[PATCHv7 1/1] Add support for GMT G762/G763 PWM fan controllers
Guenter Roeck
linux at roeck-us.net
Thu Jun 20 11:38:23 EST 2013
On Wed, Jun 19, 2013 at 09:34:34PM +0200, Arnaud Ebalard wrote:
>
> GMT G762/763 fan speed PWM controller is connected directly to a fan
> and performs closed-loop or open-loop control of the fan speed. Two
> modes - PWM or DC - are supported by the chip. Introduced driver
> provides various knobs to control the operations of the chip (via
> sysfs interface). Specific characteristics of the system can be passed
> either using board init code or via DT. Documentation for both the
> driver and DT bindings are also provided.
>
> Signed-off-by: Arnaud Ebalard <arno at natisbad.org>
Couple of additional nitpicks plus a bug.
Guenter
> ---
>
> Changes since v6:
> s/data->clk/data->clk_freq/
> cache clk in struct g762_data to avoid unecessary call to of_clk_get()
> add missing calls to clk_put() where necessary
> fixed some comments
>
> Changes since v5:
> fixed useless ret parameter init in various functions
> removed useless goto in favour of direct return
> enable fan detection and fan ooc protection in an init function
> fixed patch version (previous v5 was mistakenly named v4)
> correctly balance clk_prepare_enable() by clk_disable_unprepare()
> more tests w/o CONFIG_OF and with driver as module (load/unload)
>
> Changes since v4:
> Removed unused defines
> fixed some comments
> s/pwm_freq/clk_freq/g and fixed associated comments
> removed useless settings of data->valid to false
> do not hide original return code in g762_one_prop_commit()
> replaced ref_clk property by a required reference to a clock in .dts
> drop fan_pulses property in DT and provide sysfs attribute
> removed whole G762_VAL_TEST_BIT hack
> still not supporting 0 for pwm_enable: fixed comment
> fixed comment for get/set_pwm()
> fixed reversed polarity setter logic
> simplified do_set_pwm()
> merged all three patches into one
> Fixed issue reported by Simon (open-loop not working when set_cnt is 255)
>
> Changes since v3:
> set is against current head of Linus tree
> removed dev_err() calls when i2c_smbus_read/write_byte_data() fails
> pwm1 sets SET_OUT reg, fan1_target sets SET_CNT reg, both unconditionally
> removed all DT and platform_data knobs available via sysfs
> updated documentation files to reflect two previous changes
>
> Changes since v2:
> set ref_clk value to 32768 if not overloaded
> fixed multi-line comment format in g762.h
> removed static const G762_DEFAULT_PDATA in g762.h for a function
> CodingStyle: add spaces between operatoirs when missing
> check return value of i2c_smbus_{read,write}_byte_data()
> remove { } is not needed in single-statement conditionals
> introduced G762_ATTR_VAL() to allow sparse init of platform_data struc
> changed missed reference to linear mode for DC mode
>
> Changes since v1
> Changed author
> removed bad tabs
> Provide datasheet link w/o fud in g762 documentation
> removed documentation for removed fan_gear_mode sysfs entry
> removed tested-by from patch
> removed FSF address in header file
> removed useless include of <linux/slab.h>
> removed useless parenthesis against HZ in define
> use spaces around binary operators
> use i2c_smbus_{read,write}_byte_data() instead of g762_{read,write}_value()
> use return value of i2c_smbus_write_byte_data()
> use true for initializing boolean
> removed useless blank lines
> do not enforce single return point rule where less readable
> use dev_err() and dev_dbg() instead of dev_info() when it makes sense
> remove leading '&' for function passed as pointers
> allow passing parameter via platform_data struct for non-DT enabled boards
> set data->valid to false when config is modified
> s/linear/DC/ for mode (g762 datasheet uses linear)
> more tests on rpm_from_cnt() and cnt_from_rpm() formula
> dont overload
>
> Changes since v0
> removed forward declaration
> use bool for valid field instead of bit field.
> protect macro args
> fixed typo in subject line
> Added mention for G763 support in Kconfig
> fixed typo in driver name in Kconfig
> do not use DRVNAME in i2c_device_id g762_id[]
> Following discussions, kept DEVICE_ATTR (no switch to SENSOR_DEVICE_ATTR)
> removed useless casts when flipping bit values
> Sanity check user input value (e.g. to prevent 256 to silenty become 0)
> Added extra lines for multi line comments when needed
> removed various testing knobs
> make removed knobs available via DT
> passed checkpatch script on the patch
> removed useless lock protection againt clk setting
> moved all setter at the beginning of the file
> removed bad (u16) casts in g762_write_value() calls
>
>
>
> Documentation/devicetree/bindings/hwmon/g762.txt | 47 +
> Documentation/hwmon/g762 | 65 ++
> drivers/hwmon/Kconfig | 10 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/g762.c | 1151 ++++++++++++++++++++++
> include/linux/platform_data/g762.h | 37 +
> 6 files changed, 1311 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/g762.txt
> create mode 100644 Documentation/hwmon/g762
> create mode 100644 drivers/hwmon/g762.c
> create mode 100644 include/linux/platform_data/g762.h
>
> diff --git a/Documentation/devicetree/bindings/hwmon/g762.txt b/Documentation/devicetree/bindings/hwmon/g762.txt
> new file mode 100644
> index 0000000..25cc6d8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/g762.txt
> @@ -0,0 +1,47 @@
> +GMT G762/G763 PWM Fan controller
> +
> +Required node properties:
> +
> + - "compatible": must be either "gmt,g762" or "gmt,g763"
> + - "reg": I2C bus address of the device
> + - "clocks": a fixed clock providing input clock frequency
> + on CLK pin of the chip.
> +
> +Optional properties:
> +
> + - "fan_startv": fan startup voltage. Accepted values are 0, 1, 2 and 3.
> + The higher the more.
> +
> + - "pwm_polarity": pwm polarity. Accepted values are 0 (positive duty)
> + and 1 (negative duty).
> +
> + - "fan_gear_mode": fan gear mode. Supported values are 0, 1 and 2.
> +
> +If an optional property is not set in .dts file, then current value is kept
> +unmodified (e.g. u-boot installed value).
> +
> +Additional information on operational parameters for the device is available
> +in Documentation/hwmon/g762. A detailed datasheet for the device is available
> +at http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf.
> +
> +Example g762 node:
> +
> + clocks {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + g762_clk: fixedclk {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <8192>;
> + }
> + }
> +
> + g762: g762 at 3e {
> + compatible = "gmt,g762";
> + reg = <0x3e>;
> + clocks = <&g762_clk>
> + fan_gear_mode = <0>; /* chip default */
> + fan_startv = <1>; /* chip default */
> + pwm_polarity = <0>; /* chip default */
> + };
> diff --git a/Documentation/hwmon/g762 b/Documentation/hwmon/g762
> new file mode 100644
> index 0000000..923db9c
> --- /dev/null
> +++ b/Documentation/hwmon/g762
> @@ -0,0 +1,65 @@
> +Kernel driver g762
> +==================
> +
> +The GMT G762 Fan Speed PWM Controller is connected directly to a fan
> +and performs closed-loop or open-loop control of the fan speed. Two
> +modes - PWM or DC - are supported by the device.
> +
> +For additional information, a detailed datasheet is available at
> +http://natisbad.org/NAS/ref/GMT_EDS-762_763-080710-0.2.pdf. sysfs
> +bindings are described in Documentation/hwmon/sysfs-interface.
> +
> +The following entries are available to the user in a subdirectory of
> +/sys/bus/i2c/drivers/g762/ to control the operation of the device.
> +This can be done manually using the following entries but is usually
> +done via a userland daemon like fancontrol.
> +
> +Note that those entries do not provide ways to setup the specific
> +hardware characteristics of the system (reference clock, pulses per
> +fan revolution, ...); Those can be modified via devicetree bindings
> +documented in Documentation/devicetree/bindings/hwmon/g762.txt or
> +using a specific platform_data structure in board initialization
> +file (see include/linux/platform_data/g762.h).
> +
> + fan1_target: set desired fan speed. This only makes sense in closed-loop
> + fan speed control (i.e. when pwm1_enable is set to 2).
> +
> + fan1_input: provide current fan rotation value in RPM as reported by
> + the fan to the device.
> +
> + fan1_div: fan clock divisor. Supported value are 1, 2, 4 and 8.
> +
> + fan1_pulses: number of pulses per fan revolution. Supported values
> + are 2 and 4.
> +
> + fan1_fault: reports fan failure, i.e. no transition on fan gear pin for
> + about 0.7s (if the fan is not voluntarily set off).
> +
> + fan1_alarm: in closed-loop control mode, if fan RPM value is 25% out
> + of the programmed value for over 6 seconds 'fan1_alarm' is
> + set to 1.
> +
> + pwm1_enable: set current fan speed control mode i.e. 1 for manual fan
> + speed control (open-loop) via pwm1 described below, 2 for
> + automatic fan speed control (closed-loop) via fan1_target
> + above.
> +
> + pwm1_mode: set or get fan driving mode: 1 for PWM mode, 0 for DC mode.
> +
> + pwm1: get or set PWM fan control value in open-loop mode. This is an
> + integer value between 0 and 255. 0 stops the fan, 255 makes
> + it run at full speed.
> +
> +Both in PWM mode ('pwm1_mode' set to 1) and DC mode ('pwm1_mode' set to 0),
> +when current fan speed control mode is open-loop ('pwm1_enable' set to 1),
> +the fan speed is programmed by setting a value between 0 and 255 via 'pwm1'
> +entry (0 stops the fan, 255 makes it run at full speed). In closed-loop mode
> +('pwm1_enable' set to 2), the expected rotation speed in RPM can be passed to
> +the chip via 'fan1_target'. In closed-loop mode, the target speed is compared
> +with current speed (available via 'fan1_input') by the device and a feedback
> +is performed to match that target value. The fan speed value is computed
> +based on the parameters associated with the physical characteristics of the
> +system: a reference clock source frequency, a number of pulses per fan
> +revolution, etc.
> +
> +Note that the driver will update its values at most once per second.
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 0428e8a..142bdf8 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -456,6 +456,16 @@ config SENSORS_G760A
> This driver can also be built as a module. If so, the module
> will be called g760a.
>
> +config SENSORS_G762
> + tristate "GMT G762 and G763"
> + depends on I2C
> + help
> + If you say yes here you get support for Global Mixed-mode
> + Technology Inc G762 and G763 fan speed PWM controller chips.
> +
> + This driver can also be built as a module. If so, the module
> + will be called g762.
> +
> config SENSORS_GL518SM
> tristate "Genesys Logic GL518SM"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index d17d3e6..4f0fb52 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -60,6 +60,7 @@ obj-$(CONFIG_SENSORS_F75375S) += f75375s.o
> obj-$(CONFIG_SENSORS_FAM15H_POWER) += fam15h_power.o
> obj-$(CONFIG_SENSORS_FSCHMD) += fschmd.o
> obj-$(CONFIG_SENSORS_G760A) += g760a.o
> +obj-$(CONFIG_SENSORS_G762) += g762.o
> obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o
> obj-$(CONFIG_SENSORS_GL520SM) += gl520sm.o
> obj-$(CONFIG_SENSORS_GPIO_FAN) += gpio-fan.o
> diff --git a/drivers/hwmon/g762.c b/drivers/hwmon/g762.c
> new file mode 100644
> index 0000000..f111420
> --- /dev/null
> +++ b/drivers/hwmon/g762.c
> @@ -0,0 +1,1151 @@
> +/*
> + * 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 at 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 at gmail.com>
> + *
> + * based on g760a code written by Herbert Valerio Riedel <hvr at gnu.org>
> + * Copyright (C) 2007 Herbert Valerio Riedel <hvr at 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 i2c_client *client;
> + struct device *hwmon_dev;
> + 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 i2c_client *client = to_i2c_client(dev);
> + struct g762_data *data = i2c_get_clientdata(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 i2c_client *client = to_i2c_client(dev);
> + struct g762_data *data = i2c_get_clientdata(client);
> +
> + 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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + 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(client, G762_REG_SET_CNT,
> + 254);
> + break;
> + default:
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = i2c_smbus_write_byte_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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + struct g762_data *data = i2c_get_clientdata(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 i2c_client *client = to_i2c_client(dev);
> + 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(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 i2c_client *client = to_i2c_client(dev);
> + 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(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 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 ret;
> +
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;
Guess this should be
if (!data->clk)
return;
Small but significant difference ...
> +
> + 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))
> +{
> + const __be32 *prop;
> + int len, ret;
> + u32 pval;
> +
> + prop = of_get_property(client->dev.of_node, pname, &len);
> + if (!prop || len != sizeof(u32))
> + return 0;
> +
> + pval = be32_to_cpu(prop[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 = client->dev.platform_data;
> + 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;
> + ssize_t ret;
> +
> + 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));
> + ret = sprintf(buf, "%u\n", rpm);
> + mutex_unlock(&data->update_lock);
> +
> + return ret;
This would be better written as:
mutex_unlock(&data->update_lock);
return sprintf(buf, "%u\n", rpm);
Releases the mutex earlier, and you don't need the ret variable.
> +}
> +
> +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_attributes[] = {
> + &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
> +};
> +
> +static const struct attribute_group g762_group = {
> + .attrs = g762_attributes,
> +};
> +
> +/* Enable both fan failure detection and fan out of control protection */
> +static inline int g762_fan_init(struct device *dev)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct g762_data *data = g762_update_client(dev);
> + int ret;
> +
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> +
> + mutex_lock(&data->update_lock);
This will never run more than once, so the mutex protection is not needed.
Drop it and add a note that the function must only be called during
initialization.
> + data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
> + data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
The douple spaces above don't really serve a purpose anymore.
> + ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
> + data->fan_cmd1);
> + data->valid = false;
> + mutex_unlock(&data->update_lock);
> +
> + return ret;
> +}
> +
> +static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)
> +{
> + struct g762_data *data;
> + int ret;
> +
> + if (!i2c_check_functionality(client->adapter,
> + I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + data = devm_kzalloc(&client->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(&client->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;
> +
> + /* Register sysfs hooks */
> + ret = sysfs_create_group(&client->dev.kobj, &g762_group);
> + if (ret)
> + goto clock_dis;
> +
> + data->hwmon_dev = hwmon_device_register(&client->dev);
> + if (IS_ERR(data->hwmon_dev)) {
> + ret = PTR_ERR(data->hwmon_dev);
> + goto sysfs_rem;
> + }
> +
> + return 0;
> +
> + sysfs_rem:
> + sysfs_remove_group(&client->dev.kobj, &g762_group);
> +
> + 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);
> + sysfs_remove_group(&client->dev.kobj, &g762_group);
> + 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 at natisbad.org>");
> +MODULE_DESCRIPTION("GMT G762/G763 driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/platform_data/g762.h b/include/linux/platform_data/g762.h
> new file mode 100644
> index 0000000..d3c5128
> --- /dev/null
> +++ b/include/linux/platform_data/g762.h
> @@ -0,0 +1,37 @@
> +/*
> + * Platform data structure for g762 fan controller driver
> + *
> + * Copyright (C) 2013, Arnaud EBALARD <arno at natisbad.org>
> + *
> + * 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, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +#ifndef __LINUX_PLATFORM_DATA_G762_H__
> +#define __LINUX_PLATFORM_DATA_G762_H__
> +
> +/*
> + * Following structure can be used to set g762 driver platform specific data
> + * during board init. Note that passing a sparse structure is possible but
> + * will result in non-specified attributes to be set to default value, hence
> + * overloading those installed during boot (e.g. by u-boot).
> + */
> +
> +struct g762_platform_data {
> + u32 fan_startv;
> + u32 fan_gear_mode;
> + u32 pwm_polarity;
> + u32 clk_freq;
> +};
> +
> +#endif /* __LINUX_PLATFORM_DATA_G762_H__ */
> --
> 1.7.10.4
>
>
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