blob: dec790de72ff4a8496c28be145c834353e06cebc [file] [log] [blame]
Olimpiu Dejeue739c5b2017-03-21 12:58:48 -04001/*
2 * Backlight driver for ArcticSand ARC_X_C_0N_0N Devices
3 *
4 * Copyright 2016 ArcticSand, Inc.
5 * Author : Brian Dodge <bdodge@arcticsand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/backlight.h>
21#include <linux/err.h>
22#include <linux/i2c.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/slab.h>
26
27enum arcxcnn_chip_id {
28 ARC2C0608
29};
30
31/**
32 * struct arcxcnn_platform_data
33 * @name : Backlight driver name (NULL will use default)
34 * @initial_brightness : initial value of backlight brightness
35 * @leden : initial LED string enables, upper bit is global on/off
36 * @led_config_0 : fading speed (period between intensity steps)
37 * @led_config_1 : misc settings, see datasheet
38 * @dim_freq : pwm dimming frequency if in pwm mode
39 * @comp_config : misc config, see datasheet
40 * @filter_config : RC/PWM filter config, see datasheet
41 * @trim_config : full scale current trim, see datasheet
42 */
43struct arcxcnn_platform_data {
44 const char *name;
45 u16 initial_brightness;
46 u8 leden;
47 u8 led_config_0;
48 u8 led_config_1;
49 u8 dim_freq;
50 u8 comp_config;
51 u8 filter_config;
52 u8 trim_config;
53};
54
55#define ARCXCNN_CMD 0x00 /* Command Register */
56#define ARCXCNN_CMD_STDBY 0x80 /* I2C Standby */
57#define ARCXCNN_CMD_RESET 0x40 /* Reset */
58#define ARCXCNN_CMD_BOOST 0x10 /* Boost */
59#define ARCXCNN_CMD_OVP_MASK 0x0C /* --- Over Voltage Threshold */
60#define ARCXCNN_CMD_OVP_XXV 0x0C /* <rsvrd> Over Voltage Threshold */
61#define ARCXCNN_CMD_OVP_20V 0x08 /* 20v Over Voltage Threshold */
62#define ARCXCNN_CMD_OVP_24V 0x04 /* 24v Over Voltage Threshold */
63#define ARCXCNN_CMD_OVP_31V 0x00 /* 31.4v Over Voltage Threshold */
64#define ARCXCNN_CMD_EXT_COMP 0x01 /* part (0) or full (1) ext. comp */
65
66#define ARCXCNN_CONFIG 0x01 /* Configuration */
67#define ARCXCNN_STATUS1 0x02 /* Status 1 */
68#define ARCXCNN_STATUS2 0x03 /* Status 2 */
69#define ARCXCNN_FADECTRL 0x04 /* Fading Control */
70#define ARCXCNN_ILED_CONFIG 0x05 /* ILED Configuration */
71#define ARCXCNN_ILED_DIM_PWM 0x00 /* config dim mode pwm */
72#define ARCXCNN_ILED_DIM_INT 0x04 /* config dim mode internal */
73#define ARCXCNN_LEDEN 0x06 /* LED Enable Register */
74#define ARCXCNN_LEDEN_ISETEXT 0x80 /* Full-scale current set extern */
75#define ARCXCNN_LEDEN_MASK 0x3F /* LED string enables mask */
76#define ARCXCNN_LEDEN_BITS 0x06 /* Bits of LED string enables */
77#define ARCXCNN_LEDEN_LED1 0x01
78#define ARCXCNN_LEDEN_LED2 0x02
79#define ARCXCNN_LEDEN_LED3 0x04
80#define ARCXCNN_LEDEN_LED4 0x08
81#define ARCXCNN_LEDEN_LED5 0x10
82#define ARCXCNN_LEDEN_LED6 0x20
83
84#define ARCXCNN_WLED_ISET_LSB 0x07 /* LED ISET LSB (in upper nibble) */
85#define ARCXCNN_WLED_ISET_LSB_SHIFT 0x04 /* ISET LSB Left Shift */
86#define ARCXCNN_WLED_ISET_MSB 0x08 /* LED ISET MSB (8 bits) */
87
88#define ARCXCNN_DIMFREQ 0x09
89#define ARCXCNN_COMP_CONFIG 0x0A
90#define ARCXCNN_FILT_CONFIG 0x0B
91#define ARCXCNN_IMAXTUNE 0x0C
92#define ARCXCNN_ID_MSB 0x1E
93#define ARCXCNN_ID_LSB 0x1F
94
95#define MAX_BRIGHTNESS 4095
96#define INIT_BRIGHT 60
97
98struct arcxcnn {
99 struct i2c_client *client;
100 struct backlight_device *bl;
101 struct device *dev;
102 struct arcxcnn_platform_data *pdata;
103};
104
105static int arcxcnn_update_field(struct arcxcnn *lp, u8 reg, u8 mask, u8 data)
106{
107 int ret;
108 u8 tmp;
109
110 ret = i2c_smbus_read_byte_data(lp->client, reg);
111 if (ret < 0) {
112 dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
113 return ret;
114 }
115
116 tmp = (u8)ret;
117 tmp &= ~mask;
118 tmp |= data & mask;
119
120 return i2c_smbus_write_byte_data(lp->client, reg, tmp);
121}
122
123static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness)
124{
125 int ret;
126 u8 val;
127
128 /* lower nibble of brightness goes in upper nibble of LSB register */
129 val = (brightness & 0xF) << ARCXCNN_WLED_ISET_LSB_SHIFT;
130 ret = i2c_smbus_write_byte_data(lp->client,
131 ARCXCNN_WLED_ISET_LSB, val);
132 if (ret < 0)
133 return ret;
134
135 /* remaining 8 bits of brightness go in MSB register */
136 val = (brightness >> 4);
137 return i2c_smbus_write_byte_data(lp->client,
138 ARCXCNN_WLED_ISET_MSB, val);
139}
140
141static int arcxcnn_bl_update_status(struct backlight_device *bl)
142{
143 struct arcxcnn *lp = bl_get_data(bl);
144 u32 brightness = bl->props.brightness;
145 int ret;
146
147 if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
148 brightness = 0;
149
150 ret = arcxcnn_set_brightness(lp, brightness);
151 if (ret)
152 return ret;
153
154 /* set power-on/off/save modes */
155 return arcxcnn_update_field(lp, ARCXCNN_CMD, ARCXCNN_CMD_STDBY,
156 (bl->props.power == 0) ? 0 : ARCXCNN_CMD_STDBY);
157}
158
159static const struct backlight_ops arcxcnn_bl_ops = {
160 .options = BL_CORE_SUSPENDRESUME,
161 .update_status = arcxcnn_bl_update_status,
162};
163
164static int arcxcnn_backlight_register(struct arcxcnn *lp)
165{
166 struct backlight_properties *props;
167 const char *name = lp->pdata->name ? : "arctic_bl";
168
169 props = devm_kzalloc(lp->dev, sizeof(*props), GFP_KERNEL);
170 if (!props)
171 return -ENOMEM;
172
173 props->type = BACKLIGHT_PLATFORM;
174 props->max_brightness = MAX_BRIGHTNESS;
175
176 if (lp->pdata->initial_brightness > props->max_brightness)
177 lp->pdata->initial_brightness = props->max_brightness;
178
179 props->brightness = lp->pdata->initial_brightness;
180
181 lp->bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
182 &arcxcnn_bl_ops, props);
183 return PTR_ERR_OR_ZERO(lp->bl);
184}
185
186static void arcxcnn_parse_dt(struct arcxcnn *lp)
187{
188 struct device *dev = lp->dev;
189 struct device_node *node = dev->of_node;
190 u32 prog_val, num_entry, entry, sources[ARCXCNN_LEDEN_BITS];
191 int ret;
192
193 /* device tree entry isn't required, defaults are OK */
194 if (!node)
195 return;
196
197 ret = of_property_read_string(node, "label", &lp->pdata->name);
198 if (ret < 0)
199 lp->pdata->name = NULL;
200
201 ret = of_property_read_u32(node, "default-brightness", &prog_val);
202 if (ret == 0)
203 lp->pdata->initial_brightness = prog_val;
204
205 ret = of_property_read_u32(node, "arc,led-config-0", &prog_val);
206 if (ret == 0)
207 lp->pdata->led_config_0 = (u8)prog_val;
208
209 ret = of_property_read_u32(node, "arc,led-config-1", &prog_val);
210 if (ret == 0)
211 lp->pdata->led_config_1 = (u8)prog_val;
212
213 ret = of_property_read_u32(node, "arc,dim-freq", &prog_val);
214 if (ret == 0)
215 lp->pdata->dim_freq = (u8)prog_val;
216
217 ret = of_property_read_u32(node, "arc,comp-config", &prog_val);
218 if (ret == 0)
219 lp->pdata->comp_config = (u8)prog_val;
220
221 ret = of_property_read_u32(node, "arc,filter-config", &prog_val);
222 if (ret == 0)
223 lp->pdata->filter_config = (u8)prog_val;
224
225 ret = of_property_read_u32(node, "arc,trim-config", &prog_val);
226 if (ret == 0)
227 lp->pdata->trim_config = (u8)prog_val;
228
229 ret = of_property_count_u32_elems(node, "led-sources");
230 if (ret < 0) {
231 lp->pdata->leden = ARCXCNN_LEDEN_MASK; /* all on is default */
232 } else {
233 num_entry = ret;
234 if (num_entry > ARCXCNN_LEDEN_BITS)
235 num_entry = ARCXCNN_LEDEN_BITS;
236
237 ret = of_property_read_u32_array(node, "led-sources", sources,
238 num_entry);
239 if (ret < 0) {
240 dev_err(dev, "led-sources node is invalid.\n");
241 return;
242 }
243
244 lp->pdata->leden = 0;
245
246 /* for each enable in source, set bit in led enable */
247 for (entry = 0; entry < num_entry; entry++) {
248 u8 onbit = 1 << sources[entry];
249
250 lp->pdata->leden |= onbit;
251 }
252 }
253}
254
255static int arcxcnn_probe(struct i2c_client *cl, const struct i2c_device_id *id)
256{
257 struct arcxcnn *lp;
258 int ret;
259
260 if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
261 return -EIO;
262
263 lp = devm_kzalloc(&cl->dev, sizeof(*lp), GFP_KERNEL);
264 if (!lp)
265 return -ENOMEM;
266
267 lp->client = cl;
268 lp->dev = &cl->dev;
269 lp->pdata = dev_get_platdata(&cl->dev);
270
271 /* reset the device */
272 ret = i2c_smbus_write_byte_data(lp->client,
273 ARCXCNN_CMD, ARCXCNN_CMD_RESET);
274 if (ret)
275 goto probe_err;
276
277 if (!lp->pdata) {
278 lp->pdata = devm_kzalloc(lp->dev,
279 sizeof(*lp->pdata), GFP_KERNEL);
280 if (!lp->pdata)
281 return -ENOMEM;
282
283 /* Setup defaults based on power-on defaults */
284 lp->pdata->name = NULL;
285 lp->pdata->initial_brightness = INIT_BRIGHT;
286 lp->pdata->leden = ARCXCNN_LEDEN_MASK;
287
288 lp->pdata->led_config_0 = i2c_smbus_read_byte_data(
289 lp->client, ARCXCNN_FADECTRL);
290
291 lp->pdata->led_config_1 = i2c_smbus_read_byte_data(
292 lp->client, ARCXCNN_ILED_CONFIG);
293 /* insure dim mode is not default pwm */
294 lp->pdata->led_config_1 |= ARCXCNN_ILED_DIM_INT;
295
296 lp->pdata->dim_freq = i2c_smbus_read_byte_data(
297 lp->client, ARCXCNN_DIMFREQ);
298
299 lp->pdata->comp_config = i2c_smbus_read_byte_data(
300 lp->client, ARCXCNN_COMP_CONFIG);
301
302 lp->pdata->filter_config = i2c_smbus_read_byte_data(
303 lp->client, ARCXCNN_FILT_CONFIG);
304
305 lp->pdata->trim_config = i2c_smbus_read_byte_data(
306 lp->client, ARCXCNN_IMAXTUNE);
307
308 if (IS_ENABLED(CONFIG_OF))
309 arcxcnn_parse_dt(lp);
310 }
311
312 i2c_set_clientdata(cl, lp);
313
314 /* constrain settings to what is possible */
315 if (lp->pdata->initial_brightness > MAX_BRIGHTNESS)
316 lp->pdata->initial_brightness = MAX_BRIGHTNESS;
317
318 /* set initial brightness */
319 ret = arcxcnn_set_brightness(lp, lp->pdata->initial_brightness);
320 if (ret)
321 goto probe_err;
322
323 /* set other register values directly */
324 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FADECTRL,
325 lp->pdata->led_config_0);
326 if (ret)
327 goto probe_err;
328
329 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_ILED_CONFIG,
330 lp->pdata->led_config_1);
331 if (ret)
332 goto probe_err;
333
334 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_DIMFREQ,
335 lp->pdata->dim_freq);
336 if (ret)
337 goto probe_err;
338
339 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_COMP_CONFIG,
340 lp->pdata->comp_config);
341 if (ret)
342 goto probe_err;
343
344 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FILT_CONFIG,
345 lp->pdata->filter_config);
346 if (ret)
347 goto probe_err;
348
349 ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_IMAXTUNE,
350 lp->pdata->trim_config);
351 if (ret)
352 goto probe_err;
353
354 /* set initial LED Enables */
355 arcxcnn_update_field(lp, ARCXCNN_LEDEN,
356 ARCXCNN_LEDEN_MASK, lp->pdata->leden);
357
358 ret = arcxcnn_backlight_register(lp);
359 if (ret)
360 goto probe_register_err;
361
362 backlight_update_status(lp->bl);
363
364 return 0;
365
366probe_register_err:
367 dev_err(lp->dev,
368 "failed to register backlight.\n");
369
370probe_err:
371 dev_err(lp->dev,
372 "failure ret: %d\n", ret);
373 return ret;
374}
375
376static int arcxcnn_remove(struct i2c_client *cl)
377{
378 struct arcxcnn *lp = i2c_get_clientdata(cl);
379
380 /* disable all strings (ignore errors) */
381 i2c_smbus_write_byte_data(lp->client,
382 ARCXCNN_LEDEN, 0x00);
383 /* reset the device (ignore errors) */
384 i2c_smbus_write_byte_data(lp->client,
385 ARCXCNN_CMD, ARCXCNN_CMD_RESET);
386
387 lp->bl->props.brightness = 0;
388
389 backlight_update_status(lp->bl);
390
391 return 0;
392}
393
394static const struct of_device_id arcxcnn_dt_ids[] = {
395 { .compatible = "arc,arc2c0608" },
396 { }
397};
398MODULE_DEVICE_TABLE(of, arcxcnn_dt_ids);
399
400static const struct i2c_device_id arcxcnn_ids[] = {
401 {"arc2c0608", ARC2C0608},
402 { }
403};
404MODULE_DEVICE_TABLE(i2c, arcxcnn_ids);
405
406static struct i2c_driver arcxcnn_driver = {
407 .driver = {
408 .name = "arcxcnn_bl",
409 .of_match_table = of_match_ptr(arcxcnn_dt_ids),
410 },
411 .probe = arcxcnn_probe,
412 .remove = arcxcnn_remove,
413 .id_table = arcxcnn_ids,
414};
415module_i2c_driver(arcxcnn_driver);
416
417MODULE_LICENSE("GPL v2");
418MODULE_AUTHOR("Brian Dodge <bdodge@arcticsand.com>");
419MODULE_DESCRIPTION("ARCXCNN Backlight driver");