 +639,10 @@ static const struct of_device_id ssd1307fb_of_match[] = {
 		.compatible = "solomon,ssd1309fb-i2c",
 		.data = (void *)&ssd1307fb_ssd1309_deviceinfo,
 	},
+	{
+		.compatible = "sinowealth,sh1107",
+		.data = (void *)&ssd1307fb_sh1107_deviceinfo,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
@@ -658,6 +722,7 @@ static int ssd1307fb_probe(struct i2c_client *client)
 
 	par->contrast = 127;
 	par->vcomh = par->device_info->default_vcomh;
+	par->page_address_mode = par->device_info->page_mode_only;
 
 	/* Setup display timing */
 	if (device_property_read_u32(dev, "solomon,dclk-div", &par->dclk_div))
@@ -678,7 +743,6 @@ static int ssd1307fb_probe(struct i2c_client *client)
 	ssd1307fb_defio = devm_kzalloc(dev, sizeof(*ssd1307fb_defio),
 				       GFP_KERNEL);
 	if (!ssd1307fb_defio) {
-		dev_err(dev, "Couldn't allocate deferred io.\n");
 		ret = -ENOMEM;
 		goto fb_defio_error;
 	}
@@ -788,6 +852,7 @@ static const struct i2c_device_id ssd1307fb_i2c_id[] = {
 	{ .name = "ssd1306fb" },
 	{ .name = "ssd1307fb" },
 	{ .name = "ssd1309fb" },
+	{ .name = "sh1107fb" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);

-- 
2.34.1