4 files changed, 436 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt b/Documentation/devicetree/bindings/video/ssd1307fb.txt
new file mode 100644
index 000000000000..3d0060cff062
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/ssd1307fb.txt
@@ -0,0 +1,24 @@
+* Solomon SSD1307 Framebuffer Driver
+
+Required properties:
+  - compatible: Should be "solomon,ssd1307fb-<bus>". The only supported bus for
+    now is i2c.
+  - reg: Should contain address of the controller on the I2C bus. Most likely
+         0x3c or 0x3d
+  - pwm: Should contain the pwm to use according to the OF device tree PWM
+         specification [0]
+  - reset-gpios: Should contain the GPIO used to reset the OLED display
+
+Optional properties:
+  - reset-active-low: Is the reset gpio is active on physical low?
+
+[0]: Documentation/devicetree/bindings/pwm/pwm.txt
+
+Examples:
+ssd1307: oled@3c {
+        compatible = "solomon,ssd1307fb-i2c";
+        reg = <0x3c>;
+        pwms = <&pwm 4 3000>;
+        reset-gpios = <&gpio2 7>;
+        reset-active-low;
+};
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 9018a90b4588..9c31277b3a81 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2442,4 +2442,19 @@ config FB_SH_MOBILE_MERAM
           Up to 4 memory channels can be configured, allowing 4 RGB or
           2 YCbCr framebuffers to be configured.
 
+config FB_SSD1307
+        tristate "Solomon SSD1307 framebuffer support"
+        depends on FB && I2C
+        depends on OF
+        depends on GENERIC_GPIO
+        select FB_SYS_FOPS
+        select FB_SYS_FILLRECT
+        select FB_SYS_COPYAREA
+        select FB_SYS_IMAGEBLIT
+        select FB_DEFERRED_IO
+        select PWM
+        help
+          This driver implements support for the Solomon SSD1307
+          OLED controller over I2C.
+
 endmenu
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 23e948ebfab8..768a137a1bac 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -161,6 +161,7 @@ obj-$(CONFIG_FB_BFIN_7393)        += bfin_adv7393fb.o
 obj-$(CONFIG_FB_MX3)              += mx3fb.o
 obj-$(CONFIG_FB_DA8XX)            += da8xx-fb.o
 obj-$(CONFIG_FB_MXS)              += mxsfb.o
+obj-$(CONFIG_FB_SSD1307)          += ssd1307fb.o
 
 # the test framebuffer is last
 obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
diff --git a/drivers/video/ssd1307fb.c b/drivers/video/ssd1307fb.c
new file mode 100644
index 000000000000..6101f5c2f62f
--- /dev/null
+++ b/drivers/video/ssd1307fb.c
@@ -0,0 +1,396 @@
+/*
+ * Driver for the Solomon SSD1307 OLED controler
+ *
+ * Copyright 2012 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/fb.h>
+#include <linux/uaccess.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pwm.h>
+#include <linux/delay.h>
+
+#define SSD1307FB_WIDTH                 96
+#define SSD1307FB_HEIGHT                16
+
+#define SSD1307FB_DATA                  0x40
+#define SSD1307FB_COMMAND               0x80
+
+#define SSD1307FB_CONTRAST              0x81
+#define SSD1307FB_SEG_REMAP_ON          0xa1
+#define SSD1307FB_DISPLAY_OFF           0xae
+#define SSD1307FB_DISPLAY_ON            0xaf
+#define SSD1307FB_START_PAGE_ADDRESS    0xb0
+
+struct ssd1307fb_par {
+        struct i2c_client *client;
+        struct fb_info *info;
+        struct pwm_device *pwm;
+        u32 pwm_period;
+        int reset;
+};
+
+static struct fb_fix_screeninfo ssd1307fb_fix __devinitdata = {
+        .id             = "Solomon SSD1307",
+        .type           = FB_TYPE_PACKED_PIXELS,
+        .visual         = FB_VISUAL_MONO10,
+        .xpanstep       = 0,
+        .ypanstep       = 0,
+        .ywrapstep      = 0,
+        .line_length    = SSD1307FB_WIDTH / 8,
+        .accel          = FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo ssd1307fb_var __devinitdata = {
+        .xres           = SSD1307FB_WIDTH,
+        .yres           = SSD1307FB_HEIGHT,
+        .xres_virtual   = SSD1307FB_WIDTH,
+        .yres_virtual   = SSD1307FB_HEIGHT,
+        .bits_per_pixel = 1,
+};
+
+static int ssd1307fb_write_array(struct i2c_client *client, u8 type, u8 *cmd, u32 len)
+{
+        u8 *buf;
+        int ret = 0;
+
+        buf = kzalloc(len + 1, GFP_KERNEL);
+        if (!buf) {
+                dev_err(&client->dev, "Couldn't allocate sending buffer.\n");
+                return -ENOMEM;
+        }
+
+        buf[0] = type;
+        memcpy(buf + 1, cmd, len);
+
+        ret = i2c_master_send(client, buf, len + 1);
+        if (ret != len + 1) {
+                dev_err(&client->dev, "Couldn't send I2C command.\n");
+                goto error;
+        }
+
+error:
+        kfree(buf);
+        return ret;
+}
+
+static inline int ssd1307fb_write_cmd_array(struct i2c_client *client, u8 *cmd, u32 len)
+{
+        return ssd1307fb_write_array(client, SSD1307FB_COMMAND, cmd, len);
+}
+
+static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
+{
+        return ssd1307fb_write_cmd_array(client, &cmd, 1);
+}
+
+static inline int ssd1307fb_write_data_array(struct i2c_client *client, u8 *cmd, u32 len)
+{
+        return ssd1307fb_write_array(client, SSD1307FB_DATA, cmd, len);
+}
+
+static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data)
+{
+        return ssd1307fb_write_data_array(client, &data, 1);
+}
+
+static void ssd1307fb_update_display(struct ssd1307fb_par *par)
+{
+        u8 *vmem = par->info->screen_base;
+        int i, j, k;
+
+        /*
+         * The screen is divided in pages, each having a height of 8
+         * pixels, and the width of the screen. When sending a byte of
+         * data to the controller, it gives the 8 bits for the current
+         * column. I.e, the first byte are the 8 bits of the first
+         * column, then the 8 bits for the second column, etc.
+         *
+         *
+         * Representation of the screen, assuming it is 5 bits
+         * wide. Each letter-number combination is a bit that controls
+         * one pixel.
+         *
+         * A0 A1 A2 A3 A4
+         * B0 B1 B2 B3 B4
+         * C0 C1 C2 C3 C4
+         * D0 D1 D2 D3 D4
+         * E0 E1 E2 E3 E4
+         * F0 F1 F2 F3 F4
+         * G0 G1 G2 G3 G4
+         * H0 H1 H2 H3 H4
+         *
+         * If you want to update this screen, you need to send 5 bytes:
+         *  (1) A0 B0 C0 D0 E0 F0 G0 H0
+         *  (2) A1 B1 C1 D1 E1 F1 G1 H1
+         *  (3) A2 B2 C2 D2 E2 F2 G2 H2
+         *  (4) A3 B3 C3 D3 E3 F3 G3 H3
+         *  (5) A4 B4 C4 D4 E4 F4 G4 H4
+         */
+
+        for (i = 0; i < (SSD1307FB_HEIGHT / 8); i++) {
+                ssd1307fb_write_cmd(par->client, SSD1307FB_START_PAGE_ADDRESS + (i + 1));
+                ssd1307fb_write_cmd(par->client, 0x00);
+                ssd1307fb_write_cmd(par->client, 0x10);
+
+                for (j = 0; j < SSD1307FB_WIDTH; j++) {
+                        u8 buf = 0;
+                        for (k = 0; k < 8; k++) {
+                                u32 page_length = SSD1307FB_WIDTH * i;
+                                u32 index = page_length + (SSD1307FB_WIDTH * k + j) / 8;
+                                u8 byte = *(vmem + index);
+                                u8 bit = byte & (1 << (7 - (j % 8)));
+                                bit = bit >> (7 - (j % 8));
+                                buf |= bit << k;
+                        }
+                        ssd1307fb_write_data(par->client, buf);
+                }
+        }
+}
+
+
+static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
+                size_t count, loff_t *ppos)
+{
+        struct ssd1307fb_par *par = info->par;
+        unsigned long total_size;
+        unsigned long p = *ppos;
+        u8 __iomem *dst;
+
+        total_size = info->fix.smem_len;
+
+        if (p > total_size)
+                return -EINVAL;
+
+        if (count + p > total_size)
+                count = total_size - p;
+
+        if (!count)
+                return -EINVAL;
+
+        dst = (void __force *) (info->screen_base + p);
+
+        if (copy_from_user(dst, buf, count))
+                return -EFAULT;
+
+        ssd1307fb_update_display(par);
+
+        *ppos += count;
+
+        return count;
+}
+
+static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+        struct ssd1307fb_par *par = info->par;
+        sys_fillrect(info, rect);
+        ssd1307fb_update_display(par);
+}
+
+static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+        struct ssd1307fb_par *par = info->par;
+        sys_copyarea(info, area);
+        ssd1307fb_update_display(par);
+}
+
+static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+        struct ssd1307fb_par *par = info->par;
+        sys_imageblit(info, image);
+        ssd1307fb_update_display(par);
+}
+
+static struct fb_ops ssd1307fb_ops = {
+        .owner          = THIS_MODULE,
+        .fb_read        = fb_sys_read,
+        .fb_write       = ssd1307fb_write,
+        .fb_fillrect    = ssd1307fb_fillrect,
+        .fb_copyarea    = ssd1307fb_copyarea,
+        .fb_imageblit   = ssd1307fb_imageblit,
+};
+
+static void ssd1307fb_deferred_io(struct fb_info *info,
+                                struct list_head *pagelist)
+{
+        ssd1307fb_update_display(info->par);
+}
+
+static struct fb_deferred_io ssd1307fb_defio = {
+        .delay          = HZ,
+        .deferred_io    = ssd1307fb_deferred_io,
+};
+
+static int __devinit ssd1307fb_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+        struct fb_info *info;
+        u32 vmem_size = SSD1307FB_WIDTH * SSD1307FB_HEIGHT / 8;
+        struct ssd1307fb_par *par;
+        u8 *vmem;
+        int ret;
+
+        if (!client->dev.of_node) {
+                dev_err(&client->dev, "No device tree data found!\n");
+                return -EINVAL;
+        }
+
+        info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
+        if (!info) {
+                dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
+                return -ENOMEM;
+        }
+
+        vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
+        if (!vmem) {
+                dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
+                ret = -ENOMEM;
+                goto fb_alloc_error;
+        }
+
+        info->fbops = &ssd1307fb_ops;
+        info->fix = ssd1307fb_fix;
+        info->fbdefio = &ssd1307fb_defio;
+
+        info->var = ssd1307fb_var;
+        info->var.red.length = 1;
+        info->var.red.offset = 0;
+        info->var.green.length = 1;
+        info->var.green.offset = 0;
+        info->var.blue.length = 1;
+        info->var.blue.offset = 0;
+
+        info->screen_base = (u8 __force __iomem *)vmem;
+        info->fix.smem_start = (unsigned long)vmem;
+        info->fix.smem_len = vmem_size;
+
+        fb_deferred_io_init(info);
+
+        par = info->par;
+        par->info = info;
+        par->client = client;
+
+        par->reset = of_get_named_gpio(client->dev.of_node,
+                                         "reset-gpios", 0);
+        if (!gpio_is_valid(par->reset)) {
+                ret = -EINVAL;
+                goto reset_oled_error;
+        }
+
+        ret = devm_gpio_request_one(&client->dev, par->reset,
+                                    GPIOF_OUT_INIT_HIGH,
+                                    "oled-reset");
+        if (ret) {
+                dev_err(&client->dev,
+                        "failed to request gpio %d: %d\n",
+                        par->reset, ret);
+                goto reset_oled_error;
+        }
+
+        par->pwm = pwm_get(&client->dev, NULL);
+        if (IS_ERR(par->pwm)) {
+                dev_err(&client->dev, "Could not get PWM from device tree!\n");
+                ret = PTR_ERR(par->pwm);
+                goto pwm_error;
+        }
+
+        par->pwm_period = pwm_get_period(par->pwm);
+
+        dev_dbg(&client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period);
+
+        ret = register_framebuffer(info);
+        if (ret) {
+                dev_err(&client->dev, "Couldn't register the framebuffer\n");
+                goto fbreg_error;
+        }
+
+        i2c_set_clientdata(client, info);
+
+        /* Reset the screen */
+        gpio_set_value(par->reset, 0);
+        udelay(4);
+        gpio_set_value(par->reset, 1);
+        udelay(4);
+
+        /* Enable the PWM */
+        pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
+        pwm_enable(par->pwm);
+
+        /* Map column 127 of the OLED to segment 0 */
+        ret = ssd1307fb_write_cmd(client, SSD1307FB_SEG_REMAP_ON);
+        if (ret < 0) {
+                dev_err(&client->dev, "Couldn't remap the screen.\n");
+                goto remap_error;
+        }
+
+        /* Turn on the display */
+        ret = ssd1307fb_write_cmd(client, SSD1307FB_DISPLAY_ON);
+        if (ret < 0) {
+                dev_err(&client->dev, "Couldn't turn the display on.\n");
+                goto remap_error;
+        }
+
+        dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
+
+        return 0;
+
+remap_error:
+        unregister_framebuffer(info);
+        pwm_disable(par->pwm);
+fbreg_error:
+        pwm_put(par->pwm);
+pwm_error:
+reset_oled_error:
+        fb_deferred_io_cleanup(info);
+fb_alloc_error:
+        framebuffer_release(info);
+        return ret;
+}
+
+static int __devexit ssd1307fb_remove(struct i2c_client *client)
+{
+        struct fb_info *info = i2c_get_clientdata(client);
+        struct ssd1307fb_par *par = info->par;
+
+        unregister_framebuffer(info);
+        pwm_disable(par->pwm);
+        pwm_put(par->pwm);
+        fb_deferred_io_cleanup(info);
+        framebuffer_release(info);
+
+        return 0;
+}
+
+static const struct i2c_device_id ssd1307fb_i2c_id[] = {
+        { "ssd1307fb", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
+
+static const struct of_device_id ssd1307fb_of_match[] = {
+        { .compatible = "solomon,ssd1307fb-i2c" },
+        {},
+};
+MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
+
+static struct i2c_driver ssd1307fb_driver = {
+        .probe = ssd1307fb_probe,
+        .remove = __devexit_p(ssd1307fb_remove),
+        .id_table = ssd1307fb_i2c_id,
+        .driver = {
+                .name = "ssd1307fb",
+                .of_match_table = of_match_ptr(ssd1307fb_of_match),
+                .owner = THIS_MODULE,
+        },
+};
+
+module_i2c_driver(ssd1307fb_driver);
+
+MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controler");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_LICENSE("GPL");