On 19-08-16 04:43, Guenter Roeck wrote:
On 08/16/2016 12:20 AM, Mike Looijmans wrote:Parse devicetree parameters for voltage and prescaler setting. This allows using multiple max6550 devices with varying settings, and also makes it possible to instantiate and configure the device using devicetree.Signed-off-by: Mike Looijmans <[email protected]> --- v4: Vendor prefix "maxim," for devicetree properties and compatible string Split documentation into separate patch v3: Resubmit because wrong mailing lists used Fix style errors as reported by checkpatch.pl Fix bug in DT parsing of fan-prescale v2: Add devicetree binding documentation Code changes as suggested by Guenter Reduce log info, output only a single line drivers/hwmon/max6650.c | 47 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 11 deletions(-) diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c index 162a520..6beb62c 100644 --- a/drivers/hwmon/max6650.c +++ b/drivers/hwmon/max6650.c @@ -39,6 +39,7 @@ #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> +#include <linux/of_device.h> /* * Insmod parameters @@ -48,7 +49,7 @@ static int fan_voltage; /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ static int prescaler; -/* clock: The clock frequency of the chip the driver should assume */ +/* clock: The clock frequency of the chip (max6651 can be clocked externally) */ static int clock = 254000; module_param(fan_voltage, int, S_IRUGO); @@ -133,6 +134,19 @@ static const u8 tach_reg[] = { MAX6650_REG_TACH3, }; +static const struct of_device_id max6650_dt_match[] = { + { + .compatible = "maxim,max6650", + .data = (void *)1 + }, + { + .compatible = "maxim,max6651", + .data = (void *)4 + }, + { }, +}; +MODULE_DEVICE_TABLE(of, max6650_dt_match); + static struct max6650_data *max6650_update_device(struct device *dev) { struct max6650_data *data = dev_get_drvdata(dev); @@ -566,6 +580,17 @@ static int max6650_init_client(struct max6650_data *data, struct device *dev = &client->dev; int config; int err = -EIO; + u32 voltage; + u32 prescale; + + if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt", + &voltage)) + voltage = fan_voltage; + else + voltage = voltage > 5500000 ? 12 : 5;I think this should only accept 5V or 12V. Guenter
A 4V, 10V or 13V fan will also work just fine, the voltage register just sets the range of the feedback tachometer.
I don't have strong feelings either way, so if you feel the drive should bail out on anything but 5 or 12, that's fine with me too.
Should I change this and send a v5 patch?
+ if (of_property_read_u32(dev->of_node, "maxim,fan-prescale", + &prescale)) + prescale = prescaler; config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG); @@ -574,7 +599,7 @@ static int max6650_init_client(struct max6650_data *data, return err; } - switch (fan_voltage) { + switch (voltage) { case 0: break; case 5: @@ -584,14 +609,10 @@ static int max6650_init_client(struct max6650_data *data, config |= MAX6650_CFG_V12; break; default: - dev_err(dev, "illegal value for fan_voltage (%d)\n", - fan_voltage); + dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage); } - dev_info(dev, "Fan voltage is set to %dV.\n", - (config & MAX6650_CFG_V12) ? 12 : 5); - - switch (prescaler) { + switch (prescale) { case 0: break; case 1: @@ -614,10 +635,11 @@ static int max6650_init_client(struct max6650_data *data, | MAX6650_CFG_PRESCALER_16; break; default: - dev_err(dev, "illegal value for prescaler (%d)\n", prescaler); + dev_err(dev, "illegal value for prescaler (%d)\n", prescale); } - dev_info(dev, "Prescaler is set to %d.\n", + dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n", + (config & MAX6650_CFG_V12) ? 12 : 5, 1 << (config & MAX6650_CFG_PRESCALER_MASK)); /* @@ -651,6 +673,8 @@ static int max6650_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; + const struct of_device_id *of_id = + of_match_device(of_match_ptr(max6650_dt_match), dev); struct max6650_data *data; struct device *hwmon_dev; int err; @@ -661,7 +685,7 @@ static int max6650_probe(struct i2c_client *client, data->client = client; mutex_init(&data->update_lock); - data->nr_fans = id->driver_data; + data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data; /* * Initialize the max6650 chip @@ -691,6 +715,7 @@ MODULE_DEVICE_TABLE(i2c, max6650_id); static struct i2c_driver max6650_driver = { .driver = { .name = "max6650", + .of_match_table = of_match_ptr(max6650_dt_match), }, .probe = max6650_probe, .id_table = max6650_id,
