[PATCH 3/5] i8k: Add support for configurable maximum fan speed value

From: Guenter Roeck
Date: Sat Jun 21 2014 - 11:09:25 EST


Newer Dell systems provide more granular fan speed selection.
Add support for it.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/char/i8k.c | 49 ++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index 14ca8f0..0b69da0 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -65,6 +65,8 @@ static char bios_version[4];
static struct device *i8k_hwmon_dev;
static u32 i8k_hwmon_flags;
static int i8k_fan_mult;
+static int i8k_pwm_mult;
+static int i8k_fan_max = I8K_FAN_HIGH;

#define I8K_HWMON_HAVE_TEMP1 (1 << 0)
#define I8K_HWMON_HAVE_TEMP2 (1 << 1)
@@ -97,6 +99,10 @@ static int fan_mult = I8K_FAN_MULT;
module_param(fan_mult, int, 0);
MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");

+static int fan_max = I8K_FAN_HIGH;
+module_param(fan_max, int, 0);
+MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed");
+
static int i8k_open_fs(struct inode *inode, struct file *file);
static long i8k_ioctl(struct file *, unsigned int, unsigned long);

@@ -276,7 +282,7 @@ static int i8k_set_fan(int fan, int speed)
{
struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };

- speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
+ speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
regs.ebx = (fan & 0xff) | (speed << 8);

return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
@@ -521,7 +527,7 @@ static ssize_t i8k_hwmon_show_pwm(struct device *dev,
status = i8k_get_fan_status(index);
if (status < 0)
return -EIO;
- return sprintf(buf, "%d\n", clamp_val(status * 128, 0, 255));
+ return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
}

static ssize_t i8k_hwmon_set_pwm(struct device *dev,
@@ -535,7 +541,7 @@ static ssize_t i8k_hwmon_set_pwm(struct device *dev,
err = kstrtoul(buf, 10, &val);
if (err)
return err;
- val = clamp_val(DIV_ROUND_CLOSEST(val, 128), 0, 2);
+ val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);

mutex_lock(&i8k_mutex);
err = i8k_set_fan(index, val);
@@ -638,6 +644,27 @@ static int __init i8k_init_hwmon(void)
return 0;
}

+struct i8k_config_data {
+ int fan_mult;
+ int fan_max;
+};
+
+enum i8k_configs {
+ DELL_STUDIO,
+ DELL_XPS_M140,
+};
+
+static const struct i8k_config_data i8k_config_data[] = {
+ [DELL_STUDIO] = {
+ .fan_mult = 1,
+ .fan_max = I8K_FAN_HIGH,
+ },
+ [DELL_XPS_M140] = {
+ .fan_mult = 1,
+ .fan_max = I8K_FAN_HIGH,
+ },
+};
+
static struct dmi_system_id i8k_dmi_table[] __initdata = {
{
.ident = "Dell Inspiron",
@@ -708,7 +735,7 @@ static struct dmi_system_id i8k_dmi_table[] __initdata = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
},
- .driver_data = (void *)1, /* fan multiplier override */
+ .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
},
{
.ident = "Dell XPS M140",
@@ -716,7 +743,7 @@ static struct dmi_system_id i8k_dmi_table[] __initdata = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
},
- .driver_data = (void *)1, /* fan multiplier override */
+ .driver_data = (void *)&i8k_config_data[DELL_XPS_M140],
},
{ }
};
@@ -756,9 +783,17 @@ static int __init i8k_probe(void)
}

i8k_fan_mult = fan_mult;
+ i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
id = dmi_first_match(i8k_dmi_table);
- if (id && fan_mult == I8K_FAN_MULT && id->driver_data)
- i8k_fan_mult = (unsigned long)id->driver_data;
+ if (id && id->driver_data) {
+ const struct i8k_config_data *conf = id->driver_data;
+
+ if (fan_mult == I8K_FAN_MULT && conf->fan_mult)
+ i8k_fan_mult = conf->fan_mult;
+ if (fan_max == I8K_FAN_HIGH && conf->fan_max)
+ i8k_fan_max = conf->fan_max;
+ }
+ i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);

return 0;
}
--
1.9.1

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