Messages in this thread Patch in this message | | | From | Tony O'Brien <> | Subject | [PATCH] hwmon: (lm75) Add a basic interrupt handler | Date | Wed, 12 Jul 2017 14:52:37 +1200 |
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The LM75 interrupt cannot be masked in the device so an over-temperature event can cause an interrupt that cannot be cleared. Add an interrupt handler if an interrupt node exists in the DTS for an LM75. The handler simply reads a device register to clear the interrupt and returns.
Signed-off-by: Tony O'Brien <tony.obrien@alliedtelesis.co.nz> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- drivers/hwmon/lm75.c | 28 ++++++++++++++++++++++++++++ drivers/hwmon/lm75.h | 1 + 2 files changed, 29 insertions(+)
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index 005ffb5ffa92..08a833e960aa 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -22,6 +22,7 @@ #include <linux/init.h> #include <linux/slab.h> #include <linux/jiffies.h> +#include <linux/interrupt.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> @@ -265,6 +266,17 @@ static void lm75_remove(void *data) i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf); } +static irqreturn_t lm75_process_interrupt(int irq, void *data) +{ + struct i2c_client *client = (struct i2c_client *)data; + int val; + + /* Do a read to clear the interrupt */ + val = i2c_smbus_read_byte_data(client, LM75_REG_CONF); + + return IRQ_HANDLED; +} + static int lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -275,6 +287,7 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) u8 set_mask, clr_mask; int new; enum lm75_type kind; + int ret; if (client->dev.of_node) kind = (enum lm75_type)of_device_get_match_data(&client->dev); @@ -375,6 +388,21 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) break; } + if (client->irq) { + /* If requesting an interrupt then set to interrupt mode */ + set_mask |= LM75_MODE_INTERRUPT; + ret = devm_request_threaded_irq(dev, client->irq, NULL, + lm75_process_interrupt, + IRQF_TRIGGER_LOW | IRQF_ONESHOT | + IRQF_SHARED, + dev_name(dev), + client); + if (ret) { + dev_err(dev, "Error requesting irq\n"); + return ret; + } + } + /* configure as specified */ status = i2c_smbus_read_byte_data(client, LM75_REG_CONF); if (status < 0) { diff --git a/drivers/hwmon/lm75.h b/drivers/hwmon/lm75.h index 5cde94e56f17..82a71d870331 100644 --- a/drivers/hwmon/lm75.h +++ b/drivers/hwmon/lm75.h @@ -31,6 +31,7 @@ #define LM75_TEMP_MIN (-55000) #define LM75_TEMP_MAX 125000 #define LM75_SHUTDOWN 0x01 +#define LM75_MODE_INTERRUPT 0x02 /* TEMP: 0.001C/bit (-55C to +125C) REG: (0.5C/bit, two's complement) << 7 */ -- 2.13.0
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