Hello Maxim,<br><br><div class="gmail_quote">On Tue, Jul 31, 2012 at 3:59 PM, Maxime Ripard <span dir="ltr"><<a href="mailto:maxime.ripard@free-electrons.com" target="_blank">maxime.ripard@free-electrons.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">This patch adds support for the Solomon SSD1307 OLED<br>
controller found on the Crystalfontz CFA10036 board.<br>
<br>
This controller can drive a display with a resolution up<br>
to 128x39 and can operate over I2C or SPI.<br>
<br>
The current driver has only been tested on the CFA-10036,<br>
that is using this controller over I2C to driver a 96x16<br>
OLED screen.<br>
<br>
Signed-off-by: Maxime Ripard <<a href="mailto:maxime.ripard@free-electrons.com">maxime.ripard@free-electrons.com</a>><br>
Cc: Brian Lilly <<a href="mailto:brian@crystalfontz.com">brian@crystalfontz.com</a>><br>
---<br>
.../devicetree/bindings/video/ssd1307fb.txt | 24 ++<br>
drivers/video/Kconfig | 14 +<br>
drivers/video/Makefile | 1 +<br>
drivers/video/ssd1307fb.c | 418 ++++++++++++++++++++<br>
4 files changed, 457 insertions(+)<br>
create mode 100644 Documentation/devicetree/bindings/video/ssd1307fb.txt<br>
create mode 100644 drivers/video/ssd1307fb.c<br>
<br>
diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt b/Documentation/devicetree/bindings/video/ssd1307fb.txt<br>
new file mode 100644<br>
index 0000000..791e14f<br>
--- /dev/null<br>
+++ b/Documentation/devicetree/bindings/video/ssd1307fb.txt<br>
@@ -0,0 +1,24 @@<br>
+* Solomon SSD1307 Framebuffer Driver<br>
+<br>
+Required properties:<br>
+ - compatible: Should be "solomon,ssd1307fb-<bus>". The only supported bus for<br>
+ now is i2c.<br>
+ - reg: Should contain address of the controller on the I2C bus. Most likely<br>
+ 0x3c or 0x3d<br>
+ - pwm: Should contain the pwm to use according to the OF device tree PWM<br>
+ specification [0]<br>
+ - oled-reset-gpio: Should contain the GPIO used to reset the OLED display<br>
+<br>
+Optional properties:<br>
+ - oled-reset-active-low: Is the reset gpio is active on physical low?<br>
+<br>
+[0]: Documentation/devicetree/bindings/pwm/pwm.txt<br>
+<br>
+Examples:<br>
+ssd1307: oled@3c {<br>
+ compatible = "solomon,ssd1307fb-i2c";<br>
+ reg = <0x3c>;<br>
+ pwms = <&pwm 4 3000>;<br>
+ oled-reset-gpio = <&gpio2 7 1>;<br>
+ oled-reset-active-low;<br>
+};<br>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig<br>
index 0217f74..21ae6dd 100644<br>
--- a/drivers/video/Kconfig<br>
+++ b/drivers/video/Kconfig<br>
@@ -2469,4 +2469,18 @@ config FB_SH_MOBILE_MERAM<br>
Up to 4 memory channels can be configured, allowing 4 RGB or<br>
2 YCbCr framebuffers to be configured.<br>
<br>
+<br>
+config FB_SSD1307<br>
+ tristate "Solomon SSD1307 framebuffer support"<br>
+ depends on FB && I2C<br>
+ select FB_SYS_FOPS<br>
+ select FB_SYS_FILLRECT<br>
+ select FB_SYS_COPYAREA<br>
+ select FB_SYS_IMAGEBLIT<br>
+ select FB_DEFERRED_IO<br>
+ select PWM<br>
+ help<br>
+ This driver implements support for the Solomon SSD1307<br>
+ OLED controller over I2C.<br>
+<br>
endmenu<br>
diff --git a/drivers/video/Makefile b/drivers/video/Makefile<br>
index ee8dafb..6bbb72c 100644<br>
--- a/drivers/video/Makefile<br>
+++ b/drivers/video/Makefile<br>
@@ -164,6 +164,7 @@ obj-$(CONFIG_FB_BFIN_7393) += bfin_adv7393fb.o<br>
obj-$(CONFIG_FB_MX3) += mx3fb.o<br>
obj-$(CONFIG_FB_DA8XX) += da8xx-fb.o<br>
obj-$(CONFIG_FB_MXS) += mxsfb.o<br>
+obj-$(CONFIG_FB_SSD1307) += ssd1307fb.o<br>
<br>
# the test framebuffer is last<br>
obj-$(CONFIG_FB_VIRTUAL) += vfb.o<br>
diff --git a/drivers/video/ssd1307fb.c b/drivers/video/ssd1307fb.c<br>
new file mode 100644<br>
index 0000000..c705ab4<br>
--- /dev/null<br>
+++ b/drivers/video/ssd1307fb.c<br>
@@ -0,0 +1,418 @@<br>
+/*<br>
+ * Driver for the Solomon SSD1307 OLED controler<br>
+ *<br>
+ * Copyright 2012 Free Electrons<br>
+ *<br>
+ * Licensed under the GPLv2 or later.<br>
+ */<br>
+<br>
+#include <linux/module.h><br>
+#include <linux/kernel.h><br>
+#include <linux/i2c.h><br>
+#include <linux/fb.h><br>
+#include <linux/uaccess.h><br>
+#include <linux/of_device.h><br>
+#include <linux/of_gpio.h><br>
+#include <linux/pwm.h><br>
+#include <linux/delay.h><br>
+<br>
+#define SSD1307FB_WIDTH 96<br>
+#define SSD1307FB_HEIGHT 16<br>
+<br>
+#define SSD1307FB_DATA 0x40<br>
+#define SSD1307FB_COMMAND 0x80<br>
+<br>
+#define SSD1307FB_CONTRAST 0x81<br>
+#define SSD1307FB_SEG_REMAP_ON 0xa1<br>
+#define SSD1307FB_DISPLAY_OFF 0xae<br>
+#define SSD1307FB_DISPLAY_ON 0xaf<br>
+#define SSD1307FB_START_PAGE_ADDRESS 0xb0<br>
+<br>
+struct ssd1307fb_par {<br>
+ struct i2c_client *client;<br>
+ struct fb_info *info;<br>
+ struct pwm_device *pwm;<br>
+ u32 pwm_period;<br>
+ int reset;<br>
+};<br>
+<br>
+static struct fb_fix_screeninfo ssd1307fb_fix __devinitdata = {<br>
+ .id = "Solomon SSD1307",<br>
+ .type = FB_TYPE_PACKED_PIXELS,<br>
+ .visual = FB_VISUAL_MONO10,<br>
+ .xpanstep = 0,<br>
+ .ypanstep = 0,<br>
+ .ywrapstep = 0,<br>
+ .line_length = SSD1307FB_WIDTH / 8,<br>
+ .accel = FB_ACCEL_NONE,<br>
+};<br>
+<br>
+static struct fb_var_screeninfo ssd1307fb_var __devinitdata = {<br>
+ .xres = SSD1307FB_WIDTH,<br>
+ .yres = SSD1307FB_HEIGHT,<br>
+ .xres_virtual = SSD1307FB_WIDTH,<br>
+ .yres_virtual = SSD1307FB_HEIGHT,<br>
+ .bits_per_pixel = 1,<br>
+};<br>
+<br>
+static int ssd1307fb_write_array(struct i2c_client *client, u8 type, u8* cmd, u32 len)<br>
+{<br>
+ u8 *buf;<br>
+ int ret = 0;<br>
+<br>
+ buf = kzalloc(len + 1, GFP_KERNEL);<br>
+ if (!buf) {<br>
+ dev_err(&client->dev, "Couldn't allocate sending buffer.\n");<br>
+ ret = -ENOMEM;<br>
+ goto out;<br></blockquote><div><br></div><div><div>Why cant we just return from here with -ENOMEM directly rather than jumping to a label, which again just returns?</div><div><br></div></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ }<br>
+<br>
+ buf[0] = type;<br>
+ memcpy(buf + 1, cmd, len);<br>
+<br>
+ ret = i2c_master_send(client, buf, len + 1);<br>
+ if (ret != len + 1) {<br>
+ dev_err(&client->dev, "Couldn't send I2C command.\n");<br>
+ goto error;<br>
+ }<br>
+<br>
+error:<br>
+ kfree(buf);<br>
+out:<br>
+ return ret;<br>
+}<br>
+<br>
+static inline int ssd1307fb_write_cmd_array(struct i2c_client *client, u8* cmd, u32 len)<br>
+{<br>
+ return ssd1307fb_write_array(client, SSD1307FB_COMMAND, cmd, len);<br>
+}<br>
+<br>
+static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)<br>
+{<br>
+ return ssd1307fb_write_cmd_array(client, &cmd, 1);<br>
+}<br>
+<br>
+static inline int ssd1307fb_write_data_array(struct i2c_client *client, u8* cmd, u32 len)<br>
+{<br>
+ return ssd1307fb_write_array(client, SSD1307FB_DATA, cmd, len);<br>
+}<br>
+<br>
+static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data)<br>
+{<br>
+ return ssd1307fb_write_data_array(client, &data, 1);<br>
+}<br>
+<br>
+static int ssd1307fb_set(struct i2c_client *client, u8 value)<br>
+{<br>
+ int i, j, ret;<br>
+<br>
+ for (i = 1; i <= (SSD1307FB_HEIGHT / 8); i++) {<br>
+ ret = ssd1307fb_write_cmd(client, SSD1307FB_START_PAGE_ADDRESS + i);<br>
+ if (ret < 0)<br>
+ goto i2c_error;<br>
+<br>
+ ret = ssd1307fb_write_cmd(client, 0x00);<br>
+ if (ret < 0)<br>
+ goto i2c_error;<br>
+<br>
+ ret = ssd1307fb_write_cmd(client, 0x10);<br>
+ if (ret < 0)<br>
+ goto i2c_error;<br>
+<br>
+ for (j = 0; j < SSD1307FB_WIDTH; j++)<br>
+ ssd1307fb_write_data(client, value);<br>
+ }<br>
+<br>
+ return 0;<br>
+<br>
+i2c_error:<br>
+ dev_err(&client->dev, "Couldn't send i2c command: %d\n", ret);<br>
+ return ret;<br>
+}<br>
+<br>
+static void ssd1307fb_update_display(struct ssd1307fb_par *par)<br>
+{<br>
+ u8 *vmem = par->info->screen_base;<br>
+ int i, j, k;<br>
+<br>
+ /*<br>
+ * The screen is divided in pages, each having a height of 8<br>
+ * pixels, and the width of the screen. When sending a byte of<br>
+ * data to the controller, it gives the 8 bits for the current<br>
+ * column. I.e, the first byte are the 8 bits of the first<br>
+ * column, then the 8 bits for the second column, etc.<br>
+ *<br>
+ *<br>
+ * Representation of the screen, assuming it is 5 bits<br>
+ * wide. Each letter-number combination is a bit that controls<br>
+ * one pixel.<br>
+ *<br>
+ * A0 A1 A2 A3 A4<br>
+ * B0 B1 B2 B3 B4<br>
+ * C0 C1 C2 C3 C4<br>
+ * D0 D1 D2 D3 D4<br>
+ * E0 E1 E2 E3 E4<br>
+ * F0 F1 F2 F3 F4<br>
+ * G0 G1 G2 G3 G4<br>
+ * H0 H1 H2 H3 H4<br>
+ *<br>
+ * If you want to update this screen, you need to send 5 bytes:<br>
+ * (1) A0 B0 C0 D0 E0 F0 G0 H0<br>
+ * (2) A1 B1 C1 D1 E1 F1 G1 H1<br>
+ * (3) A2 B2 C2 D2 E2 F2 G2 H2<br>
+ * (4) A3 B3 C3 D3 E3 F3 G3 H3<br>
+ * (5) A4 B4 C4 D4 E4 F4 G4 H4<br>
+ */<br>
+<br>
+ for (i = 0; i < (SSD1307FB_HEIGHT / 8); i++) {<br>
+ ssd1307fb_write_cmd(par->client, SSD1307FB_START_PAGE_ADDRESS + (i + 1));<br>
+ ssd1307fb_write_cmd(par->client, 0x00);<br>
+ ssd1307fb_write_cmd(par->client, 0x10);<br>
+<br>
+ for (j = 0; j < SSD1307FB_WIDTH; j++) {<br>
+ u8 buf = 0;<br>
+ for (k = 0; k < 8; k++) {<br>
+ u32 page_length = SSD1307FB_WIDTH * i;<br>
+ u32 index = page_length + (SSD1307FB_WIDTH * k + j) / 8;<br>
+ u8 byte = *(vmem + index);<br>
+ u8 bit = byte & (1 << (7 - (j % 8)));<br>
+ bit = bit >> (7 - (j % 8));<br>
+ buf |= bit << k;<br>
+ }<br>
+ ssd1307fb_write_data(par->client, buf);<br>
+ }<br>
+ }<br>
+<br>
+ return;<br></blockquote><div><br></div><div>'return' not required?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+}<br>
+<br>
+<br>
+static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,<br>
+ size_t count, loff_t *ppos)<br>
+{<br>
+ struct ssd1307fb_par *par = info->par;<br>
+ unsigned long p = *ppos;<br>
+ void *dst;<br>
+ int err = 0;<br>
+<br>
+ dst = (void __force *) (info->screen_base + p);<br>
+<br>
+ if (copy_from_user(dst, buf, count))<br>
+ err = -EFAULT;<br>
+<br>
+ if (!err)<br>
+ *ppos += count;<br>
+<br>
+ ssd1307fb_update_display(par);<br>
+<br>
+ return (err) ? err : count;<br>
+}<br>
+<br>
+static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)<br>
+{<br>
+ struct ssd1307fb_par *par = info->par;<br>
+ sys_fillrect(info, rect);<br>
+ ssd1307fb_update_display(par);<br>
+}<br>
+<br>
+static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)<br>
+{<br>
+ struct ssd1307fb_par *par = info->par;<br>
+ sys_copyarea(info, area);<br>
+ ssd1307fb_update_display(par);<br>
+}<br>
+<br>
+static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)<br>
+{<br>
+ struct ssd1307fb_par *par = info->par;<br>
+ sys_imageblit(info, image);<br>
+ ssd1307fb_update_display(par);<br>
+}<br>
+<br>
+static struct fb_ops ssd1307fb_ops = {<br>
+ .owner = THIS_MODULE,<br>
+ .fb_read = fb_sys_read,<br>
+ .fb_write = ssd1307fb_write,<br>
+ .fb_fillrect = ssd1307fb_fillrect,<br>
+ .fb_copyarea = ssd1307fb_copyarea,<br>
+ .fb_imageblit = ssd1307fb_imageblit,<br>
+};<br>
+<br>
+static void ssd1307fb_deferred_io(struct fb_info *info,<br>
+ struct list_head *pagelist)<br>
+{<br>
+ ssd1307fb_update_display(info->par);<br>
+}<br>
+<br>
+static struct fb_deferred_io ssd1307fb_defio = {<br>
+ .delay = HZ,<br>
+ .deferred_io = ssd1307fb_deferred_io,<br>
+};<br>
+<br>
+static int __devinit ssd1307fb_probe(struct i2c_client *client, const struct i2c_device_id *id)<br>
+{<br>
+ struct fb_info *info;<br>
+ u32 vmem_size = SSD1307FB_WIDTH * SSD1307FB_HEIGHT / 8;<br>
+ struct ssd1307fb_par *par;<br>
+ u8 *vmem;<br>
+ int ret;<br>
+<br>
+ if (!client->dev.of_node) {<br>
+ dev_err(&client->dev, "No device tree data found!\n");<br>
+ ret = -EINVAL;<br>
+ goto generic_error;<br></blockquote><div><br></div><div>Again, can just return from here with the error value...</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ }<br>
+<br>
+ info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);<br>
+ if (!info) {<br>
+ ret = -ENOMEM;<br>
+ goto generic_error;<br></blockquote><div><br></div><div>ditto</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ }<br>
+<br>
+ vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);<br>
+ if (!vmem) {<br>
+ dev_err(&client->dev, "Couldn't allocate graphical memory.\n");<br>
+ ret = -ENOMEM;<br>
+ goto generic_error;<br></blockquote><div><br></div><div>ditto
</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ }<br>
+<br>
+ info->fbops = &ssd1307fb_ops;<br>
+ info->fix = ssd1307fb_fix;<br>
+ info->fbdefio = &ssd1307fb_defio;<br>
+<br>
+ info->var = ssd1307fb_var;<br>
+ info->var.red.length = 1;<br>
+ info->var.red.offset = 0;<br>
+ info->var.green.length = 1;<br>
+ info->var.green.offset = 0;<br>
+ info->var.blue.length = 1;<br>
+ info->var.blue.offset = 0;<br>
+<br>
+ info->screen_base = (u8 __force __iomem *)vmem;<br>
+ info->fix.smem_start = (unsigned long)vmem;<br>
+ info->fix.smem_len = vmem_size;<br>
+<br>
+ fb_deferred_io_init(info);<br>
+<br>
+ par = info->par;<br>
+ par->info = info;<br>
+ par->client = client;<br>
+<br>
+ par->reset = of_get_named_gpio(client->dev.of_node,<br>
+ "oled-reset-gpio", 0);<br>
+ if (gpio_is_valid(par->reset)) {<br>
+ int flags = GPIOF_OUT_INIT_HIGH;<br>
+ if (of_get_property(client->dev.of_node,<br>
+ "oled-reset-active-low", NULL))<br>
+ flags = GPIOF_OUT_INIT_LOW;<br>
+ ret = devm_gpio_request_one(&client->dev, par->reset,<br>
+ flags, "oled-reset");<br>
+ if (ret) {<br>
+ dev_err(&client->dev,<br>
+ "failed to request gpio %d: %d\n",<br>
+ par->reset, ret);<br>
+ goto reset_oled_error;<br>
+ }<br>
+ }<br>
+<br>
+ par->pwm = pwm_get(&client->dev, NULL);<br>
+ if (IS_ERR(par->pwm)) {<br>
+ dev_err(&client->dev, "Could not get PWM from device tree!\n");<br>
+ ret = PTR_ERR(par->pwm);<br>
+ goto pwm_error;<br>
+ }<br>
+<br>
+ par->pwm_period = pwm_get_period(par->pwm);<br>
+<br>
+ dev_dbg(&client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period);<br>
+<br>
+ ret = register_framebuffer(info);<br>
+ if (ret) {<br>
+ dev_err(&client->dev, "Couldn't register the framebuffer\n");<br>
+ goto fbreg_error;<br>
+ }<br>
+<br>
+ i2c_set_clientdata(client, info);<br>
+<br>
+ /* Reset the screen */<br>
+ gpio_set_value(par->reset, 1);<br>
+ udelay(4);<br>
+ gpio_set_value(par->reset, 0);<br>
+ udelay(4);<br>
+<br>
+ /* Enable the PWM */<br>
+ pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);<br>
+ pwm_enable(par->pwm);<br>
+<br>
+ /* Map column 127 of the OLED to segment 0 */<br>
+ ret = ssd1307fb_write_cmd(client, SSD1307FB_SEG_REMAP_ON);<br>
+ if (ret < 0) {<br>
+ dev_err(&client->dev, "Couldn't remap the screen.\n");<br>
+ goto remap_error;<br>
+ }<br>
+<br>
+ /* Turn on the display */<br>
+ ret = ssd1307fb_write_cmd(client, SSD1307FB_DISPLAY_ON);<br>
+ if (ret < 0) {<br>
+ dev_err(&client->dev, "Couldn't turn the display on.\n");<br>
+ goto remap_error;<br>
+ }<br>
+<br>
+ dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info-><a href="http://fix.id" target="_blank">fix.id</a>, vmem_size);<br>
+<br>
+ return 0;<br>
+<br>
+remap_error:<br>
+ unregister_framebuffer(info);<br>
+ pwm_disable(par->pwm);<br>
+fbreg_error:<br>
+ pwm_put(par->pwm);<br>
+pwm_error:<br>
+reset_oled_error:<br>
+ fb_deferred_io_cleanup(info);<br>
+ framebuffer_release(info);<br>
+generic_error:<br>
+ return ret;<br>
+}<br>
+<br>
+static int __devexit ssd1307fb_remove(struct i2c_client *client)<br>
+{<br>
+ struct fb_info *info = i2c_get_clientdata(client);<br>
+ struct ssd1307fb_par *par = info->par;<br>
+ unregister_framebuffer(info);<br>
+ pwm_disable(par->pwm);<br>
+ pwm_put(par->pwm);<br>
+ fb_deferred_io_cleanup(info);<br>
+ framebuffer_release(info);<br>
+<br>
+ return 0;<br>
+}<br>
+<br>
+static const struct i2c_device_id ssd1307fb_i2c_id[] = {<br>
+ { "ssd1307fb", 0 },<br>
+ { }<br>
+};<br>
+MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);<br>
+<br>
+static const struct of_device_id ssd1307fb_of_match[] = {<br>
+ { .compatible = "solomon,ssd1307fb-i2c" },<br>
+ {},<br>
+};<br>
+MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);<br>
+<br>
+static struct i2c_driver ssd1307fb_driver = {<br>
+ .probe = ssd1307fb_probe,<br>
+ .remove = __devexit_p(ssd1307fb_remove),<br>
+ .id_table = ssd1307fb_i2c_id,<br>
+ .driver = {<br>
+ .name = "ssd1307fb",<br>
+ .of_match_table = of_match_ptr(ssd1307fb_of_match),<br>
+ .owner = THIS_MODULE,<br>
+ },<br>
+};<br>
+<br>
+module_i2c_driver(ssd1307fb_driver);<br>
+<br>
+MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controler");<br>
+MODULE_AUTHOR("Maxime Ripard <<a href="mailto:maxime.ripard@free-electrons.com">maxime.ripard@free-electrons.com</a>>");<br>
+MODULE_LICENSE("GPL");<br>
<span class="HOEnZb"><font color="#888888">--<br>
1.7.9.5<br>
<br>
<br>
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<a href="mailto:linux-arm-kernel@lists.infradead.org">linux-arm-kernel@lists.infradead.org</a><br>
<a href="http://lists.infradead.org/mailman/listinfo/linux-arm-kernel" target="_blank">http://lists.infradead.org/mailman/listinfo/linux-arm-kernel</a></font></span></blockquote><div><br></div><div>Regards,</div><div>-Amar </div>
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