From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by casper.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cicfd-0007uq-G0 for barebox@lists.infradead.org; Tue, 28 Feb 2017 07:58:07 +0000 Date: Tue, 28 Feb 2017 08:57:42 +0100 From: Sascha Hauer Message-ID: <20170228075742.p2p6in2mucfsjvkl@pengutronix.de> References: <20170224142501.2679-1-bst@pengutronix.de> <20170224142501.2679-5-bst@pengutronix.de> <20170227100850.dv7kxvyxhutqfra6@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 4/4] video: add support for Solomon SSD1307 OLED controller family To: Bastian Stender Cc: barebox@lists.infradead.org On Mon, Feb 27, 2017 at 04:45:43PM +0100, Bastian Stender wrote: > 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@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 > > > --- > > > 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 , Free Electrons > > > + * > > > + * Ported to barebox from linux v4.10 > > > + * Copyright (C) 2017 Pengutronix, Bastian Stender > > > + * > > > + * Licensed under the GPLv2 or later. > > > + */ > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#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 Ok. > > > > > > + > > > + 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? Yes, please. The resolution of the framebuffer must be explicitly given in the device tree. If it's not then the user gets a better clue what's wrong when the driver does not successfully probe. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox