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-rw-r--r--drivers/hwmon/g762.c1127
1 files changed, 1127 insertions, 0 deletions
diff --git a/drivers/hwmon/g762.c b/drivers/hwmon/g762.c
new file mode 100644
index 000000000..9b55e673b
--- /dev/null
+++ b/drivers/hwmon/g762.c
@@ -0,0 +1,1127 @@
+/*
+ * 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");