[PATCH 4/4] video: add support for Solomon SSD1307 OLED controller family
Bastian Stender
bst at pengutronix.de
Mon Feb 27 07:45:43 PST 2017
On 02/27/2017 11:08 AM, Sascha Hauer wrote:
> On Fri, Feb 24, 2017 at 03:25:01PM +0100, Bastian Stender wrote:
>> It was ported from linux v4.10. Like the kernel driver only
>> communication via I2C is supported.
>>
>> It has only been tested with a SSD1306 and a 96x16 OLED display:
>>
>> &i2c0 {
>> status = "okay";
>>
>> ssd1306: oled at 3c {
>> compatible = "solomon,ssd1306fb-i2c";
>> reg = <0x3c>;
>> reset-gpios = <&gpio1 1 0>;
>> solomon,height = <16>;
>> solomon,width = <96>;
>> solomon,page-offset = <0>;
>> solomon,com-invdir;
>> solomon,com-seq;
>> };
>>
>> Signed-off-by: Bastian Stender <bst at pengutronix.de>
>> ---
>> drivers/video/Kconfig | 4 +
>> drivers/video/Makefile | 1 +
>> drivers/video/ssd1307fb.c | 569 ++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 574 insertions(+)
>> create mode 100644 drivers/video/ssd1307fb.c
>>
>> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
>> index 8f31f5af74..50a876acb1 100644
>> --- a/drivers/video/Kconfig
>> +++ b/drivers/video/Kconfig
>> @@ -12,6 +12,10 @@ config FRAMEBUFFER_CONSOLE
>> select FONTS
>> prompt "framebuffer console support"
>>
>> +config DRIVER_VIDEO_FB_SSD1307
>> + bool "Solomon SSD1307 framebuffer support"
>> + depends on PWM && I2C && GPIOLIB
>> +
>> config VIDEO_VPL
>> depends on OFTREE
>> bool
>> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
>> index 1bf2e1f3ca..e23c9c37b6 100644
>> --- a/drivers/video/Makefile
>> +++ b/drivers/video/Makefile
>> @@ -21,3 +21,4 @@ obj-$(CONFIG_DRIVER_VIDEO_OMAP) += omap.o
>> obj-$(CONFIG_DRIVER_VIDEO_BCM283X) += bcm2835.o
>> obj-$(CONFIG_DRIVER_VIDEO_SIMPLEFB) += simplefb.o
>> obj-$(CONFIG_DRIVER_VIDEO_IMX_IPUV3) += imx-ipu-v3/
>> +obj-$(CONFIG_DRIVER_VIDEO_FB_SSD1307) += ssd1307fb.o
>> diff --git a/drivers/video/ssd1307fb.c b/drivers/video/ssd1307fb.c
>> new file mode 100644
>> index 0000000000..0dfdcc2232
>> --- /dev/null
>> +++ b/drivers/video/ssd1307fb.c
>> @@ -0,0 +1,569 @@
>> +/*
>> + * Driver for the Solomon SSD1307 OLED controller family
>> + *
>> + * Supports:
>> + * - SSD1305 (untested)
>> + * - SSD1306
>> + * - SSD1307 (untested)
>> + * - SSD1309 (untested)
>> + *
>> + * Copyright 2012 Maxime Ripard <maxime.ripard at free-electrons.com>, Free Electrons
>> + *
>> + * Ported to barebox from linux v4.10
>> + * Copyright (C) 2017 Pengutronix, Bastian Stender <kernel at pengutronix.de>
>> + *
>> + * Licensed under the GPLv2 or later.
>> + */
>> +
>> +#include <common.h>
>> +#include <init.h>
>> +#include <fb.h>
>> +#include <i2c/i2c.h>
>> +#include <of_device.h>
>> +#include <gpio.h>
>> +#include <of_gpio.h>
>> +#include <printk.h>
>> +
>> +#define SSD1307FB_DATA 0x40
>> +#define SSD1307FB_COMMAND 0x80
>> +
>> +#define SSD1307FB_SET_ADDRESS_MODE 0x20
>> +#define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL (0x00)
>> +#define SSD1307FB_SET_ADDRESS_MODE_VERTICAL (0x01)
>> +#define SSD1307FB_SET_ADDRESS_MODE_PAGE (0x02)
>> +#define SSD1307FB_SET_COL_RANGE 0x21
>> +#define SSD1307FB_SET_PAGE_RANGE 0x22
>> +#define SSD1307FB_CONTRAST 0x81
>> +#define SSD1307FB_CHARGE_PUMP 0x8d
>> +#define SSD1307FB_SEG_REMAP_ON 0xa1
>> +#define SSD1307FB_DISPLAY_OFF 0xae
>> +#define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8
>> +#define SSD1307FB_DISPLAY_ON 0xaf
>> +#define SSD1307FB_START_PAGE_ADDRESS 0xb0
>> +#define SSD1307FB_SET_DISPLAY_OFFSET 0xd3
>> +#define SSD1307FB_SET_CLOCK_FREQ 0xd5
>> +#define SSD1307FB_SET_PRECHARGE_PERIOD 0xd9
>> +#define SSD1307FB_SET_COM_PINS_CONFIG 0xda
>> +#define SSD1307FB_SET_VCOMH 0xdb
>
> please consistently use spaces after #define
Will do.
>
>> +
>> +struct ssd1307fb_par;
>
> Unnecessary.
Ok.
>
>> +
>> +struct ssd1307fb_deviceinfo {
>> + u32 default_vcomh;
>> + u32 default_dclk_div;
>> + u32 default_dclk_frq;
>> + int need_chargepump;
>> +};
>> +
>
> [...]
>
>> +static int ssd1307fb_probe(struct device_d *dev)
>> +{
>> + struct i2c_client *client = to_i2c_client(dev);
>> + struct fb_info *info;
>> + struct device_node *node = dev->device_node;
>> + const struct of_device_id *match =
>> + of_match_node(ssd1307fb_of_match, dev->device_node);
>> + u32 vmem_size;
>> + struct ssd1307fb_par *par;
>> + struct ssd1307fb_array *array;
>> + u8 *vmem;
>> + int ret;
>> + int i, j;
>> +
>> + if (!node) {
>> + dev_err(&client->dev, "No device tree data found!\n");
>> + return -EINVAL;
>> + }
>> +
>> + info = xzalloc(sizeof(struct fb_info));
>> + if (!info) {
>> + dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
>> + return -ENOMEM;
>> + }
>
> xzalloc always returns succesfully, no need to check.
Ok.
>
>> +
>> + par = info->priv;
>> + par->info = info;
>> + par->client = client;
>> +
>> + par->device_info = (struct ssd1307fb_deviceinfo *)match->data;
>> +
>> + par->reset = of_get_named_gpio(node,
>> + "reset-gpios", 0);
>> + if (!gpio_is_valid(par->reset)) {
>> + dev_err(&client->dev,
>> + "Couldn't get named gpio 'reset-gpios' %d.\n",
>> + par->reset);
>> + ret = par->reset;
>> + goto fb_alloc_error;
>> + }
>
> Is this gpio really mandatory?
This is the corresponding snippet from the kernel in
drivers/video/fbdev/ssd1307fb.c, line 564 ff. (v4.10):
par->reset = of_get_named_gpio(client->dev.of_node,
"reset-gpios", 0);
if (!gpio_is_valid(par->reset)) {
ret = -EINVAL;
goto fb_alloc_error;
}
"reset-gpios" is one of the required properties, see
Documentation/devicetree/bindings/display/ssd1307fb.txt
or in barebox:
dts/Bindings/display/ssd1307fb.txt
>
>> +
>> + if (of_property_read_u32(node, "solomon,width", &par->width))
>> + par->width = 96;
>> +
>> + if (of_property_read_u32(node, "solomon,height", &par->height))
>> + par->height = 16;
>
> These defaults only work for you. You should bail out with an error if
> the devicetree does not contain values for these instead.
This part was ported 1:1 from linux. As solomon,width and solomon,height
are required properties also, should I bail out nonetheless?
Regards,
Bastian
--
Pengutronix e.K.
Industrial Linux Solutions
http://www.pengutronix.de/
Peiner Str. 6-8, 31137 Hildesheim, Germany
Amtsgericht Hildesheim, HRA 2686
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