| Message ID | 1343730576-20494-2-git-send-email-maxime.ripard@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Maxim, On Tue, Jul 31, 2012 at 3:59 PM, Maxime Ripard < maxime.ripard@free-electrons.com> wrote: > This patch adds support for the Solomon SSD1307 OLED > controller found on the Crystalfontz CFA10036 board. > > This controller can drive a display with a resolution up > to 128x39 and can operate over I2C or SPI. > > The current driver has only been tested on the CFA-10036, > that is using this controller over I2C to driver a 96x16 > OLED screen. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > Cc: Brian Lilly <brian@crystalfontz.com> > --- > .../devicetree/bindings/video/ssd1307fb.txt | 24 ++ > drivers/video/Kconfig | 14 + > drivers/video/Makefile | 1 + > drivers/video/ssd1307fb.c | 418 > ++++++++++++++++++++ > 4 files changed, 457 insertions(+) > create mode 100644 Documentation/devicetree/bindings/video/ssd1307fb.txt > create mode 100644 drivers/video/ssd1307fb.c > > diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt > b/Documentation/devicetree/bindings/video/ssd1307fb.txt > new file mode 100644 > index 0000000..791e14f > --- /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] > + - oled-reset-gpio: Should contain the GPIO used to reset the OLED > display > + > +Optional properties: > + - oled-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>; > + oled-reset-gpio = <&gpio2 7 1>; > + oled-reset-active-low; > +}; > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig > index 0217f74..21ae6dd 100644 > --- a/drivers/video/Kconfig > +++ b/drivers/video/Kconfig > @@ -2469,4 +2469,18 @@ 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 > + 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 ee8dafb..6bbb72c 100644 > --- a/drivers/video/Makefile > +++ b/drivers/video/Makefile > @@ -164,6 +164,7 @@ 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 0000000..c705ab4 > --- /dev/null > +++ b/drivers/video/ssd1307fb.c > @@ -0,0 +1,418 @@ > +/* > + * 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"); > + ret = -ENOMEM; > + goto out; > Why cant we just return from here with -ENOMEM directly rather than jumping to a label, which again just returns? > + } > + > + 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); > +out: > + 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 int ssd1307fb_set(struct i2c_client *client, u8 value) > +{ > + int i, j, ret; > + > + for (i = 1; i <= (SSD1307FB_HEIGHT / 8); i++) { > + ret = ssd1307fb_write_cmd(client, > SSD1307FB_START_PAGE_ADDRESS + i); > + if (ret < 0) > + goto i2c_error; > + > + ret = ssd1307fb_write_cmd(client, 0x00); > + if (ret < 0) > + goto i2c_error; > + > + ret = ssd1307fb_write_cmd(client, 0x10); > + if (ret < 0) > + goto i2c_error; > + > + for (j = 0; j < SSD1307FB_WIDTH; j++) > + ssd1307fb_write_data(client, value); > + } > + > + return 0; > + > +i2c_error: > + dev_err(&client->dev, "Couldn't send i2c command: %d\n", ret); > + return ret; > +} > + > +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); > + } > + } > + > + return; > 'return' not required? > +} > + > + > +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 p = *ppos; > + void *dst; > + int err = 0; > + > + dst = (void __force *) (info->screen_base + p); > + > + if (copy_from_user(dst, buf, count)) > + err = -EFAULT; > + > + if (!err) > + *ppos += count; > + > + ssd1307fb_update_display(par); > + > + return (err) ? err : 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"); > + ret = -EINVAL; > + goto generic_error; > Again, can just return from here with the error value... > + } > + > + info = framebuffer_alloc(sizeof(struct ssd1307fb_par), > &client->dev); > + if (!info) { > + ret = -ENOMEM; > + goto generic_error; > ditto > + } > + > + vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL); > + if (!vmem) { > + dev_err(&client->dev, "Couldn't allocate graphical > memory.\n"); > + ret = -ENOMEM; > + goto generic_error; > ditto > + } > + > + 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, > + "oled-reset-gpio", 0); > + if (gpio_is_valid(par->reset)) { > + int flags = GPIOF_OUT_INIT_HIGH; > + if (of_get_property(client->dev.of_node, > + "oled-reset-active-low", NULL)) > + flags = GPIOF_OUT_INIT_LOW; > + ret = devm_gpio_request_one(&client->dev, par->reset, > + flags, "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, 1); > + udelay(4); > + gpio_set_value(par->reset, 0); > + 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); > + framebuffer_release(info); > +generic_error: > + 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"); > -- > 1.7.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel Regards, -Amar
On Tue, Jul 31, 2012 at 12:29:33PM +0200, Maxime Ripard wrote: > +Optional properties: > + - oled-reset-active-low: Is the reset gpio is active on physical low? You may want to take a look at commit c1cb438 (bindings: update imx and mxs #gpio-cells) which got merged recently. In case the driver will only work on mxs, this optional property can just be dropped. Regards, Shawn
On Tuesday, July 31, 2012 7:30 PM Maxime Ripard wrote: > > This patch adds support for the Solomon SSD1307 OLED > controller found on the Crystalfontz CFA10036 board. > > This controller can drive a display with a resolution up > to 128x39 and can operate over I2C or SPI. > > The current driver has only been tested on the CFA-10036, > that is using this controller over I2C to driver a 96x16 > OLED screen. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > Cc: Brian Lilly <brian@crystalfontz.com> > --- > .../devicetree/bindings/video/ssd1307fb.txt | 24 ++ > drivers/video/Kconfig | 14 + > drivers/video/Makefile | 1 + > drivers/video/ssd1307fb.c | 418 ++++++++++++++++++++ > 4 files changed, 457 insertions(+) > create mode 100644 Documentation/devicetree/bindings/video/ssd1307fb.txt > create mode 100644 drivers/video/ssd1307fb.c > > diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt > b/Documentation/devicetree/bindings/video/ssd1307fb.txt > new file mode 100644 > index 0000000..791e14f > --- /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] > + - oled-reset-gpio: Should contain the GPIO used to reset the OLED display > + > +Optional properties: > + - oled-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>; > + oled-reset-gpio = <&gpio2 7 1>; > + oled-reset-active-low; > +}; > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig > index 0217f74..21ae6dd 100644 > --- a/drivers/video/Kconfig > +++ b/drivers/video/Kconfig > @@ -2469,4 +2469,18 @@ config FB_SH_MOBILE_MERAM > Up to 4 memory channels can be configured, allowing 4 RGB or > 2 YCbCr framebuffers to be configured. > > + Please remove redundant line. > +config FB_SSD1307 > + tristate "Solomon SSD1307 framebuffer support" > + depends on FB && I2C > + 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 ee8dafb..6bbb72c 100644 > --- a/drivers/video/Makefile > +++ b/drivers/video/Makefile > @@ -164,6 +164,7 @@ 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 0000000..c705ab4 > --- /dev/null > +++ b/drivers/video/ssd1307fb.c > @@ -0,0 +1,418 @@ > +/* > + * 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"); > + ret = -ENOMEM; > + goto out; > + } How about using returning - ENOMEM without goto. It is simpler. 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); > +out: > + return ret; Please refer to above comment. If goto out is not used, it would be simpler. +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 int ssd1307fb_set(struct i2c_client *client, u8 value) > +{ > + int i, j, ret; > + > + for (i = 1; i <= (SSD1307FB_HEIGHT / 8); i++) { > + ret = ssd1307fb_write_cmd(client, SSD1307FB_START_PAGE_ADDRESS + i); > + if (ret < 0) > + goto i2c_error; > + > + ret = ssd1307fb_write_cmd(client, 0x00); > + if (ret < 0) > + goto i2c_error; > + > + ret = ssd1307fb_write_cmd(client, 0x10); > + if (ret < 0) > + goto i2c_error; > + > + for (j = 0; j < SSD1307FB_WIDTH; j++) > + ssd1307fb_write_data(client, value); > + } > + > + return 0; > + > +i2c_error: > + dev_err(&client->dev, "Couldn't send i2c command: %d\n", ret); > + return ret; > +} > + > +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); > + } > + } > + > + return; > +} > + > + Please remove unnecessary line. > +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 p = *ppos; > + void *dst; > + int err = 0; > + > + dst = (void __force *) (info->screen_base + p); > + > + if (copy_from_user(dst, buf, count)) > + err = -EFAULT; > + > + if (!err) > + *ppos += count; > + > + ssd1307fb_update_display(par); > + > + return (err) ? err : 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"); > + ret = -EINVAL; > + goto generic_error; > + } How about using returning -EINVAL without goto. It is simpler. 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) { > + ret = -ENOMEM; > + goto generic_error; > + } Ditto. > + > + vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL); > + if (!vmem) { > + dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); > + ret = -ENOMEM; > + goto generic_error; > + } Please fix this 'goto generic_error'. goto generic_error cannot call framebuffer_release(). If framebuffer_alloc() is already called, framebuffer_release() should be called when error happens. > + > + 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, > + "oled-reset-gpio", 0); > + if (gpio_is_valid(par->reset)) { > + int flags = GPIOF_OUT_INIT_HIGH; > + if (of_get_property(client->dev.of_node, > + "oled-reset-active-low", NULL)) > + flags = GPIOF_OUT_INIT_LOW; > + ret = devm_gpio_request_one(&client->dev, par->reset, > + flags, "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, 1); > + udelay(4); > + gpio_set_value(par->reset, 0); > + 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); > + framebuffer_release(info); > +generic_error: > + 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; How about insert new line between variables and functions to enhance the readability? > + 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"); > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Shawn, Le 01/08/2012 07:24, Shawn Guo a écrit : > On Tue, Jul 31, 2012 at 12:29:33PM +0200, Maxime Ripard wrote: >> +Optional properties: >> + - oled-reset-active-low: Is the reset gpio is active on physical low? > > You may want to take a look at commit c1cb438 (bindings: update imx and > mxs #gpio-cells) which got merged recently. In case the driver will > only work on mxs, this optional property can just be dropped. Thanks for the tip. However, I'm not sure this device will be mxs specific, since this controller is used on some other devices as well (I know for example that some uses it with the Arduino, even though it's not related to Linux), so relying on mxs-specific capabilities here might not be that great. But since it's only for a mxs board for now, maybe we can rely on this and add a dt parameter if we need it in the future. I don't know, both make sense I guess. Maxime
On Wed, Aug 01, 2012 at 12:28:27PM +0200, Maxime Ripard wrote: > Thanks for the tip. > However, I'm not sure this device will be mxs specific, since this > controller is used on some other devices as well (I know for example > that some uses it with the Arduino, even though it's not related to > Linux), so relying on mxs-specific capabilities here might not be that > great. > Ok, agreed. In that case, putting "1" in last cell of oled-reset-gpio does not make any point then. +Examples: +ssd1307: oled@3c { + compatible = "solomon,ssd1307fb-i2c"; + reg = <0x3c>; + pwms = <&pwm 4 3000>; + oled-reset-gpio = <&gpio2 7 1>; + oled-reset-active-low; +};
Le 02/08/2012 02:34, Shawn Guo a écrit : > On Wed, Aug 01, 2012 at 12:28:27PM +0200, Maxime Ripard wrote: >> Thanks for the tip. >> However, I'm not sure this device will be mxs specific, since this >> controller is used on some other devices as well (I know for example >> that some uses it with the Arduino, even though it's not related to >> Linux), so relying on mxs-specific capabilities here might not be that >> great. >> > Ok, agreed. In that case, putting "1" in last cell of oled-reset-gpio > does not make any point then. > > +Examples: > +ssd1307: oled@3c { > + compatible = "solomon,ssd1307fb-i2c"; > + reg = <0x3c>; > + pwms = <&pwm 4 3000>; > + oled-reset-gpio = <&gpio2 7 1>; > + oled-reset-active-low; > +}; > Ok, I will do that then. Maxime
diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt b/Documentation/devicetree/bindings/video/ssd1307fb.txt new file mode 100644 index 0000000..791e14f --- /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] + - oled-reset-gpio: Should contain the GPIO used to reset the OLED display + +Optional properties: + - oled-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>; + oled-reset-gpio = <&gpio2 7 1>; + oled-reset-active-low; +}; diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 0217f74..21ae6dd 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -2469,4 +2469,18 @@ 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 + 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 ee8dafb..6bbb72c 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -164,6 +164,7 @@ 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 0000000..c705ab4 --- /dev/null +++ b/drivers/video/ssd1307fb.c @@ -0,0 +1,418 @@ +/* + * 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"); + ret = -ENOMEM; + goto out; + } + + 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); +out: + 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 int ssd1307fb_set(struct i2c_client *client, u8 value) +{ + int i, j, ret; + + for (i = 1; i <= (SSD1307FB_HEIGHT / 8); i++) { + ret = ssd1307fb_write_cmd(client, SSD1307FB_START_PAGE_ADDRESS + i); + if (ret < 0) + goto i2c_error; + + ret = ssd1307fb_write_cmd(client, 0x00); + if (ret < 0) + goto i2c_error; + + ret = ssd1307fb_write_cmd(client, 0x10); + if (ret < 0) + goto i2c_error; + + for (j = 0; j < SSD1307FB_WIDTH; j++) + ssd1307fb_write_data(client, value); + } + + return 0; + +i2c_error: + dev_err(&client->dev, "Couldn't send i2c command: %d\n", ret); + return ret; +} + +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); + } + } + + return; +} + + +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 p = *ppos; + void *dst; + int err = 0; + + dst = (void __force *) (info->screen_base + p); + + if (copy_from_user(dst, buf, count)) + err = -EFAULT; + + if (!err) + *ppos += count; + + ssd1307fb_update_display(par); + + return (err) ? err : 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"); + ret = -EINVAL; + goto generic_error; + } + + info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev); + if (!info) { + ret = -ENOMEM; + goto generic_error; + } + + vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL); + if (!vmem) { + dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); + ret = -ENOMEM; + goto generic_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, + "oled-reset-gpio", 0); + if (gpio_is_valid(par->reset)) { + int flags = GPIOF_OUT_INIT_HIGH; + if (of_get_property(client->dev.of_node, + "oled-reset-active-low", NULL)) + flags = GPIOF_OUT_INIT_LOW; + ret = devm_gpio_request_one(&client->dev, par->reset, + flags, "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, 1); + udelay(4); + gpio_set_value(par->reset, 0); + 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); + framebuffer_release(info); +generic_error: + 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");
This patch adds support for the Solomon SSD1307 OLED controller found on the Crystalfontz CFA10036 board. This controller can drive a display with a resolution up to 128x39 and can operate over I2C or SPI. The current driver has only been tested on the CFA-10036, that is using this controller over I2C to driver a 96x16 OLED screen. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Brian Lilly <brian@crystalfontz.com> --- .../devicetree/bindings/video/ssd1307fb.txt | 24 ++ drivers/video/Kconfig | 14 + drivers/video/Makefile | 1 + drivers/video/ssd1307fb.c | 418 ++++++++++++++++++++ 4 files changed, 457 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/ssd1307fb.txt create mode 100644 drivers/video/ssd1307fb.c