Hi Thomas, On Mon, Mar 16, 2015 at 06:11:52PM +0100, Thomas Niederprüm wrote: > The 130X controllers are very similar from the configuration point of view. > The configuration registers for the SSD1305/6/7 are bit identical (except the > the VHCOM register and the the default values for clock setup register). This > patch unifies the init code of the controller and adds hardware specific > properties to DT that are needed to correctly initialize the device. > > The SSD130X can be wired to the OLED panel in various ways. Even for the > same controller this wiring can differ from one display module to another > and can not be probed by software. The added DT properties reflect these > hardware decisions of the display module manufacturer. > The 'com-sequential', 'com-lrremap' and 'com-invdir' values define different > possibilities for the COM signals pin configuration and readout direction > of the video memory. The 'segment-no-remap' allows the inversion of the > memory-to-pin mapping ultimately inverting the order of the controllers > output pins. The 'prechargepX' values need to be adapted according the > capacitance of the OLEDs pixel cells. > > So far these hardware specific bits are hard coded in the init code, making > the driver usable only for one certain wiring of the controller. This patch > makes the driver usable with all possible hardware setups, given a valid hw > description in DT. If these values are not set in DT the default values, > as they are set in the ssd1307 init code right now, are used. This implies > that without the corresponding DT property "segment-no-remap" the segment > remap of the ssd130X controller gets activated. Even though this is not the > default behaviour according to the datasheet it maintains backward > compatibility with older DTBs. > > Note that the SSD1306 does not seem to be using the configuration written to > the registers at all. Therefore this patch does not try to maintain these > values without changes in DT. For reference an example is added to the DT > bindings documentation that reproduces the configuration that is set in the > current init code. > > Signed-off-by: Thomas Niederprüm This looks mostly fine, thanks for your effort on this. > --- > .../devicetree/bindings/video/ssd1307fb.txt | 21 +++ > drivers/video/fbdev/ssd1307fb.c | 195 ++++++++++++--------- > 2 files changed, 137 insertions(+), 79 deletions(-) > > diff --git a/Documentation/devicetree/bindings/video/ssd1307fb.txt b/Documentation/devicetree/bindings/video/ssd1307fb.txt > index 7a12542..be27562 100644 > --- a/Documentation/devicetree/bindings/video/ssd1307fb.txt > +++ b/Documentation/devicetree/bindings/video/ssd1307fb.txt > @@ -15,6 +15,16 @@ Required properties: > > Optional properties: > - reset-active-low: Is the reset gpio is active on physical low? > + - solomon,segment-no-remap: Display needs normal (non-inverted) data column > + to segment mapping > + - solomon,com-sequential: Display uses sequential COM pin configuration > + - solomon,com-lrremap: Display uses left-right COM pin remap > + - solomon,com-invdir: Display uses inverted COM pin scan direction > + - solomon,com-offset: Offset of the first COM pin wired to the panel Documenting the offset unit would be fine. > + - solomon,prechargep1: Length of deselect period (phase 1) in clock cycles. > + - solomon,prechargep2: Length of precharge period (phase 2) in clock cycles. > + This needs to be the higher, the higher the capacitance > + of the OLED's pixels is > > [0]: Documentation/devicetree/bindings/pwm/pwm.txt > > @@ -26,3 +36,14 @@ ssd1307: oled@3c { > reset-gpios = <&gpio2 7>; > reset-active-low; > }; > + > +ssd1306: oled@3c { > + compatible = "solomon,ssd1306fb-i2c"; > + reg = <0x3c>; > + pwms = <&pwm 4 3000>; > + reset-gpios = <&gpio2 7>; > + reset-active-low; > + solomon,com-lrremap; > + solomon,com-invdir; > + solomon,com-offset = <32>; > +}; > diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c > index 8d34c56..9a66118 100644 > --- a/drivers/video/fbdev/ssd1307fb.c > +++ b/drivers/video/fbdev/ssd1307fb.c > @@ -16,6 +16,9 @@ > #include > #include > > +#define DEVID_SSD1306 6 > +#define DEVID_SSD1307 7 > + > #define SSD1307FB_DATA 0x40 > #define SSD1307FB_COMMAND 0x80 > > @@ -38,22 +41,38 @@ > #define SSD1307FB_SET_COM_PINS_CONFIG 0xda > #define SSD1307FB_SET_VCOMH 0xdb > > +static u_int contrast = 128; > +module_param(contrast, uint, S_IRUGO); > + Why is this patch adding a contrast parameter? You don't even mention it in your commit log. This should be a separate patch. > struct ssd1307fb_par; > > -struct ssd1307fb_ops { > - int (*init)(struct ssd1307fb_par *); > - int (*remove)(struct ssd1307fb_par *); > +struct ssd1307fb_deviceinfo { > + int device_id; > + u32 default_vcomh; > + u32 default_dclk_div; > + u32 default_dclk_frq; > }; > > struct ssd1307fb_par { > + u32 com_invdir; > + u32 com_lrremap; > + u32 com_offset; > + u32 com_seq; > + u32 contrast; > + u32 dclk_div; > + u32 dclk_frq; > + struct ssd1307fb_deviceinfo *device_info; > struct i2c_client *client; > u32 height; > struct fb_info *info; > - struct ssd1307fb_ops *ops; > u32 page_offset; > + u32 prechargep1; > + u32 prechargep2; > struct pwm_device *pwm; > u32 pwm_period; > int reset; > + u32 seg_remap; > + u32 vcomh; > u32 width; > }; > > @@ -254,69 +273,46 @@ static struct fb_deferred_io ssd1307fb_defio = { > .deferred_io = ssd1307fb_deferred_io, > }; > > -static int ssd1307fb_ssd1307_init(struct ssd1307fb_par *par) > +static int ssd1307fb_init(struct ssd1307fb_par *par) > { > int ret; > + u32 precharge, dclk, com_invdir, compins; > > - par->pwm = pwm_get(&par->client->dev, NULL); > - if (IS_ERR(par->pwm)) { > - dev_err(&par->client->dev, "Could not get PWM from device tree!\n"); > - return PTR_ERR(par->pwm); > - } > - > - par->pwm_period = pwm_get_period(par->pwm); > - /* Enable the PWM */ > - pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period); > - pwm_enable(par->pwm); > - > - dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n", > - par->pwm->pwm, par->pwm_period); > - > - /* Map column 127 of the OLED to segment 0 */ > - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); > - if (ret < 0) > - return ret; > - > - /* Turn on the display */ > - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); > - if (ret < 0) > - return ret; > - > - return 0; > -} > - > -static int ssd1307fb_ssd1307_remove(struct ssd1307fb_par *par) > -{ > - pwm_disable(par->pwm); > - pwm_put(par->pwm); > - return 0; > -} > + if (par->device_info->device_id == DEVID_SSD1307) { > + par->pwm = pwm_get(&par->client->dev, NULL); > + if (IS_ERR(par->pwm)) { > + dev_err(&par->client->dev, "Could not get PWM from device tree!\n"); > + return PTR_ERR(par->pwm); > + } > > -static struct ssd1307fb_ops ssd1307fb_ssd1307_ops = { > - .init = ssd1307fb_ssd1307_init, > - .remove = ssd1307fb_ssd1307_remove, > -}; > + par->pwm_period = pwm_get_period(par->pwm); > + /* Enable the PWM */ > + pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period); > + pwm_enable(par->pwm); > > -static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > -{ > - int ret; > + dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n", > + par->pwm->pwm, par->pwm_period); > + }; > > /* Set initial contrast */ > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST); > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x7f); > - if (ret < 0) > - return ret; > - > - /* Set COM direction */ > - ret = ssd1307fb_write_cmd(par->client, 0xc8); > + ret = ssd1307fb_write_cmd(par->client, par->contrast); > if (ret < 0) > return ret; > > /* Set segment re-map */ > - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); > + if (par->seg_remap) { > + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON); > + if (ret < 0) > + return ret; > + }; > + > + /* Set COM direction */ > + com_invdir = 0xc0 | (par->com_invdir & 0xf) << 3; > + ret = ssd1307fb_write_cmd(par->client, com_invdir); > if (ret < 0) > return ret; > > @@ -334,34 +330,38 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x20); > + ret = ssd1307fb_write_cmd(par->client, par->com_offset); > if (ret < 0) > return ret; > > /* Set clock frequency */ > + dclk = (par->dclk_div & 0xf) | (par->dclk_frq & 0xf) << 4; > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ); > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0xf0); > + ret = ssd1307fb_write_cmd(par->client, dclk); It would make more sense to assign the variable where you use it. > if (ret < 0) > return ret; > > /* Set precharge period in number of ticks from the internal clock */ > + precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4; > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD); > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x22); > + ret = ssd1307fb_write_cmd(par->client, precharge); Here too. > if (ret < 0) > return ret; > > /* Set COM pins configuration */ > + compins = 0x02 | (!par->com_seq & 0x1) << 4 > + | (par->com_lrremap & 0x1) << 5; > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG); > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x22); > + ret = ssd1307fb_write_cmd(par->client, compins); And here. > if (ret < 0) > return ret; > > @@ -370,18 +370,20 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > if (ret < 0) > return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x49); > + ret = ssd1307fb_write_cmd(par->client, par->vcomh); > if (ret < 0) > return ret; > > - /* Turn on the DC-DC Charge Pump */ > - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP); > - if (ret < 0) > - return ret; > + if (par->device_info->device_id == DEVID_SSD1306) { > + /* Turn on the DC-DC Charge Pump */ > + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP); > + if (ret < 0) > + return ret; > > - ret = ssd1307fb_write_cmd(par->client, 0x14); > - if (ret < 0) > - return ret; > + ret = ssd1307fb_write_cmd(par->client, 0x14); > + if (ret < 0) > + return ret; > + }; > > /* Switch to horizontal addressing mode */ > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE); > @@ -393,6 +395,7 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > if (ret < 0) > return ret; > > + /* Set column range */ The indentation is wrong. > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); > if (ret < 0) > return ret; > @@ -405,6 +408,7 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > if (ret < 0) > return ret; > > + /* Set page range */ Here too. > ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); > if (ret < 0) > return ret; > @@ -426,18 +430,28 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par) > return 0; > } > > -static struct ssd1307fb_ops ssd1307fb_ssd1306_ops = { > - .init = ssd1307fb_ssd1306_init, > +static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = { > + .device_id = DEVID_SSD1306, > + .default_vcomh = 0x20, > + .default_dclk_div = 0, > + .default_dclk_frq = 8, > +}; > + > +static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = { > + .device_id = DEVID_SSD1307, > + .default_vcomh = 0x20, > + .default_dclk_div = 1, > + .default_dclk_frq = 12, > }; > > static const struct of_device_id ssd1307fb_of_match[] = { > { > .compatible = "solomon,ssd1306fb-i2c", > - .data = (void *)&ssd1307fb_ssd1306_ops, > + .data = (void *)&ssd1307fb_ssd1306_deviceinfo, > }, > { > .compatible = "solomon,ssd1307fb-i2c", > - .data = (void *)&ssd1307fb_ssd1307_ops, > + .data = (void *)&ssd1307fb_ssd1307_deviceinfo, Do we need this ID? Wouldn't it make more sense to pass the pointer to the struct we need to use? > }, > {}, > }; > @@ -468,8 +482,8 @@ static int ssd1307fb_probe(struct i2c_client *client, > par->info = info; > par->client = client; > > - par->ops = (struct ssd1307fb_ops *)of_match_device(ssd1307fb_of_match, > - &client->dev)->data; > + par->device_info = (struct ssd1307fb_deviceinfo *)of_match_device( > + ssd1307fb_of_match, &client->dev)->data; > > par->reset = of_get_named_gpio(client->dev.of_node, > "reset-gpios", 0); > @@ -487,6 +501,27 @@ static int ssd1307fb_probe(struct i2c_client *client, > if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset)) > par->page_offset = 1; > > + if (of_property_read_u32(node, "solomon,com-offset", &par->com_offset)) > + par->com_offset = 0; > + > + if (of_property_read_u32(node, "solomon,prechargep1", &par->prechargep1)) > + par->prechargep1 = 2; > + > + if (of_property_read_u32(node, "solomon,prechargep2", &par->prechargep2)) > + par->prechargep2 = 0; > + > + par->seg_remap = !of_property_read_bool(node, "solomon,segment-no-remap"); > + par->com_seq = of_property_read_bool(node, "solomon,com-sequential"); > + par->com_lrremap = of_property_read_bool(node, "solomon,com-lrremap"); > + par->com_invdir = of_property_read_bool(node, "solomon,com-invdir"); > + > + par->contrast = contrast; > + par->vcomh = par->device_info->default_vcomh; > + > + /* Setup display timing */ > + par->dclk_div = par->device_info->default_dclk_div; > + par->dclk_frq = par->device_info->default_dclk_frq; > + > vmem_size = par->width * par->height / 8; > > vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, > @@ -539,11 +574,9 @@ static int ssd1307fb_probe(struct i2c_client *client, > gpio_set_value(par->reset, 1); > udelay(4); > > - if (par->ops->init) { > - ret = par->ops->init(par); > - if (ret) > - goto reset_oled_error; > - } > + ret = ssd1307fb_init(par); > + if (ret) > + goto reset_oled_error; > > ret = register_framebuffer(info); > if (ret) { > @@ -556,8 +589,10 @@ static int ssd1307fb_probe(struct i2c_client *client, > return 0; > > panel_init_error: > - if (par->ops->remove) > - par->ops->remove(par); > + if (par->device_info->device_id == DEVID_SSD1307) { > + pwm_disable(par->pwm); > + pwm_put(par->pwm); > + }; > reset_oled_error: > fb_deferred_io_cleanup(info); > fb_alloc_error: > @@ -571,8 +606,10 @@ static int ssd1307fb_remove(struct i2c_client *client) > struct ssd1307fb_par *par = info->par; > > unregister_framebuffer(info); > - if (par->ops->remove) > - par->ops->remove(par); > + if (par->device_info->device_id == DEVID_SSD1307) { > + pwm_disable(par->pwm); > + pwm_put(par->pwm); > + }; > fb_deferred_io_cleanup(info); > __free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len)); > framebuffer_release(info); > -- > 2.3.0 > Thanks, Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com