[deliverable/linux.git] / drivers / video / ssd1307fb.c

/*
 * 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");
Commit	Line	Data
a2ed00da MR	1	/*
	2	* Driver for the Solomon SSD1307 OLED controler
	3	*
	4	* Copyright 2012 Free Electrons
	5	*
	6	* Licensed under the GPLv2 or later.
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/kernel.h>
	11	#include <linux/i2c.h>
	12	#include <linux/fb.h>
	13	#include <linux/uaccess.h>
	14	#include <linux/of_device.h>
	15	#include <linux/of_gpio.h>
	16	#include <linux/pwm.h>
	17	#include <linux/delay.h>
	18
	19	#define SSD1307FB_WIDTH 96
	20	#define SSD1307FB_HEIGHT 16
	21
	22	#define SSD1307FB_DATA 0x40
	23	#define SSD1307FB_COMMAND 0x80
	24
	25	#define SSD1307FB_CONTRAST 0x81
	26	#define SSD1307FB_SEG_REMAP_ON 0xa1
	27	#define SSD1307FB_DISPLAY_OFF 0xae
	28	#define SSD1307FB_DISPLAY_ON 0xaf
	29	#define SSD1307FB_START_PAGE_ADDRESS 0xb0
	30
	31	struct ssd1307fb_par {
	32	struct i2c_client *client;
	33	struct fb_info *info;
	34	struct pwm_device *pwm;
	35	u32 pwm_period;
	36	int reset;
	37	};
	38
	39	static struct fb_fix_screeninfo ssd1307fb_fix __devinitdata = {
	40	.id = "Solomon SSD1307",
	41	.type = FB_TYPE_PACKED_PIXELS,
	42	.visual = FB_VISUAL_MONO10,
	43	.xpanstep = 0,
	44	.ypanstep = 0,
	45	.ywrapstep = 0,
	46	.line_length = SSD1307FB_WIDTH / 8,
	47	.accel = FB_ACCEL_NONE,
	48	};
	49
	50	static struct fb_var_screeninfo ssd1307fb_var __devinitdata = {
	51	.xres = SSD1307FB_WIDTH,
	52	.yres = SSD1307FB_HEIGHT,
	53	.xres_virtual = SSD1307FB_WIDTH,
	54	.yres_virtual = SSD1307FB_HEIGHT,
	55	.bits_per_pixel = 1,
	56	};
	57
	58	static int ssd1307fb_write_array(struct i2c_client client, u8 type, u8 cmd, u32 len)
	59	{
	60	u8 *buf;
	61	int ret = 0;
	62
	63	buf = kzalloc(len + 1, GFP_KERNEL);
	64	if (!buf) {
65	dev_err(&client->dev, "Couldn't allocate sending buffer.\n");
66	return -ENOMEM;
67	}
68
69	buf[0] = type;
70	memcpy(buf + 1, cmd, len);
71
72	ret = i2c_master_send(client, buf, len + 1);
73	if (ret != len + 1) {
74	dev_err(&client->dev, "Couldn't send I2C command.\n");
75	goto error;
76	}
77
78	error:
79	kfree(buf);
80	return ret;
81	}
82
83	static inline int ssd1307fb_write_cmd_array(struct i2c_client client, u8 cmd, u32 len)
84	{
85	return ssd1307fb_write_array(client, SSD1307FB_COMMAND, cmd, len);
86	}
87
88	static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
89	{
90	return ssd1307fb_write_cmd_array(client, &cmd, 1);
91	}
92
93	static inline int ssd1307fb_write_data_array(struct i2c_client client, u8 cmd, u32 len)
94	{
95	return ssd1307fb_write_array(client, SSD1307FB_DATA, cmd, len);
96	}
97
98	static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data)
99	{
100	return ssd1307fb_write_data_array(client, &data, 1);
101	}
102
103	static void ssd1307fb_update_display(struct ssd1307fb_par *par)
104	{
105	u8 *vmem = par->info->screen_base;
106	int i, j, k;
107
108	/*
109	* The screen is divided in pages, each having a height of 8
110	* pixels, and the width of the screen. When sending a byte of
111	* data to the controller, it gives the 8 bits for the current
112	* column. I.e, the first byte are the 8 bits of the first
113	* column, then the 8 bits for the second column, etc.
114	*
115	*
116	* Representation of the screen, assuming it is 5 bits
117	* wide. Each letter-number combination is a bit that controls
118	* one pixel.
119	*
120	* A0 A1 A2 A3 A4
121	* B0 B1 B2 B3 B4
122	* C0 C1 C2 C3 C4
123	* D0 D1 D2 D3 D4
124	* E0 E1 E2 E3 E4
125	* F0 F1 F2 F3 F4
126	* G0 G1 G2 G3 G4
127	* H0 H1 H2 H3 H4
128	*
129	* If you want to update this screen, you need to send 5 bytes:
130	* (1) A0 B0 C0 D0 E0 F0 G0 H0
131	* (2) A1 B1 C1 D1 E1 F1 G1 H1
132	* (3) A2 B2 C2 D2 E2 F2 G2 H2
133	* (4) A3 B3 C3 D3 E3 F3 G3 H3
134	* (5) A4 B4 C4 D4 E4 F4 G4 H4
135	*/
136
137	for (i = 0; i < (SSD1307FB_HEIGHT / 8); i++) {
138	ssd1307fb_write_cmd(par->client, SSD1307FB_START_PAGE_ADDRESS + (i + 1));
139	ssd1307fb_write_cmd(par->client, 0x00);
140	ssd1307fb_write_cmd(par->client, 0x10);
141
142	for (j = 0; j < SSD1307FB_WIDTH; j++) {
143	u8 buf = 0;
144	for (k = 0; k < 8; k++) {
145	u32 page_length = SSD1307FB_WIDTH * i;
146	u32 index = page_length + (SSD1307FB_WIDTH * k + j) / 8;
147	u8 byte = *(vmem + index);
148	u8 bit = byte & (1 << (7 - (j % 8)));
149	bit = bit >> (7 - (j % 8));
150	buf \|= bit << k;
151	}
152	ssd1307fb_write_data(par->client, buf);
153	}
154	}
155	}
156
157
158	static ssize_t ssd1307fb_write(struct fb_info info, const char __user buf,
159	size_t count, loff_t *ppos)
160	{
161	struct ssd1307fb_par *par = info->par;
162	unsigned long total_size;
163	unsigned long p = *ppos;
164	u8 __iomem *dst;
165
166	total_size = info->fix.smem_len;
167
168	if (p > total_size)
169	return -EINVAL;
170
171	if (count + p > total_size)
172	count = total_size - p;
173
174	if (!count)
175	return -EINVAL;
176
177	dst = (void __force *) (info->screen_base + p);
178
179	if (copy_from_user(dst, buf, count))
180	return -EFAULT;
181
182	ssd1307fb_update_display(par);
183
184	*ppos += count;
185
186	return count;
187	}
188
189	static void ssd1307fb_fillrect(struct fb_info info, const struct fb_fillrect rect)
190	{
191	struct ssd1307fb_par *par = info->par;
192	sys_fillrect(info, rect);
193	ssd1307fb_update_display(par);
194	}
195
196	static void ssd1307fb_copyarea(struct fb_info info, const struct fb_copyarea area)
197	{
198	struct ssd1307fb_par *par = info->par;
199	sys_copyarea(info, area);
200	ssd1307fb_update_display(par);
201	}
202
203	static void ssd1307fb_imageblit(struct fb_info info, const struct fb_image image)
204	{
205	struct ssd1307fb_par *par = info->par;
206	sys_imageblit(info, image);
207	ssd1307fb_update_display(par);
208	}
209
210	static struct fb_ops ssd1307fb_ops = {
211	.owner = THIS_MODULE,
212	.fb_read = fb_sys_read,
213	.fb_write = ssd1307fb_write,
214	.fb_fillrect = ssd1307fb_fillrect,
215	.fb_copyarea = ssd1307fb_copyarea,
216	.fb_imageblit = ssd1307fb_imageblit,
217	};
218
219	static void ssd1307fb_deferred_io(struct fb_info *info,
220	struct list_head *pagelist)
221	{
222	ssd1307fb_update_display(info->par);
223	}
224
225	static struct fb_deferred_io ssd1307fb_defio = {
226	.delay = HZ,
227	.deferred_io = ssd1307fb_deferred_io,
228	};
229
230	static int __devinit ssd1307fb_probe(struct i2c_client client, const struct i2c_device_id id)
231	{
232	struct fb_info *info;
233	u32 vmem_size = SSD1307FB_WIDTH * SSD1307FB_HEIGHT / 8;
234	struct ssd1307fb_par *par;
235	u8 *vmem;
236	int ret;
237
238	if (!client->dev.of_node) {
239	dev_err(&client->dev, "No device tree data found!\n");
240	return -EINVAL;
241	}
242
243	info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
244	if (!info) {
245	dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
246	return -ENOMEM;
247	}
248
249	vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
250	if (!vmem) {
251	dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
252	ret = -ENOMEM;
253	goto fb_alloc_error;
254	}
255
256	info->fbops = &ssd1307fb_ops;
257	info->fix = ssd1307fb_fix;
258	info->fbdefio = &ssd1307fb_defio;
259
260	info->var = ssd1307fb_var;
261	info->var.red.length = 1;
262	info->var.red.offset = 0;
263	info->var.green.length = 1;
264	info->var.green.offset = 0;
265	info->var.blue.length = 1;
266	info->var.blue.offset = 0;
267
268	info->screen_base = (u8 __force __iomem *)vmem;
269	info->fix.smem_start = (unsigned long)vmem;
270	info->fix.smem_len = vmem_size;
271
272	fb_deferred_io_init(info);
273
274	par = info->par;
275	par->info = info;
276	par->client = client;
277
278	par->reset = of_get_named_gpio(client->dev.of_node,
279	"reset-gpios", 0);
280	if (!gpio_is_valid(par->reset)) {
281	ret = -EINVAL;
282	goto reset_oled_error;
283	}
284
285	ret = devm_gpio_request_one(&client->dev, par->reset,
286	GPIOF_OUT_INIT_HIGH,
287	"oled-reset");
288	if (ret) {
289	dev_err(&client->dev,
290	"failed to request gpio %d: %d\n",
291	par->reset, ret);
292	goto reset_oled_error;
293	}
294
295	par->pwm = pwm_get(&client->dev, NULL);
296	if (IS_ERR(par->pwm)) {
297	dev_err(&client->dev, "Could not get PWM from device tree!\n");
298	ret = PTR_ERR(par->pwm);
299	goto pwm_error;
300	}
301
302	par->pwm_period = pwm_get_period(par->pwm);
303
304	dev_dbg(&client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period);
305
306	ret = register_framebuffer(info);
307	if (ret) {
308	dev_err(&client->dev, "Couldn't register the framebuffer\n");
309	goto fbreg_error;
310	}
311
312	i2c_set_clientdata(client, info);
313
314	/* Reset the screen */
315	gpio_set_value(par->reset, 0);
316	udelay(4);
317	gpio_set_value(par->reset, 1);
318	udelay(4);
319
320	/* Enable the PWM */
321	pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
322	pwm_enable(par->pwm);
323
324	/* Map column 127 of the OLED to segment 0 */
325	ret = ssd1307fb_write_cmd(client, SSD1307FB_SEG_REMAP_ON);
326	if (ret < 0) {
327	dev_err(&client->dev, "Couldn't remap the screen.\n");
328	goto remap_error;
329	}
330
331	/* Turn on the display */
332	ret = ssd1307fb_write_cmd(client, SSD1307FB_DISPLAY_ON);
333	if (ret < 0) {
334	dev_err(&client->dev, "Couldn't turn the display on.\n");
335	goto remap_error;
336	}
337
338	dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
339
340	return 0;
341
342	remap_error:
343	unregister_framebuffer(info);
344	pwm_disable(par->pwm);
345	fbreg_error:
346	pwm_put(par->pwm);
347	pwm_error:
348	reset_oled_error:
349	fb_deferred_io_cleanup(info);
350	fb_alloc_error:
351	framebuffer_release(info);
352	return ret;
353	}
354
355	static int __devexit ssd1307fb_remove(struct i2c_client *client)
356	{
357	struct fb_info *info = i2c_get_clientdata(client);
358	struct ssd1307fb_par *par = info->par;
359
360	unregister_framebuffer(info);
361	pwm_disable(par->pwm);
362	pwm_put(par->pwm);
363	fb_deferred_io_cleanup(info);
364	framebuffer_release(info);
365
366	return 0;
367	}
368
369	static const struct i2c_device_id ssd1307fb_i2c_id[] = {
370	{ "ssd1307fb", 0 },
371	{ }
372	};
373	MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
374
375	static const struct of_device_id ssd1307fb_of_match[] = {
376	{ .compatible = "solomon,ssd1307fb-i2c" },
377	{},
378	};
379	MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
380
381	static struct i2c_driver ssd1307fb_driver = {
382	.probe = ssd1307fb_probe,
383	.remove = __devexit_p(ssd1307fb_remove),
384	.id_table = ssd1307fb_i2c_id,
385	.driver = {
386	.name = "ssd1307fb",
387	.of_match_table = of_match_ptr(ssd1307fb_of_match),
388	.owner = THIS_MODULE,
389	},
390	};
391
392	module_i2c_driver(ssd1307fb_driver);
393
394	MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controler");
395	MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
396	MODULE_LICENSE("GPL");