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Subject[PATCH 02/10] iio: imu: adis: add unlocked read/write function versions
Date
This will allow more flexible control to group reads & writes into a single
lock (particularly the state_lock).

The end-goal is to remove the indio_dev->mlock usage, and the simplest fix
would have been to just add another lock, which would not be a good idea on
the long-run.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/imu/adis.c | 34 +++++------
include/linux/iio/imu/adis.h | 114 ++++++++++++++++++++++++++++++++++-
2 files changed, 128 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 3c2d896e3a96..4f3be011c898 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -26,7 +26,14 @@
#define ADIS_MSC_CTRL_DATA_RDY_DIO2 BIT(0)
#define ADIS_GLOB_CMD_SW_RESET BIT(7)

-int adis_write_reg(struct adis *adis, unsigned int reg,
+/**
+ * __adis_write_reg() - write N bytes to register (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @value: The value to write to device (up to 4 bytes)
+ * @size: The size of the @value (in bytes)
+ */
+int __adis_write_reg(struct adis *adis, unsigned int reg,
unsigned int value, unsigned int size)
{
unsigned int page = reg / ADIS_PAGE_SIZE;
@@ -70,8 +77,6 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
},
};

- mutex_lock(&adis->state_lock);
-
spi_message_init(&msg);

if (adis->current_page != page) {
@@ -96,8 +101,7 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
adis->tx[3] = value & 0xff;
break;
default:
- ret = -EINVAL;
- goto out_unlock;
+ return -EINVAL;
}

xfers[size].cs_change = 0;
@@ -113,20 +117,18 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
adis->current_page = page;
}

-out_unlock:
- mutex_unlock(&adis->state_lock);
-
return ret;
}
-EXPORT_SYMBOL_GPL(adis_write_reg);
+EXPORT_SYMBOL_GPL(__adis_write_reg);

/**
- * adis_read_reg() - read 2 bytes from a 16-bit register
+ * __adis_read_reg() - read N bytes from register (unlocked version)
* @adis: The adis device
* @reg: The address of the lower of the two registers
* @val: The value read back from the device
+ * @size: The size of the @val buffer
*/
-int adis_read_reg(struct adis *adis, unsigned int reg,
+int __adis_read_reg(struct adis *adis, unsigned int reg,
unsigned int *val, unsigned int size)
{
unsigned int page = reg / ADIS_PAGE_SIZE;
@@ -188,15 +190,14 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
spi_message_add_tail(&xfers[3], &msg);
break;
default:
- ret = -EINVAL;
- goto out_unlock;
+ return -EINVAL;
}

ret = spi_sync(adis->spi, &msg);
if (ret) {
dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
reg, ret);
- goto out_unlock;
+ return ret;
} else {
adis->current_page = page;
}
@@ -210,12 +211,9 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
break;
}

-out_unlock:
- mutex_unlock(&adis->state_lock);
-
return ret;
}
-EXPORT_SYMBOL_GPL(adis_read_reg);
+EXPORT_SYMBOL_GPL(__adis_read_reg);

#ifdef CONFIG_DEBUG_FS

diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index 3ed5eceaac2d..3a028c40e04e 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -75,11 +75,121 @@ int adis_init(struct adis *adis, struct iio_dev *indio_dev,
struct spi_device *spi, const struct adis_data *data);
int adis_reset(struct adis *adis);

-int adis_write_reg(struct adis *adis, unsigned int reg,
+int __adis_write_reg(struct adis *adis, unsigned int reg,
unsigned int val, unsigned int size);
-int adis_read_reg(struct adis *adis, unsigned int reg,
+int __adis_read_reg(struct adis *adis, unsigned int reg,
unsigned int *val, unsigned int size);

+/**
+ * __adis_write_reg_8() - Write single byte to a register (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the register to be written
+ * @value: The value to write
+ */
+static inline int __adis_write_reg_8(struct adis *adis, unsigned int reg,
+ uint8_t val)
+{
+ return __adis_write_reg(adis, reg, val, 1);
+}
+
+/**
+ * __adis_write_reg_16() - Write 2 bytes to a pair of registers (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @value: Value to be written
+ */
+static inline int __adis_write_reg_16(struct adis *adis, unsigned int reg,
+ uint16_t val)
+{
+ return __adis_write_reg(adis, reg, val, 2);
+}
+
+/**
+ * __adis_write_reg_32() - write 4 bytes to four registers (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the lower of the four register
+ * @value: Value to be written
+ */
+static inline int __adis_write_reg_32(struct adis *adis, unsigned int reg,
+ uint32_t val)
+{
+ return __adis_write_reg(adis, reg, val, 4);
+}
+
+/**
+ * __adis_read_reg_16() - read 2 bytes from a 16-bit register (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @val: The value read back from the device
+ */
+static inline int __adis_read_reg_16(struct adis *adis, unsigned int reg,
+ uint16_t *val)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = __adis_read_reg(adis, reg, &tmp, 2);
+ *val = tmp;
+
+ return ret;
+}
+
+/**
+ * __adis_read_reg_32() - read 4 bytes from a 32-bit register (unlocked version)
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @val: The value read back from the device
+ */
+static inline int __adis_read_reg_32(struct adis *adis, unsigned int reg,
+ uint32_t *val)
+{
+ unsigned int tmp;
+ int ret;
+
+ ret = __adis_read_reg(adis, reg, &tmp, 4);
+ *val = tmp;
+
+ return ret;
+}
+
+/**
+ * adis_write_reg() - write N bytes to register
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @value: The value to write to device (up to 4 bytes)
+ * @size: The size of the @value (in bytes)
+ */
+static inline int adis_write_reg(struct adis *adis, unsigned int reg,
+ unsigned int val, unsigned int size)
+{
+ int ret;
+
+ mutex_lock(&adis->state_lock);
+ ret = __adis_write_reg(adis, reg, val, size);
+ mutex_unlock(&adis->state_lock);
+
+ return ret;
+}
+
+/**
+ * adis_read_reg() - read N bytes from register
+ * @adis: The adis device
+ * @reg: The address of the lower of the two registers
+ * @val: The value read back from the device
+ * @size: The size of the @val buffer
+ */
+static int adis_read_reg(struct adis *adis, unsigned int reg,
+ unsigned int *val, unsigned int size)
+{
+ int ret;
+
+ mutex_lock(&adis->state_lock);
+ ret = __adis_read_reg(adis, reg, val, size);
+ mutex_unlock(&adis->state_lock);
+
+ return ret;
+}
+
/**
* adis_write_reg_8() - Write single byte to a register
* @adis: The adis device
--
2.20.1
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