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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed
0004  *        PWM controller chips from G762 family, i.e. G762 and G763
0005  *
0006  * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
0007  *
0008  * This work is based on a basic version for 2.6.31 kernel developed
0009  * by Olivier Mouchet for LaCie. Updates and correction have been
0010  * performed to run on recent kernels. Additional features, like the
0011  * ability to configure various characteristics via .dts file or
0012  * board init file have been added. Detailed datasheet on which this
0013  * development is based is available here:
0014  *
0015  *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
0016  *
0017  * Headers from previous developments have been kept below:
0018  *
0019  * Copyright (c) 2009 LaCie
0020  *
0021  * Author: Olivier Mouchet <olivier.mouchet@gmail.com>
0022  *
0023  * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org>
0024  * Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>
0025  *
0026  * g762: minimal datasheet available at:
0027  *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
0028  */
0029 
0030 #include <linux/device.h>
0031 #include <linux/module.h>
0032 #include <linux/init.h>
0033 #include <linux/jiffies.h>
0034 #include <linux/i2c.h>
0035 #include <linux/hwmon.h>
0036 #include <linux/hwmon-sysfs.h>
0037 #include <linux/err.h>
0038 #include <linux/mutex.h>
0039 #include <linux/kernel.h>
0040 #include <linux/clk.h>
0041 #include <linux/of.h>
0042 #include <linux/of_device.h>
0043 #include <linux/platform_data/g762.h>
0044 
0045 #define DRVNAME "g762"
0046 
0047 static const struct i2c_device_id g762_id[] = {
0048     { "g762", 0 },
0049     { "g763", 0 },
0050     { }
0051 };
0052 MODULE_DEVICE_TABLE(i2c, g762_id);
0053 
0054 enum g762_regs {
0055     G762_REG_SET_CNT  = 0x00,
0056     G762_REG_ACT_CNT  = 0x01,
0057     G762_REG_FAN_STA  = 0x02,
0058     G762_REG_SET_OUT  = 0x03,
0059     G762_REG_FAN_CMD1 = 0x04,
0060     G762_REG_FAN_CMD2 = 0x05,
0061 };
0062 
0063 /* Config register bits */
0064 #define G762_REG_FAN_CMD1_DET_FAN_FAIL  0x80 /* enable fan_fail signal */
0065 #define G762_REG_FAN_CMD1_DET_FAN_OOC   0x40 /* enable fan_out_of_control */
0066 #define G762_REG_FAN_CMD1_OUT_MODE      0x20 /* out mode: PWM or DC */
0067 #define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: closed/open-loop */
0068 #define G762_REG_FAN_CMD1_CLK_DIV_ID1   0x08 /* clock divisor value */
0069 #define G762_REG_FAN_CMD1_CLK_DIV_ID0   0x04
0070 #define G762_REG_FAN_CMD1_PWM_POLARITY  0x02 /* PWM polarity */
0071 #define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
0072 
0073 #define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
0074 #define G762_REG_FAN_CMD2_GEAR_MODE_0   0x04
0075 #define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
0076 #define G762_REG_FAN_CMD2_FAN_STARTV_0  0x01
0077 
0078 #define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
0079 #define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
0080 
0081 /* Config register values */
0082 #define G762_OUT_MODE_PWM            1
0083 #define G762_OUT_MODE_DC             0
0084 
0085 #define G762_FAN_MODE_CLOSED_LOOP    2
0086 #define G762_FAN_MODE_OPEN_LOOP      1
0087 
0088 #define G762_PWM_POLARITY_NEGATIVE   1
0089 #define G762_PWM_POLARITY_POSITIVE   0
0090 
0091 /* Register data is read (and cached) at most once per second. */
0092 #define G762_UPDATE_INTERVAL    HZ
0093 
0094 /*
0095  * Extract pulse count per fan revolution value (2 or 4) from given
0096  * FAN_CMD1 register value.
0097  */
0098 #define G762_PULSE_FROM_REG(reg) \
0099     ((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1)
0100 
0101 /*
0102  * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
0103  * register value.
0104  */
0105 #define G762_CLKDIV_FROM_REG(reg) \
0106     (1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 |    \
0107              G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2))
0108 
0109 /*
0110  * Extract fan gear mode multiplier value (0, 2 or 4) from given
0111  * FAN_CMD2 register value.
0112  */
0113 #define G762_GEARMULT_FROM_REG(reg) \
0114     (1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 |    \
0115              G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))
0116 
0117 struct g762_data {
0118     struct i2c_client *client;
0119     struct clk *clk;
0120 
0121     /* update mutex */
0122     struct mutex update_lock;
0123 
0124     /* board specific parameters. */
0125     u32 clk_freq;
0126 
0127     /* g762 register cache */
0128     bool valid;
0129     unsigned long last_updated; /* in jiffies */
0130 
0131     u8 set_cnt;  /* controls fan rotation speed in closed-loop mode */
0132     u8 act_cnt;  /* provides access to current fan RPM value */
0133     u8 fan_sta;  /* bit 0: set when actual fan speed is more than
0134               *        25% outside requested fan speed
0135               * bit 1: set when no transition occurs on fan
0136               *        pin for 0.7s
0137               */
0138     u8 set_out;  /* controls fan rotation speed in open-loop mode */
0139     u8 fan_cmd1; /*   0: FG_PLS_ID0 FG pulses count per revolution
0140               *      0: 2 counts per revolution
0141               *      1: 4 counts per revolution
0142               *   1: PWM_POLARITY 1: negative_duty
0143               *                   0: positive_duty
0144               * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1]
0145               *         00: Divide fan clock by 1
0146               *         01: Divide fan clock by 2
0147               *         10: Divide fan clock by 4
0148               *         11: Divide fan clock by 8
0149               *   4: FAN_MODE 1:closed-loop, 0:open-loop
0150               *   5: OUT_MODE 1:PWM, 0:DC
0151               *   6: DET_FAN_OOC enable "fan ooc" status
0152               *   7: DET_FAN_FAIL enable "fan fail" status
0153               */
0154     u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
0155               * 2,3: FG_GEAR_MODE
0156               *         00: multiplier = 1
0157               *         01: multiplier = 2
0158               *         10: multiplier = 4
0159               *   4: Mask ALERT# (g763 only)
0160               */
0161 };
0162 
0163 /*
0164  * Convert count value from fan controller register (FAN_SET_CNT) into fan
0165  * speed RPM value. Note that the datasheet documents a basic formula;
0166  * influence of additional parameters (fan clock divisor, fan gear mode)
0167  * have been infered from examples in the datasheet and tests.
0168  */
0169 static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p,
0170                     u8 clk_div, u8 gear_mult)
0171 {
0172     if (cnt == 0xff)  /* setting cnt to 255 stops the fan */
0173         return 0;
0174 
0175     return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div);
0176 }
0177 
0178 /*
0179  * Convert fan RPM value from sysfs into count value for fan controller
0180  * register (FAN_SET_CNT).
0181  */
0182 static inline unsigned char cnt_from_rpm(unsigned long rpm, u32 clk_freq, u16 p,
0183                      u8 clk_div, u8 gear_mult)
0184 {
0185     unsigned long f1 = clk_freq * 30 * gear_mult;
0186     unsigned long f2 = p * clk_div;
0187 
0188     if (!rpm)   /* to stop the fan, set cnt to 255 */
0189         return 0xff;
0190 
0191     rpm = clamp_val(rpm, f1 / (255 * f2), ULONG_MAX / f2);
0192     return DIV_ROUND_CLOSEST(f1, rpm * f2);
0193 }
0194 
0195 /* helper to grab and cache data, at most one time per second */
0196 static struct g762_data *g762_update_client(struct device *dev)
0197 {
0198     struct g762_data *data = dev_get_drvdata(dev);
0199     struct i2c_client *client = data->client;
0200     int ret = 0;
0201 
0202     mutex_lock(&data->update_lock);
0203     if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) &&
0204         likely(data->valid))
0205         goto out;
0206 
0207     ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT);
0208     if (ret < 0)
0209         goto out;
0210     data->set_cnt = ret;
0211 
0212     ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT);
0213     if (ret < 0)
0214         goto out;
0215     data->act_cnt = ret;
0216 
0217     ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA);
0218     if (ret < 0)
0219         goto out;
0220     data->fan_sta = ret;
0221 
0222     ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT);
0223     if (ret < 0)
0224         goto out;
0225     data->set_out = ret;
0226 
0227     ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1);
0228     if (ret < 0)
0229         goto out;
0230     data->fan_cmd1 = ret;
0231 
0232     ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2);
0233     if (ret < 0)
0234         goto out;
0235     data->fan_cmd2 = ret;
0236 
0237     data->last_updated = jiffies;
0238     data->valid = true;
0239  out:
0240     mutex_unlock(&data->update_lock);
0241 
0242     if (ret < 0) /* upon error, encode it in return value */
0243         data = ERR_PTR(ret);
0244 
0245     return data;
0246 }
0247 
0248 /* helpers for writing hardware parameters */
0249 
0250 /*
0251  * Set input clock frequency received on CLK pin of the chip. Accepted values
0252  * are between 0 and 0xffffff. If zero is given, then default frequency
0253  * (32,768Hz) is used. Note that clock frequency is a characteristic of the
0254  * system but an internal parameter, i.e. value is not passed to the device.
0255  */
0256 static int do_set_clk_freq(struct device *dev, unsigned long val)
0257 {
0258     struct g762_data *data = dev_get_drvdata(dev);
0259 
0260     if (val > 0xffffff)
0261         return -EINVAL;
0262     if (!val)
0263         val = 32768;
0264 
0265     data->clk_freq = val;
0266 
0267     return 0;
0268 }
0269 
0270 /* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */
0271 static int do_set_pwm_mode(struct device *dev, unsigned long val)
0272 {
0273     struct g762_data *data = g762_update_client(dev);
0274     int ret;
0275 
0276     if (IS_ERR(data))
0277         return PTR_ERR(data);
0278 
0279     mutex_lock(&data->update_lock);
0280     switch (val) {
0281     case G762_OUT_MODE_PWM:
0282         data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;
0283         break;
0284     case G762_OUT_MODE_DC:
0285         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
0286         break;
0287     default:
0288         ret = -EINVAL;
0289         goto out;
0290     }
0291     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
0292                     data->fan_cmd1);
0293     data->valid = false;
0294  out:
0295     mutex_unlock(&data->update_lock);
0296 
0297     return ret;
0298 }
0299 
0300 /* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
0301 static int do_set_fan_div(struct device *dev, unsigned long val)
0302 {
0303     struct g762_data *data = g762_update_client(dev);
0304     int ret;
0305 
0306     if (IS_ERR(data))
0307         return PTR_ERR(data);
0308 
0309     mutex_lock(&data->update_lock);
0310     switch (val) {
0311     case 1:
0312         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
0313         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
0314         break;
0315     case 2:
0316         data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
0317         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
0318         break;
0319     case 4:
0320         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
0321         data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
0322         break;
0323     case 8:
0324         data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
0325         data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
0326         break;
0327     default:
0328         ret = -EINVAL;
0329         goto out;
0330     }
0331     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
0332                     data->fan_cmd1);
0333     data->valid = false;
0334  out:
0335     mutex_unlock(&data->update_lock);
0336 
0337     return ret;
0338 }
0339 
0340 /* Set fan gear mode. Accepts either 0, 1 or 2. */
0341 static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
0342 {
0343     struct g762_data *data = g762_update_client(dev);
0344     int ret;
0345 
0346     if (IS_ERR(data))
0347         return PTR_ERR(data);
0348 
0349     mutex_lock(&data->update_lock);
0350     switch (val) {
0351     case 0:
0352         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
0353         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
0354         break;
0355     case 1:
0356         data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;
0357         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
0358         break;
0359     case 2:
0360         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
0361         data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
0362         break;
0363     default:
0364         ret = -EINVAL;
0365         goto out;
0366     }
0367     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
0368                     data->fan_cmd2);
0369     data->valid = false;
0370  out:
0371     mutex_unlock(&data->update_lock);
0372 
0373     return ret;
0374 }
0375 
0376 /* Set number of fan pulses per revolution. Accepts either 2 or 4. */
0377 static int do_set_fan_pulses(struct device *dev, unsigned long val)
0378 {
0379     struct g762_data *data = g762_update_client(dev);
0380     int ret;
0381 
0382     if (IS_ERR(data))
0383         return PTR_ERR(data);
0384 
0385     mutex_lock(&data->update_lock);
0386     switch (val) {
0387     case 2:
0388         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
0389         break;
0390     case 4:
0391         data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
0392         break;
0393     default:
0394         ret = -EINVAL;
0395         goto out;
0396     }
0397     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
0398                     data->fan_cmd1);
0399     data->valid = false;
0400  out:
0401     mutex_unlock(&data->update_lock);
0402 
0403     return ret;
0404 }
0405 
0406 /* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
0407 static int do_set_pwm_enable(struct device *dev, unsigned long val)
0408 {
0409     struct g762_data *data = g762_update_client(dev);
0410     int ret;
0411 
0412     if (IS_ERR(data))
0413         return PTR_ERR(data);
0414 
0415     mutex_lock(&data->update_lock);
0416     switch (val) {
0417     case G762_FAN_MODE_CLOSED_LOOP:
0418         data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
0419         break;
0420     case G762_FAN_MODE_OPEN_LOOP:
0421         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
0422         /*
0423          * BUG FIX: if SET_CNT register value is 255 then, for some
0424          * unknown reason, fan will not rotate as expected, no matter
0425          * the value of SET_OUT (to be specific, this seems to happen
0426          * only in PWM mode). To workaround this bug, we give SET_CNT
0427          * value of 254 if it is 255 when switching to open-loop.
0428          */
0429         if (data->set_cnt == 0xff)
0430             i2c_smbus_write_byte_data(data->client,
0431                           G762_REG_SET_CNT, 254);
0432         break;
0433     default:
0434         ret = -EINVAL;
0435         goto out;
0436     }
0437 
0438     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
0439                     data->fan_cmd1);
0440     data->valid = false;
0441  out:
0442     mutex_unlock(&data->update_lock);
0443 
0444     return ret;
0445 }
0446 
0447 /* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */
0448 static int do_set_pwm_polarity(struct device *dev, unsigned long val)
0449 {
0450     struct g762_data *data = g762_update_client(dev);
0451     int ret;
0452 
0453     if (IS_ERR(data))
0454         return PTR_ERR(data);
0455 
0456     mutex_lock(&data->update_lock);
0457     switch (val) {
0458     case G762_PWM_POLARITY_POSITIVE:
0459         data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
0460         break;
0461     case G762_PWM_POLARITY_NEGATIVE:
0462         data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
0463         break;
0464     default:
0465         ret = -EINVAL;
0466         goto out;
0467     }
0468     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
0469                     data->fan_cmd1);
0470     data->valid = false;
0471  out:
0472     mutex_unlock(&data->update_lock);
0473 
0474     return ret;
0475 }
0476 
0477 /*
0478  * Set pwm value. Accepts values between 0 (stops the fan) and
0479  * 255 (full speed). This only makes sense in open-loop mode.
0480  */
0481 static int do_set_pwm(struct device *dev, unsigned long val)
0482 {
0483     struct g762_data *data = dev_get_drvdata(dev);
0484     struct i2c_client *client = data->client;
0485     int ret;
0486 
0487     if (val > 255)
0488         return -EINVAL;
0489 
0490     mutex_lock(&data->update_lock);
0491     ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val);
0492     data->valid = false;
0493     mutex_unlock(&data->update_lock);
0494 
0495     return ret;
0496 }
0497 
0498 /*
0499  * Set fan RPM value. Can be called both in closed and open-loop mode
0500  * but effect will only be seen after closed-loop mode is configured.
0501  */
0502 static int do_set_fan_target(struct device *dev, unsigned long val)
0503 {
0504     struct g762_data *data = g762_update_client(dev);
0505     int ret;
0506 
0507     if (IS_ERR(data))
0508         return PTR_ERR(data);
0509 
0510     mutex_lock(&data->update_lock);
0511     data->set_cnt = cnt_from_rpm(val, data->clk_freq,
0512                      G762_PULSE_FROM_REG(data->fan_cmd1),
0513                      G762_CLKDIV_FROM_REG(data->fan_cmd1),
0514                      G762_GEARMULT_FROM_REG(data->fan_cmd2));
0515     ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT,
0516                     data->set_cnt);
0517     data->valid = false;
0518     mutex_unlock(&data->update_lock);
0519 
0520     return ret;
0521 }
0522 
0523 /* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
0524 static int do_set_fan_startv(struct device *dev, unsigned long val)
0525 {
0526     struct g762_data *data = g762_update_client(dev);
0527     int ret;
0528 
0529     if (IS_ERR(data))
0530         return PTR_ERR(data);
0531 
0532     mutex_lock(&data->update_lock);
0533     switch (val) {
0534     case 0:
0535         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
0536         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
0537         break;
0538     case 1:
0539         data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
0540         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
0541         break;
0542     case 2:
0543         data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
0544         data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
0545         break;
0546     case 3:
0547         data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
0548         data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
0549         break;
0550     default:
0551         ret = -EINVAL;
0552         goto out;
0553     }
0554     ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
0555                     data->fan_cmd2);
0556     data->valid = false;
0557  out:
0558     mutex_unlock(&data->update_lock);
0559 
0560     return ret;
0561 }
0562 
0563 /*
0564  * Helper to import hardware characteristics from .dts file and push
0565  * those to the chip.
0566  */
0567 
0568 #ifdef CONFIG_OF
0569 static const struct of_device_id g762_dt_match[] = {
0570     { .compatible = "gmt,g762" },
0571     { .compatible = "gmt,g763" },
0572     { },
0573 };
0574 MODULE_DEVICE_TABLE(of, g762_dt_match);
0575 
0576 /*
0577  * Grab clock (a required property), enable it, get (fixed) clock frequency
0578  * and store it. Note: upon success, clock has been prepared and enabled; it
0579  * must later be unprepared and disabled (e.g. during module unloading) by a
0580  * call to g762_of_clock_disable(). Note that a reference to clock is kept
0581  * in our private data structure to be used in this function.
0582  */
0583 static void g762_of_clock_disable(void *data)
0584 {
0585     struct g762_data *g762 = data;
0586 
0587     clk_disable_unprepare(g762->clk);
0588     clk_put(g762->clk);
0589 }
0590 
0591 static int g762_of_clock_enable(struct i2c_client *client)
0592 {
0593     struct g762_data *data;
0594     unsigned long clk_freq;
0595     struct clk *clk;
0596     int ret;
0597 
0598     if (!client->dev.of_node)
0599         return 0;
0600 
0601     clk = of_clk_get(client->dev.of_node, 0);
0602     if (IS_ERR(clk)) {
0603         dev_err(&client->dev, "failed to get clock\n");
0604         return PTR_ERR(clk);
0605     }
0606 
0607     ret = clk_prepare_enable(clk);
0608     if (ret) {
0609         dev_err(&client->dev, "failed to enable clock\n");
0610         goto clk_put;
0611     }
0612 
0613     clk_freq = clk_get_rate(clk);
0614     ret = do_set_clk_freq(&client->dev, clk_freq);
0615     if (ret) {
0616         dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);
0617         goto clk_unprep;
0618     }
0619 
0620     data = i2c_get_clientdata(client);
0621     data->clk = clk;
0622 
0623     devm_add_action(&client->dev, g762_of_clock_disable, data);
0624     return 0;
0625 
0626  clk_unprep:
0627     clk_disable_unprepare(clk);
0628 
0629  clk_put:
0630     clk_put(clk);
0631 
0632     return ret;
0633 }
0634 
0635 static int g762_of_prop_import_one(struct i2c_client *client,
0636                    const char *pname,
0637                    int (*psetter)(struct device *dev,
0638                           unsigned long val))
0639 {
0640     int ret;
0641     u32 pval;
0642 
0643     if (of_property_read_u32(client->dev.of_node, pname, &pval))
0644         return 0;
0645 
0646     dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);
0647     ret = (*psetter)(&client->dev, pval);
0648     if (ret)
0649         dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);
0650 
0651     return ret;
0652 }
0653 
0654 static int g762_of_prop_import(struct i2c_client *client)
0655 {
0656     int ret;
0657 
0658     if (!client->dev.of_node)
0659         return 0;
0660 
0661     ret = g762_of_prop_import_one(client, "fan_gear_mode",
0662                       do_set_fan_gear_mode);
0663     if (ret)
0664         return ret;
0665 
0666     ret = g762_of_prop_import_one(client, "pwm_polarity",
0667                       do_set_pwm_polarity);
0668     if (ret)
0669         return ret;
0670 
0671     return g762_of_prop_import_one(client, "fan_startv",
0672                        do_set_fan_startv);
0673 }
0674 
0675 #else
0676 static int g762_of_prop_import(struct i2c_client *client)
0677 {
0678     return 0;
0679 }
0680 
0681 static int g762_of_clock_enable(struct i2c_client *client)
0682 {
0683     return 0;
0684 }
0685 #endif
0686 
0687 /*
0688  * Helper to import hardware characteristics from .dts file and push
0689  * those to the chip.
0690  */
0691 
0692 static int g762_pdata_prop_import(struct i2c_client *client)
0693 {
0694     struct g762_platform_data *pdata = dev_get_platdata(&client->dev);
0695     int ret;
0696 
0697     if (!pdata)
0698         return 0;
0699 
0700     ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);
0701     if (ret)
0702         return ret;
0703 
0704     ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);
0705     if (ret)
0706         return ret;
0707 
0708     ret = do_set_fan_startv(&client->dev, pdata->fan_startv);
0709     if (ret)
0710         return ret;
0711 
0712     return do_set_clk_freq(&client->dev, pdata->clk_freq);
0713 }
0714 
0715 /*
0716  * sysfs attributes
0717  */
0718 
0719 /*
0720  * Read function for fan1_input sysfs file. Return current fan RPM value, or
0721  * 0 if fan is out of control.
0722  */
0723 static ssize_t fan1_input_show(struct device *dev,
0724                    struct device_attribute *da, char *buf)
0725 {
0726     struct g762_data *data = g762_update_client(dev);
0727     unsigned int rpm = 0;
0728 
0729     if (IS_ERR(data))
0730         return PTR_ERR(data);
0731 
0732     mutex_lock(&data->update_lock);
0733     /* reverse logic: fan out of control reporting is enabled low */
0734     if (data->fan_sta & G762_REG_FAN_STA_OOC) {
0735         rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,
0736                    G762_PULSE_FROM_REG(data->fan_cmd1),
0737                    G762_CLKDIV_FROM_REG(data->fan_cmd1),
0738                    G762_GEARMULT_FROM_REG(data->fan_cmd2));
0739     }
0740     mutex_unlock(&data->update_lock);
0741 
0742     return sprintf(buf, "%u\n", rpm);
0743 }
0744 
0745 /*
0746  * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
0747  * control mode i.e. PWM (1) or DC (0).
0748  */
0749 static ssize_t pwm1_mode_show(struct device *dev, struct device_attribute *da,
0750                   char *buf)
0751 {
0752     struct g762_data *data = g762_update_client(dev);
0753 
0754     if (IS_ERR(data))
0755         return PTR_ERR(data);
0756 
0757     return sprintf(buf, "%d\n",
0758                !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));
0759 }
0760 
0761 static ssize_t pwm1_mode_store(struct device *dev,
0762                    struct device_attribute *da, const char *buf,
0763                    size_t count)
0764 {
0765     unsigned long val;
0766     int ret;
0767 
0768     if (kstrtoul(buf, 10, &val))
0769         return -EINVAL;
0770 
0771     ret = do_set_pwm_mode(dev, val);
0772     if (ret < 0)
0773         return ret;
0774 
0775     return count;
0776 }
0777 
0778 /*
0779  * Read and write functions for fan1_div sysfs file. Get and set fan
0780  * controller prescaler value
0781  */
0782 static ssize_t fan1_div_show(struct device *dev, struct device_attribute *da,
0783                  char *buf)
0784 {
0785     struct g762_data *data = g762_update_client(dev);
0786 
0787     if (IS_ERR(data))
0788         return PTR_ERR(data);
0789 
0790     return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));
0791 }
0792 
0793 static ssize_t fan1_div_store(struct device *dev, struct device_attribute *da,
0794                   const char *buf, size_t count)
0795 {
0796     unsigned long val;
0797     int ret;
0798 
0799     if (kstrtoul(buf, 10, &val))
0800         return -EINVAL;
0801 
0802     ret = do_set_fan_div(dev, val);
0803     if (ret < 0)
0804         return ret;
0805 
0806     return count;
0807 }
0808 
0809 /*
0810  * Read and write functions for fan1_pulses sysfs file. Get and set number
0811  * of tachometer pulses per fan revolution.
0812  */
0813 static ssize_t fan1_pulses_show(struct device *dev,
0814                 struct device_attribute *da, char *buf)
0815 {
0816     struct g762_data *data = g762_update_client(dev);
0817 
0818     if (IS_ERR(data))
0819         return PTR_ERR(data);
0820 
0821     return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));
0822 }
0823 
0824 static ssize_t fan1_pulses_store(struct device *dev,
0825                  struct device_attribute *da, const char *buf,
0826                  size_t count)
0827 {
0828     unsigned long val;
0829     int ret;
0830 
0831     if (kstrtoul(buf, 10, &val))
0832         return -EINVAL;
0833 
0834     ret = do_set_fan_pulses(dev, val);
0835     if (ret < 0)
0836         return ret;
0837 
0838     return count;
0839 }
0840 
0841 /*
0842  * Read and write functions for pwm1_enable. Get and set fan speed control mode
0843  * (i.e. closed or open-loop).
0844  *
0845  * Following documentation about hwmon's sysfs interface, a pwm1_enable node
0846  * should accept the following:
0847  *
0848  *  0 : no fan speed control (i.e. fan at full speed)
0849  *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
0850  *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
0851  *
0852  * but we do not accept 0 as this mode is not natively supported by the chip
0853  * and it is not emulated by g762 driver. -EINVAL is returned in this case.
0854  */
0855 static ssize_t pwm1_enable_show(struct device *dev,
0856                 struct device_attribute *da, char *buf)
0857 {
0858     struct g762_data *data = g762_update_client(dev);
0859 
0860     if (IS_ERR(data))
0861         return PTR_ERR(data);
0862 
0863     return sprintf(buf, "%d\n",
0864                (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);
0865 }
0866 
0867 static ssize_t pwm1_enable_store(struct device *dev,
0868                  struct device_attribute *da, const char *buf,
0869                  size_t count)
0870 {
0871     unsigned long val;
0872     int ret;
0873 
0874     if (kstrtoul(buf, 10, &val))
0875         return -EINVAL;
0876 
0877     ret = do_set_pwm_enable(dev, val);
0878     if (ret < 0)
0879         return ret;
0880 
0881     return count;
0882 }
0883 
0884 /*
0885  * Read and write functions for pwm1 sysfs file. Get and set pwm value
0886  * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
0887  * makes it run at full speed.
0888  */
0889 static ssize_t pwm1_show(struct device *dev, struct device_attribute *da,
0890              char *buf)
0891 {
0892     struct g762_data *data = g762_update_client(dev);
0893 
0894     if (IS_ERR(data))
0895         return PTR_ERR(data);
0896 
0897     return sprintf(buf, "%d\n", data->set_out);
0898 }
0899 
0900 static ssize_t pwm1_store(struct device *dev, struct device_attribute *da,
0901               const char *buf, size_t count)
0902 {
0903     unsigned long val;
0904     int ret;
0905 
0906     if (kstrtoul(buf, 10, &val))
0907         return -EINVAL;
0908 
0909     ret = do_set_pwm(dev, val);
0910     if (ret < 0)
0911         return ret;
0912 
0913     return count;
0914 }
0915 
0916 /*
0917  * Read and write function for fan1_target sysfs file. Get/set the fan speed in
0918  * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
0919  * the fan speed using pulses from fan tachometer.
0920  *
0921  * Refer to rpm_from_cnt() implementation above to get info about count number
0922  * calculation.
0923  *
0924  * Also note that due to rounding errors it is possible that you don't read
0925  * back exactly the value you have set.
0926  */
0927 static ssize_t fan1_target_show(struct device *dev,
0928                 struct device_attribute *da, char *buf)
0929 {
0930     struct g762_data *data = g762_update_client(dev);
0931     unsigned int rpm;
0932 
0933     if (IS_ERR(data))
0934         return PTR_ERR(data);
0935 
0936     mutex_lock(&data->update_lock);
0937     rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,
0938                G762_PULSE_FROM_REG(data->fan_cmd1),
0939                G762_CLKDIV_FROM_REG(data->fan_cmd1),
0940                G762_GEARMULT_FROM_REG(data->fan_cmd2));
0941     mutex_unlock(&data->update_lock);
0942 
0943     return sprintf(buf, "%u\n", rpm);
0944 }
0945 
0946 static ssize_t fan1_target_store(struct device *dev,
0947                  struct device_attribute *da, const char *buf,
0948                  size_t count)
0949 {
0950     unsigned long val;
0951     int ret;
0952 
0953     if (kstrtoul(buf, 10, &val))
0954         return -EINVAL;
0955 
0956     ret = do_set_fan_target(dev, val);
0957     if (ret < 0)
0958         return ret;
0959 
0960     return count;
0961 }
0962 
0963 /* read function for fan1_fault sysfs file. */
0964 static ssize_t fan1_fault_show(struct device *dev, struct device_attribute *da,
0965                    char *buf)
0966 {
0967     struct g762_data *data = g762_update_client(dev);
0968 
0969     if (IS_ERR(data))
0970         return PTR_ERR(data);
0971 
0972     return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));
0973 }
0974 
0975 /*
0976  * read function for fan1_alarm sysfs file. Note that OOC condition is
0977  * enabled low
0978  */
0979 static ssize_t fan1_alarm_show(struct device *dev,
0980                    struct device_attribute *da, char *buf)
0981 {
0982     struct g762_data *data = g762_update_client(dev);
0983 
0984     if (IS_ERR(data))
0985         return PTR_ERR(data);
0986 
0987     return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));
0988 }
0989 
0990 static DEVICE_ATTR_RW(pwm1);
0991 static DEVICE_ATTR_RW(pwm1_mode);
0992 static DEVICE_ATTR_RW(pwm1_enable);
0993 static DEVICE_ATTR_RO(fan1_input);
0994 static DEVICE_ATTR_RO(fan1_alarm);
0995 static DEVICE_ATTR_RO(fan1_fault);
0996 static DEVICE_ATTR_RW(fan1_target);
0997 static DEVICE_ATTR_RW(fan1_div);
0998 static DEVICE_ATTR_RW(fan1_pulses);
0999 
1000 /* Driver data */
1001 static struct attribute *g762_attrs[] = {
1002     &dev_attr_fan1_input.attr,
1003     &dev_attr_fan1_alarm.attr,
1004     &dev_attr_fan1_fault.attr,
1005     &dev_attr_fan1_target.attr,
1006     &dev_attr_fan1_div.attr,
1007     &dev_attr_fan1_pulses.attr,
1008     &dev_attr_pwm1.attr,
1009     &dev_attr_pwm1_mode.attr,
1010     &dev_attr_pwm1_enable.attr,
1011     NULL
1012 };
1013 
1014 ATTRIBUTE_GROUPS(g762);
1015 
1016 /*
1017  * Enable both fan failure detection and fan out of control protection. The
1018  * function does not protect change/access to data structure; it must thus
1019  * only be called during initialization.
1020  */
1021 static inline int g762_fan_init(struct device *dev)
1022 {
1023     struct g762_data *data = g762_update_client(dev);
1024 
1025     if (IS_ERR(data))
1026         return PTR_ERR(data);
1027 
1028     data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
1029     data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
1030     data->valid = false;
1031 
1032     return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
1033                      data->fan_cmd1);
1034 }
1035 
1036 static int g762_probe(struct i2c_client *client)
1037 {
1038     struct device *dev = &client->dev;
1039     struct device *hwmon_dev;
1040     struct g762_data *data;
1041     int ret;
1042 
1043     if (!i2c_check_functionality(client->adapter,
1044                      I2C_FUNC_SMBUS_BYTE_DATA))
1045         return -ENODEV;
1046 
1047     data = devm_kzalloc(dev, sizeof(struct g762_data), GFP_KERNEL);
1048     if (!data)
1049         return -ENOMEM;
1050 
1051     i2c_set_clientdata(client, data);
1052     data->client = client;
1053     mutex_init(&data->update_lock);
1054 
1055     /* Enable fan failure detection and fan out of control protection */
1056     ret = g762_fan_init(dev);
1057     if (ret)
1058         return ret;
1059 
1060     /* Get configuration via DT ... */
1061     ret = g762_of_clock_enable(client);
1062     if (ret)
1063         return ret;
1064     ret = g762_of_prop_import(client);
1065     if (ret)
1066         return ret;
1067     /* ... or platform_data */
1068     ret = g762_pdata_prop_import(client);
1069     if (ret)
1070         return ret;
1071 
1072     hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
1073                                 data, g762_groups);
1074     return PTR_ERR_OR_ZERO(hwmon_dev);
1075 }
1076 
1077 static struct i2c_driver g762_driver = {
1078     .driver = {
1079         .name = DRVNAME,
1080         .of_match_table = of_match_ptr(g762_dt_match),
1081     },
1082     .probe_new = g762_probe,
1083     .id_table = g762_id,
1084 };
1085 
1086 module_i2c_driver(g762_driver);
1087 
1088 MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1089 MODULE_DESCRIPTION("GMT G762/G763 driver");
1090 MODULE_LICENSE("GPL");
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