Root/drivers/regulator/max8660.c

1/*
2 * max8660.c -- Voltage regulation for the Maxim 8660/8661
3 *
4 * based on max1586.c and wm8400-regulator.c
5 *
6 * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
19 * Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 * Some info:
22 *
23 * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf
24 *
25 * This chip is a bit nasty because it is a write-only device. Thus, the driver
26 * uses shadow registers to keep track of its values. The main problem appears
27 * to be the initialization: When Linux boots up, we cannot know if the chip is
28 * in the default state or not, so we would have to pass such information in
29 * platform_data. As this adds a bit of complexity to the driver, this is left
30 * out for now until it is really needed.
31 *
32 * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2.
33 *
34 * If the driver is feature complete, it might be worth to check if one set of
35 * functions for V3-V7 is sufficient. For maximum flexibility during
36 * development, they are separated for now.
37 *
38 */
39
40#include <linux/module.h>
41#include <linux/err.h>
42#include <linux/i2c.h>
43#include <linux/platform_device.h>
44#include <linux/regulator/driver.h>
45#include <linux/slab.h>
46#include <linux/regulator/max8660.h>
47
48#define MAX8660_DCDC_MIN_UV 725000
49#define MAX8660_DCDC_MAX_UV 1800000
50#define MAX8660_DCDC_STEP 25000
51#define MAX8660_DCDC_MAX_SEL 0x2b
52
53#define MAX8660_LDO5_MIN_UV 1700000
54#define MAX8660_LDO5_MAX_UV 2000000
55#define MAX8660_LDO5_STEP 25000
56#define MAX8660_LDO5_MAX_SEL 0x0c
57
58#define MAX8660_LDO67_MIN_UV 1800000
59#define MAX8660_LDO67_MAX_UV 3300000
60#define MAX8660_LDO67_STEP 100000
61#define MAX8660_LDO67_MAX_SEL 0x0f
62
63enum {
64    MAX8660_OVER1,
65    MAX8660_OVER2,
66    MAX8660_VCC1,
67    MAX8660_ADTV1,
68    MAX8660_ADTV2,
69    MAX8660_SDTV1,
70    MAX8660_SDTV2,
71    MAX8660_MDTV1,
72    MAX8660_MDTV2,
73    MAX8660_L12VCR,
74    MAX8660_FPWM,
75    MAX8660_N_REGS, /* not a real register */
76};
77
78struct max8660 {
79    struct i2c_client *client;
80    u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */
81    struct regulator_dev *rdev[];
82};
83
84static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
85{
86    static const u8 max8660_addresses[MAX8660_N_REGS] =
87      { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 };
88
89    int ret;
90    u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
91    dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
92            max8660_addresses[reg], reg_val);
93
94    ret = i2c_smbus_write_byte_data(max8660->client,
95            max8660_addresses[reg], reg_val);
96    if (ret == 0)
97        max8660->shadow_regs[reg] = reg_val;
98
99    return ret;
100}
101
102
103/*
104 * DCDC functions
105 */
106
107static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
108{
109    struct max8660 *max8660 = rdev_get_drvdata(rdev);
110    u8 val = max8660->shadow_regs[MAX8660_OVER1];
111    u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
112    return !!(val & mask);
113}
114
115static int max8660_dcdc_enable(struct regulator_dev *rdev)
116{
117    struct max8660 *max8660 = rdev_get_drvdata(rdev);
118    u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
119    return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
120}
121
122static int max8660_dcdc_disable(struct regulator_dev *rdev)
123{
124    struct max8660 *max8660 = rdev_get_drvdata(rdev);
125    u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
126    return max8660_write(max8660, MAX8660_OVER1, mask, 0);
127}
128
129static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev)
130{
131    struct max8660 *max8660 = rdev_get_drvdata(rdev);
132
133    u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
134    u8 selector = max8660->shadow_regs[reg];
135    return selector;
136}
137
138static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
139                    unsigned int selector)
140{
141    struct max8660 *max8660 = rdev_get_drvdata(rdev);
142    u8 reg, bits;
143    int ret;
144
145    reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
146    ret = max8660_write(max8660, reg, 0, selector);
147    if (ret)
148        return ret;
149
150    /* Select target voltage register and activate regulation */
151    bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
152    return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
153}
154
155static struct regulator_ops max8660_dcdc_ops = {
156    .is_enabled = max8660_dcdc_is_enabled,
157    .list_voltage = regulator_list_voltage_linear,
158    .map_voltage = regulator_map_voltage_linear,
159    .set_voltage_sel = max8660_dcdc_set_voltage_sel,
160    .get_voltage_sel = max8660_dcdc_get_voltage_sel,
161};
162
163
164/*
165 * LDO5 functions
166 */
167
168static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
169{
170    struct max8660 *max8660 = rdev_get_drvdata(rdev);
171
172    u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
173    return selector;
174}
175
176static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
177                    unsigned int selector)
178{
179    struct max8660 *max8660 = rdev_get_drvdata(rdev);
180    int ret;
181
182    ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
183    if (ret)
184        return ret;
185
186    /* Select target voltage register and activate regulation */
187    return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
188}
189
190static struct regulator_ops max8660_ldo5_ops = {
191    .list_voltage = regulator_list_voltage_linear,
192    .map_voltage = regulator_map_voltage_linear,
193    .set_voltage_sel = max8660_ldo5_set_voltage_sel,
194    .get_voltage_sel = max8660_ldo5_get_voltage_sel,
195};
196
197
198/*
199 * LDO67 functions
200 */
201
202static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
203{
204    struct max8660 *max8660 = rdev_get_drvdata(rdev);
205    u8 val = max8660->shadow_regs[MAX8660_OVER2];
206    u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
207    return !!(val & mask);
208}
209
210static int max8660_ldo67_enable(struct regulator_dev *rdev)
211{
212    struct max8660 *max8660 = rdev_get_drvdata(rdev);
213    u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
214    return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
215}
216
217static int max8660_ldo67_disable(struct regulator_dev *rdev)
218{
219    struct max8660 *max8660 = rdev_get_drvdata(rdev);
220    u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
221    return max8660_write(max8660, MAX8660_OVER2, mask, 0);
222}
223
224static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
225{
226    struct max8660 *max8660 = rdev_get_drvdata(rdev);
227
228    u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
229    u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
230    return selector;
231}
232
233static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
234                     unsigned int selector)
235{
236    struct max8660 *max8660 = rdev_get_drvdata(rdev);
237
238    if (rdev_get_id(rdev) == MAX8660_V6)
239        return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
240    else
241        return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
242                     selector << 4);
243}
244
245static struct regulator_ops max8660_ldo67_ops = {
246    .is_enabled = max8660_ldo67_is_enabled,
247    .enable = max8660_ldo67_enable,
248    .disable = max8660_ldo67_disable,
249    .list_voltage = regulator_list_voltage_linear,
250    .map_voltage = regulator_map_voltage_linear,
251    .get_voltage_sel = max8660_ldo67_get_voltage_sel,
252    .set_voltage_sel = max8660_ldo67_set_voltage_sel,
253};
254
255static const struct regulator_desc max8660_reg[] = {
256    {
257        .name = "V3(DCDC)",
258        .id = MAX8660_V3,
259        .ops = &max8660_dcdc_ops,
260        .type = REGULATOR_VOLTAGE,
261        .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
262        .owner = THIS_MODULE,
263        .min_uV = MAX8660_DCDC_MIN_UV,
264        .uV_step = MAX8660_DCDC_STEP,
265    },
266    {
267        .name = "V4(DCDC)",
268        .id = MAX8660_V4,
269        .ops = &max8660_dcdc_ops,
270        .type = REGULATOR_VOLTAGE,
271        .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
272        .owner = THIS_MODULE,
273        .min_uV = MAX8660_DCDC_MIN_UV,
274        .uV_step = MAX8660_DCDC_STEP,
275    },
276    {
277        .name = "V5(LDO)",
278        .id = MAX8660_V5,
279        .ops = &max8660_ldo5_ops,
280        .type = REGULATOR_VOLTAGE,
281        .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
282        .owner = THIS_MODULE,
283        .min_uV = MAX8660_LDO5_MIN_UV,
284        .uV_step = MAX8660_LDO5_STEP,
285    },
286    {
287        .name = "V6(LDO)",
288        .id = MAX8660_V6,
289        .ops = &max8660_ldo67_ops,
290        .type = REGULATOR_VOLTAGE,
291        .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
292        .owner = THIS_MODULE,
293        .min_uV = MAX8660_LDO67_MIN_UV,
294        .uV_step = MAX8660_LDO67_STEP,
295    },
296    {
297        .name = "V7(LDO)",
298        .id = MAX8660_V7,
299        .ops = &max8660_ldo67_ops,
300        .type = REGULATOR_VOLTAGE,
301        .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
302        .owner = THIS_MODULE,
303        .min_uV = MAX8660_LDO67_MIN_UV,
304        .uV_step = MAX8660_LDO67_STEP,
305    },
306};
307
308static int __devinit max8660_probe(struct i2c_client *client,
309                   const struct i2c_device_id *i2c_id)
310{
311    struct regulator_dev **rdev;
312    struct max8660_platform_data *pdata = client->dev.platform_data;
313    struct regulator_config config = { };
314    struct max8660 *max8660;
315    int boot_on, i, id, ret = -EINVAL;
316
317    if (pdata->num_subdevs > MAX8660_V_END) {
318        dev_err(&client->dev, "Too many regulators found!\n");
319        return -EINVAL;
320    }
321
322    max8660 = devm_kzalloc(&client->dev, sizeof(struct max8660) +
323            sizeof(struct regulator_dev *) * MAX8660_V_END,
324            GFP_KERNEL);
325    if (!max8660)
326        return -ENOMEM;
327
328    max8660->client = client;
329    rdev = max8660->rdev;
330
331    if (pdata->en34_is_high) {
332        /* Simulate always on */
333        max8660->shadow_regs[MAX8660_OVER1] = 5;
334    } else {
335        /* Otherwise devices can be toggled via software */
336        max8660_dcdc_ops.enable = max8660_dcdc_enable;
337        max8660_dcdc_ops.disable = max8660_dcdc_disable;
338    }
339
340    /*
341     * First, set up shadow registers to prevent glitches. As some
342     * registers are shared between regulators, everything must be properly
343     * set up for all regulators in advance.
344     */
345    max8660->shadow_regs[MAX8660_ADTV1] =
346        max8660->shadow_regs[MAX8660_ADTV2] =
347        max8660->shadow_regs[MAX8660_SDTV1] =
348        max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
349    max8660->shadow_regs[MAX8660_MDTV1] =
350        max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
351
352    for (i = 0; i < pdata->num_subdevs; i++) {
353
354        if (!pdata->subdevs[i].platform_data)
355            goto err_out;
356
357        boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
358
359        switch (pdata->subdevs[i].id) {
360        case MAX8660_V3:
361            if (boot_on)
362                max8660->shadow_regs[MAX8660_OVER1] |= 1;
363            break;
364
365        case MAX8660_V4:
366            if (boot_on)
367                max8660->shadow_regs[MAX8660_OVER1] |= 4;
368            break;
369
370        case MAX8660_V5:
371            break;
372
373        case MAX8660_V6:
374            if (boot_on)
375                max8660->shadow_regs[MAX8660_OVER2] |= 2;
376            break;
377
378        case MAX8660_V7:
379            if (!strcmp(i2c_id->name, "max8661")) {
380                dev_err(&client->dev, "Regulator not on this chip!\n");
381                goto err_out;
382            }
383
384            if (boot_on)
385                max8660->shadow_regs[MAX8660_OVER2] |= 4;
386            break;
387
388        default:
389            dev_err(&client->dev, "invalid regulator %s\n",
390                 pdata->subdevs[i].name);
391            goto err_out;
392        }
393    }
394
395    /* Finally register devices */
396    for (i = 0; i < pdata->num_subdevs; i++) {
397
398        id = pdata->subdevs[i].id;
399
400        config.dev = &client->dev;
401        config.init_data = pdata->subdevs[i].platform_data;
402        config.driver_data = max8660;
403
404        rdev[i] = regulator_register(&max8660_reg[id], &config);
405        if (IS_ERR(rdev[i])) {
406            ret = PTR_ERR(rdev[i]);
407            dev_err(&client->dev, "failed to register %s\n",
408                max8660_reg[id].name);
409            goto err_unregister;
410        }
411    }
412
413    i2c_set_clientdata(client, max8660);
414    return 0;
415
416err_unregister:
417    while (--i >= 0)
418        regulator_unregister(rdev[i]);
419err_out:
420    return ret;
421}
422
423static int __devexit max8660_remove(struct i2c_client *client)
424{
425    struct max8660 *max8660 = i2c_get_clientdata(client);
426    int i;
427
428    for (i = 0; i < MAX8660_V_END; i++)
429        if (max8660->rdev[i])
430            regulator_unregister(max8660->rdev[i]);
431    return 0;
432}
433
434static const struct i2c_device_id max8660_id[] = {
435    { "max8660", 0 },
436    { "max8661", 0 },
437    { }
438};
439MODULE_DEVICE_TABLE(i2c, max8660_id);
440
441static struct i2c_driver max8660_driver = {
442    .probe = max8660_probe,
443    .remove = __devexit_p(max8660_remove),
444    .driver = {
445        .name = "max8660",
446        .owner = THIS_MODULE,
447    },
448    .id_table = max8660_id,
449};
450
451static int __init max8660_init(void)
452{
453    return i2c_add_driver(&max8660_driver);
454}
455subsys_initcall(max8660_init);
456
457static void __exit max8660_exit(void)
458{
459    i2c_del_driver(&max8660_driver);
460}
461module_exit(max8660_exit);
462
463/* Module information */
464MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
465MODULE_AUTHOR("Wolfram Sang");
466MODULE_LICENSE("GPL v2");
467

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