iio: accel: adxl313: make use of regmap cache

Setup regmap cache to cache register configuration, reducing bus traffic
for repeated accesses to non volatile registers.

Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Lothar Rubusch <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/accel/adxl313.h

···
 #define ADXL313_REG_BW_RATE		0x2C
 #define ADXL313_REG_POWER_CTL		0x2D
 #define ADXL313_REG_INT_MAP		0x2F
+#define ADXL313_REG_INT_SOURCE		0x30
 #define ADXL313_REG_DATA_FORMAT		0x31
 #define ADXL313_REG_DATA_AXIS(index)	(0x32 + ((index) * 2))
 #define ADXL313_REG_FIFO_CTL		0x38
···
 extern const struct regmap_access_table adxl312_writable_regs_table;
 extern const struct regmap_access_table adxl313_writable_regs_table;
 extern const struct regmap_access_table adxl314_writable_regs_table;
+
+bool adxl313_is_volatile_reg(struct device *dev, unsigned int reg);
 
 enum adxl313_device_type {
 	ADXL312,

drivers/iio/accel/adxl313_core.c

···
 };
 EXPORT_SYMBOL_NS_GPL(adxl314_readable_regs_table, "IIO_ADXL313");
 
+bool adxl313_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ADXL313_REG_DATA_AXIS(0):
+	case ADXL313_REG_DATA_AXIS(1):
+	case ADXL313_REG_DATA_AXIS(2):
+	case ADXL313_REG_DATA_AXIS(3):
+	case ADXL313_REG_DATA_AXIS(4):
+	case ADXL313_REG_DATA_AXIS(5):
+	case ADXL313_REG_FIFO_STATUS:
+	case ADXL313_REG_INT_SOURCE:
+		return true;
+	default:
+		return false;
+	}
+}
+EXPORT_SYMBOL_NS_GPL(adxl313_is_volatile_reg, "IIO_ADXL313");
+
 static int adxl312_check_id(struct device *dev,
 			    struct adxl313_data *data)
 {

drivers/iio/accel/adxl313_i2c.c

···
 		.rd_table	= &adxl312_readable_regs_table,
 		.wr_table	= &adxl312_writable_regs_table,
 		.max_register	= 0x39,
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 	[ADXL313] = {
 		.reg_bits	= 8,
···
 		.rd_table	= &adxl313_readable_regs_table,
 		.wr_table	= &adxl313_writable_regs_table,
 		.max_register	= 0x39,
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 	[ADXL314] = {
 		.reg_bits	= 8,
···
 		.rd_table	= &adxl314_readable_regs_table,
 		.wr_table	= &adxl314_writable_regs_table,
 		.max_register	= 0x39,
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 };
 

drivers/iio/accel/adxl313_spi.c

···
 		.max_register	= 0x39,
 		/* Setting bits 7 and 6 enables multiple-byte read */
 		.read_flag_mask	= BIT(7) | BIT(6),
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 	[ADXL313] = {
 		.reg_bits	= 8,
···
 		.max_register	= 0x39,
 		/* Setting bits 7 and 6 enables multiple-byte read */
 		.read_flag_mask	= BIT(7) | BIT(6),
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 	[ADXL314] = {
 		.reg_bits	= 8,
···
 		.max_register	= 0x39,
 		/* Setting bits 7 and 6 enables multiple-byte read */
 		.read_flag_mask	= BIT(7) | BIT(6),
+		.volatile_reg	= adxl313_is_volatile_reg,
+		.cache_type	= REGCACHE_MAPLE,
 	},
 };