/* * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed * PWM controller chips from G762 family, i.e. G762 and G763 * * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org> * * This work is based on a basic version for 2.6.31 kernel developed * by Olivier Mouchet for LaCie. Updates and correction have been * performed to run on recent kernels. Additional features, like the * ability to configure various characteristics via .dts file or * board init file have been added. Detailed datasheet on which this * development is based is available here: * * http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf * * Headers from previous developments have been kept below: * * Copyright (c) 2009 LaCie * * Author: Olivier Mouchet <olivier.mouchet@gmail.com> * * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org> * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org> * * g762: minimal datasheet available at: * http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation. */ #include <linux/device.h> #include <linux/module.h> #include <linux/init.h> #include <linux/jiffies.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/kernel.h> #include <linux/clk.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_data/g762.h> #define DRVNAME "g762" static const struct i2c_device_id g762_id[] = { { "g762", 0 }, { "g763", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, g762_id); enum g762_regs { G762_REG_SET_CNT = 0x00, G762_REG_ACT_CNT = 0x01, G762_REG_FAN_STA = 0x02, G762_REG_SET_OUT = 0x03, G762_REG_FAN_CMD1 = 0x04, G762_REG_FAN_CMD2 = 0x05, }; /* Config register bits */ #define G762_REG_FAN_CMD1_DET_FAN_FAIL 0x80 /* enable fan_fail signal */ #define G762_REG_FAN_CMD1_DET_FAN_OOC 0x40 /* enable fan_out_of_control */ #define G762_REG_FAN_CMD1_OUT_MODE 0x20 /* out mode: PWM or DC */ #define G762_REG_FAN_CMD1_FAN_MODE 0x10 /* fan mode: closed/open-loop */ #define G762_REG_FAN_CMD1_CLK_DIV_ID1 0x08 /* clock divisor value */ #define G762_REG_FAN_CMD1_CLK_DIV_ID0 0x04 #define G762_REG_FAN_CMD1_PWM_POLARITY 0x02 /* PWM polarity */ #define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */ #define G762_REG_FAN_CMD2_GEAR_MODE_1 0x08 /* fan gear mode */ #define G762_REG_FAN_CMD2_GEAR_MODE_0 0x04 #define G762_REG_FAN_CMD2_FAN_STARTV_1 0x02 /* fan startup voltage */ #define G762_REG_FAN_CMD2_FAN_STARTV_0 0x01 #define G762_REG_FAN_STA_FAIL 0x02 /* fan fail */ #define G762_REG_FAN_STA_OOC 0x01 /* fan out of control */ /* Config register values */ #define G762_OUT_MODE_PWM 1 #define G762_OUT_MODE_DC 0 #define G762_FAN_MODE_CLOSED_LOOP 2 #define G762_FAN_MODE_OPEN_LOOP 1 #define G762_PWM_POLARITY_NEGATIVE 1 #define G762_PWM_POLARITY_POSITIVE 0 /* Register data is read (and cached) at most once per second. */ #define G762_UPDATE_INTERVAL HZ /* * Extract pulse count per fan revolution value (2 or 4) from given * FAN_CMD1 register value. */ #define G762_PULSE_FROM_REG(reg) \ ((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1) /* * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1 * register value. */ #define G762_CLKDIV_FROM_REG(reg) \ (1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 | \ G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2)) /* * Extract fan gear mode multiplier value (0, 2 or 4) from given * FAN_CMD2 register value. */ #define G762_GEARMULT_FROM_REG(reg) \ (1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 | \ G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2)) struct g762_data { struct device *hwmon_dev; struct i2c_client *client; struct clk *clk; /* update mutex */ struct mutex update_lock; /* board specific parameters. */ u32 clk_freq; /* g762 register cache */ bool valid; unsigned long last_updated; /* in jiffies */ u8 set_cnt; /* controls fan rotation speed in closed-loop mode */ u8 act_cnt; /* provides access to current fan RPM value */ u8 fan_sta; /* bit 0: set when actual fan speed is more than * 25% outside requested fan speed * bit 1: set when no transition occurs on fan * pin for 0.7s */ u8 set_out; /* controls fan rotation speed in open-loop mode */ u8 fan_cmd1; /* 0: FG_PLS_ID0 FG pulses count per revolution * 0: 2 counts per revolution * 1: 4 counts per revolution * 1: PWM_POLARITY 1: negative_duty * 0: positive_duty * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1] * 00: Divide fan clock by 1 * 01: Divide fan clock by 2 * 10: Divide fan clock by 4 * 11: Divide fan clock by 8 * 4: FAN_MODE 1:closed-loop, 0:open-loop * 5: OUT_MODE 1:PWM, 0:DC * 6: DET_FAN_OOC enable "fan ooc" status * 7: DET_FAN_FAIL enable "fan fail" status */ u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code * 2,3: FG_GEAR_MODE * 00: multiplier = 1 * 01: multiplier = 2 * 10: multiplier = 4 * 4: Mask ALERT# (g763 only) */ }; /* * Convert count value from fan controller register (FAN_SET_CNT) into fan * speed RPM value. Note that the datasheet documents a basic formula; * influence of additional parameters (fan clock divisor, fan gear mode) * have been infered from examples in the datasheet and tests. */ static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p, u8 clk_div, u8 gear_mult) { if (cnt == 0xff) /* setting cnt to 255 stops the fan */ return 0; return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div); } /* * Convert fan RPM value from sysfs into count value for fan controller * register (FAN_SET_CNT). */ static inline unsigned char cnt_from_rpm(u32 rpm, u32 clk_freq, u16 p, u8 clk_div, u8 gear_mult) { if (!rpm) /* to stop the fan, set cnt to 255 */ return 0xff; return clamp_val(((clk_freq * 30 * gear_mult) / (rpm * p * clk_div)), 0, 255); } /* helper to grab and cache data, at most one time per second */ static struct g762_data *g762_update_client(struct device *dev) { struct g762_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int ret = 0; mutex_lock(&data->update_lock); if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) && likely(data->valid)) goto out; ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT); if (ret < 0) goto out; data->set_cnt = ret; ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT); if (ret < 0) goto out; data->act_cnt = ret; ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA); if (ret < 0) goto out; data->fan_sta = ret; ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT); if (ret < 0) goto out; data->set_out = ret; ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1); if (ret < 0) goto out; data->fan_cmd1 = ret; ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2); if (ret < 0) goto out; data->fan_cmd2 = ret; data->last_updated = jiffies; data->valid = true; out: mutex_unlock(&data->update_lock); if (ret < 0) /* upon error, encode it in return value */ data = ERR_PTR(ret); return data; } /* helpers for writing hardware parameters */ /* * Set input clock frequency received on CLK pin of the chip. Accepted values * are between 0 and 0xffffff. If zero is given, then default frequency * (32,768Hz) is used. Note that clock frequency is a characteristic of the * system but an internal parameter, i.e. value is not passed to the device. */ static int do_set_clk_freq(struct device *dev, unsigned long val) { struct g762_data *data = dev_get_drvdata(dev); if (val > 0xffffff) return -EINVAL; if (!val) val = 32768; data->clk_freq = val; return 0; } /* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */ static int do_set_pwm_mode(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case G762_OUT_MODE_PWM: data->fan_cmd1 |= G762_REG_FAN_CMD1_OUT_MODE; break; case G762_OUT_MODE_DC: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */ static int do_set_fan_div(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case 1: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0; data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1; break; case 2: data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID0; data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1; break; case 4: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0; data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID1; break; case 8: data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID0; data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID1; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* Set fan gear mode. Accepts either 0, 1 or 2. */ static int do_set_fan_gear_mode(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case 0: data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0; data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1; break; case 1: data->fan_cmd2 |= G762_REG_FAN_CMD2_GEAR_MODE_0; data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1; break; case 2: data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0; data->fan_cmd2 |= G762_REG_FAN_CMD2_GEAR_MODE_1; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2, data->fan_cmd2); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* Set number of fan pulses per revolution. Accepts either 2 or 4. */ static int do_set_fan_pulses(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case 2: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV; break; case 4: data->fan_cmd1 |= G762_REG_FAN_CMD1_PULSE_PER_REV; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */ static int do_set_pwm_enable(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case G762_FAN_MODE_CLOSED_LOOP: data->fan_cmd1 |= G762_REG_FAN_CMD1_FAN_MODE; break; case G762_FAN_MODE_OPEN_LOOP: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE; /* * BUG FIX: if SET_CNT register value is 255 then, for some * unknown reason, fan will not rotate as expected, no matter * the value of SET_OUT (to be specific, this seems to happen * only in PWM mode). To workaround this bug, we give SET_CNT * value of 254 if it is 255 when switching to open-loop. */ if (data->set_cnt == 0xff) i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT, 254); break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */ static int do_set_pwm_polarity(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case G762_PWM_POLARITY_POSITIVE: data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY; break; case G762_PWM_POLARITY_NEGATIVE: data->fan_cmd1 |= G762_REG_FAN_CMD1_PWM_POLARITY; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* * Set pwm value. Accepts values between 0 (stops the fan) and * 255 (full speed). This only makes sense in open-loop mode. */ static int do_set_pwm(struct device *dev, unsigned long val) { struct g762_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int ret; if (val > 255) return -EINVAL; mutex_lock(&data->update_lock); ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val); data->valid = false; mutex_unlock(&data->update_lock); return ret; } /* * Set fan RPM value. Can be called both in closed and open-loop mode * but effect will only be seen after closed-loop mode is configured. */ static int do_set_fan_target(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); data->set_cnt = cnt_from_rpm(val, data->clk_freq, G762_PULSE_FROM_REG(data->fan_cmd1), G762_CLKDIV_FROM_REG(data->fan_cmd1), G762_GEARMULT_FROM_REG(data->fan_cmd2)); ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT, data->set_cnt); data->valid = false; mutex_unlock(&data->update_lock); return ret; } /* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */ static int do_set_fan_startv(struct device *dev, unsigned long val) { struct g762_data *data = g762_update_client(dev); int ret; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); switch (val) { case 0: data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0; data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1; break; case 1: data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_0; data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1; break; case 2: data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0; data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_1; break; case 3: data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_0; data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_1; break; default: ret = -EINVAL; goto out; } ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2, data->fan_cmd2); data->valid = false; out: mutex_unlock(&data->update_lock); return ret; } /* * Helper to import hardware characteristics from .dts file and push * those to the chip. */ #ifdef CONFIG_OF static const struct of_device_id g762_dt_match[] = { { .compatible = "gmt,g762" }, { .compatible = "gmt,g763" }, { }, }; /* * Grab clock (a required property), enable it, get (fixed) clock frequency * and store it. Note: upon success, clock has been prepared and enabled; it * must later be unprepared and disabled (e.g. during module unloading) by a * call to g762_of_clock_disable(). Note that a reference to clock is kept * in our private data structure to be used in this function. */ static int g762_of_clock_enable(struct i2c_client *client) { struct g762_data *data; unsigned long clk_freq; struct clk *clk; int ret; if (!client->dev.of_node) return 0; clk = of_clk_get(client->dev.of_node, 0); if (IS_ERR(clk)) { dev_err(&client->dev, "failed to get clock\n"); return PTR_ERR(clk); } ret = clk_prepare_enable(clk); if (ret) { dev_err(&client->dev, "failed to enable clock\n"); goto clk_put; } clk_freq = clk_get_rate(clk); ret = do_set_clk_freq(&client->dev, clk_freq); if (ret) { dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq); goto clk_unprep; } data = i2c_get_clientdata(client); data->clk = clk; return 0; clk_unprep: clk_disable_unprepare(clk); clk_put: clk_put(clk); return ret; } static void g762_of_clock_disable(struct i2c_client *client) { struct g762_data *data = i2c_get_clientdata(client); if (!data->clk) return; clk_disable_unprepare(data->clk); clk_put(data->clk); } static int g762_of_prop_import_one(struct i2c_client *client, const char *pname, int (*psetter)(struct device *dev, unsigned long val)) { int ret; u32 pval; if (of_property_read_u32(client->dev.of_node, pname, &pval)) return 0; dev_dbg(&client->dev, "found %s (%d)\n", pname, pval); ret = (*psetter)(&client->dev, pval); if (ret) dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval); return ret; } static int g762_of_prop_import(struct i2c_client *client) { int ret; if (!client->dev.of_node) return 0; ret = g762_of_prop_import_one(client, "fan_gear_mode", do_set_fan_gear_mode); if (ret) return ret; ret = g762_of_prop_import_one(client, "pwm_polarity", do_set_pwm_polarity); if (ret) return ret; return g762_of_prop_import_one(client, "fan_startv", do_set_fan_startv); } #else static int g762_of_prop_import(struct i2c_client *client) { return 0; } static int g762_of_clock_enable(struct i2c_client *client) { return 0; } static void g762_of_clock_disable(struct i2c_client *client) { } #endif /* * Helper to import hardware characteristics from .dts file and push * those to the chip. */ static int g762_pdata_prop_import(struct i2c_client *client) { struct g762_platform_data *pdata = dev_get_platdata(&client->dev); int ret; if (!pdata) return 0; ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode); if (ret) return ret; ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity); if (ret) return ret; ret = do_set_fan_startv(&client->dev, pdata->fan_startv); if (ret) return ret; return do_set_clk_freq(&client->dev, pdata->clk_freq); } /* * sysfs attributes */ /* * Read function for fan1_input sysfs file. Return current fan RPM value, or * 0 if fan is out of control. */ static ssize_t get_fan_rpm(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); unsigned int rpm = 0; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); /* reverse logic: fan out of control reporting is enabled low */ if (data->fan_sta & G762_REG_FAN_STA_OOC) { rpm = rpm_from_cnt(data->act_cnt, data->clk_freq, G762_PULSE_FROM_REG(data->fan_cmd1), G762_CLKDIV_FROM_REG(data->fan_cmd1), G762_GEARMULT_FROM_REG(data->fan_cmd2)); } mutex_unlock(&data->update_lock); return sprintf(buf, "%u\n", rpm); } /* * Read and write functions for pwm1_mode sysfs file. Get and set fan speed * control mode i.e. PWM (1) or DC (0). */ static ssize_t get_pwm_mode(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE)); } static ssize_t set_pwm_mode(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_pwm_mode(dev, val); if (ret < 0) return ret; return count; } /* * Read and write functions for fan1_div sysfs file. Get and set fan * controller prescaler value */ static ssize_t get_fan_div(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1)); } static ssize_t set_fan_div(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_fan_div(dev, val); if (ret < 0) return ret; return count; } /* * Read and write functions for fan1_pulses sysfs file. Get and set number * of tachometer pulses per fan revolution. */ static ssize_t get_fan_pulses(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1)); } static ssize_t set_fan_pulses(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_fan_pulses(dev, val); if (ret < 0) return ret; return count; } /* * Read and write functions for pwm1_enable. Get and set fan speed control mode * (i.e. closed or open-loop). * * Following documentation about hwmon's sysfs interface, a pwm1_enable node * should accept followings: * * 0 : no fan speed control (i.e. fan at full speed) * 1 : manual fan speed control enabled (use pwm[1-*]) (open-loop) * 2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop) * * but we do not accept 0 as this mode is not natively supported by the chip * and it is not emulated by g762 driver. -EINVAL is returned in this case. */ static ssize_t get_pwm_enable(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1); } static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_pwm_enable(dev, val); if (ret < 0) return ret; return count; } /* * Read and write functions for pwm1 sysfs file. Get and set pwm value * (which affects fan speed) in open-loop mode. 0 stops the fan and 255 * makes it run at full speed. */ static ssize_t get_pwm(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%d\n", data->set_out); } static ssize_t set_pwm(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_pwm(dev, val); if (ret < 0) return ret; return count; } /* * Read and write function for fan1_target sysfs file. Get/set the fan speed in * closed-loop mode. Speed is given as a RPM value; then the chip will regulate * the fan speed using pulses from fan tachometer. * * Refer to rpm_from_cnt() implementation above to get info about count number * calculation. * * Also note that due to rounding errors it is possible that you don't read * back exactly the value you have set. */ static ssize_t get_fan_target(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); unsigned int rpm; if (IS_ERR(data)) return PTR_ERR(data); mutex_lock(&data->update_lock); rpm = rpm_from_cnt(data->set_cnt, data->clk_freq, G762_PULSE_FROM_REG(data->fan_cmd1), G762_CLKDIV_FROM_REG(data->fan_cmd1), G762_GEARMULT_FROM_REG(data->fan_cmd2)); mutex_unlock(&data->update_lock); return sprintf(buf, "%u\n", rpm); } static ssize_t set_fan_target(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { unsigned long val; int ret; if (kstrtoul(buf, 10, &val)) return -EINVAL; ret = do_set_fan_target(dev, val); if (ret < 0) return ret; return count; } /* read function for fan1_fault sysfs file. */ static ssize_t get_fan_failure(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL)); } /* * read function for fan1_alarm sysfs file. Note that OOC condition is * enabled low */ static ssize_t get_fan_ooc(struct device *dev, struct device_attribute *da, char *buf) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC)); } static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, get_pwm_mode, set_pwm_mode); static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_pwm_enable, set_pwm_enable); static DEVICE_ATTR(fan1_input, S_IRUGO, get_fan_rpm, NULL); static DEVICE_ATTR(fan1_alarm, S_IRUGO, get_fan_ooc, NULL); static DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_failure, NULL); static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_fan_target, set_fan_target); static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_fan_div, set_fan_div); static DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO, get_fan_pulses, set_fan_pulses); /* Driver data */ static struct attribute *g762_attrs[] = { &dev_attr_fan1_input.attr, &dev_attr_fan1_alarm.attr, &dev_attr_fan1_fault.attr, &dev_attr_fan1_target.attr, &dev_attr_fan1_div.attr, &dev_attr_fan1_pulses.attr, &dev_attr_pwm1.attr, &dev_attr_pwm1_mode.attr, &dev_attr_pwm1_enable.attr, NULL }; ATTRIBUTE_GROUPS(g762); /* * Enable both fan failure detection and fan out of control protection. The * function does not protect change/access to data structure; it must thus * only be called during initialization. */ static inline int g762_fan_init(struct device *dev) { struct g762_data *data = g762_update_client(dev); if (IS_ERR(data)) return PTR_ERR(data); data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL; data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC; data->valid = false; return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1, data->fan_cmd1); } static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct g762_data *data; int ret; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; data = devm_kzalloc(dev, sizeof(struct g762_data), GFP_KERNEL); if (!data) return -ENOMEM; i2c_set_clientdata(client, data); data->client = client; mutex_init(&data->update_lock); /* Enable fan failure detection and fan out of control protection */ ret = g762_fan_init(dev); if (ret) return ret; /* Get configuration via DT ... */ ret = g762_of_clock_enable(client); if (ret) return ret; ret = g762_of_prop_import(client); if (ret) goto clock_dis; /* ... or platform_data */ ret = g762_pdata_prop_import(client); if (ret) goto clock_dis; data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name, data, g762_groups); if (IS_ERR(data->hwmon_dev)) { ret = PTR_ERR(data->hwmon_dev); goto clock_dis; } return 0; clock_dis: g762_of_clock_disable(client); return ret; } static int g762_remove(struct i2c_client *client) { struct g762_data *data = i2c_get_clientdata(client); hwmon_device_unregister(data->hwmon_dev); g762_of_clock_disable(client); return 0; } static struct i2c_driver g762_driver = { .driver = { .name = DRVNAME, .owner = THIS_MODULE, .of_match_table = of_match_ptr(g762_dt_match), }, .probe = g762_probe, .remove = g762_remove, .id_table = g762_id, }; module_i2c_driver(g762_driver); MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>"); MODULE_DESCRIPTION("GMT G762/G763 driver"); MODULE_LICENSE("GPL");