[PATCH v6 1/2] media: imx274: use regmap_bulk_write to write multybyte registers
From: Luca Ceresoli
Date: Wed Jul 25 2018 - 12:25:23 EST
Currently 2-bytes and 3-bytes registers are set by very similar
functions doing the needed shift & mask manipulation, followed by very
similar for loops setting one byte at a time over I2C.
Replace all of this code by a unique helper function that calls
regmap_bulk_write(), which has two advantages:
- sets all the bytes in a unique I2C transaction
- removes lots of now unused code.
Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
Changed v5 -> v6:
- fix warning on debug print on 32-bit machines (reported by the
kbuild test robot)
- fix line above 80 chars
Changed v4 -> v5:
- completely replace the former patch adding prepare_regs() by
directly calling regmap_bulk_write() (Sakari)
Changed v3 -> v4: nothing
Changed v2 -> v3:
- minor reformatting in prepare_reg() documentation
Changed v1 -> v2:
- add "media: " prefix to commit message
---
drivers/media/i2c/imx274.c | 102 ++++++++++++++-----------------------
1 file changed, 39 insertions(+), 63 deletions(-)
diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index edca63eaea9b..093c4587832a 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -690,6 +690,35 @@ static inline int imx274_write_reg(struct stimx274 *priv, u16 addr, u8 val)
return err;
}
+/**
+ * Write a multibyte register.
+ *
+ * Uses a bulk write where possible.
+ *
+ * @priv: Pointer to device structure
+ * @addr: Address of the LSB register. Other registers must be
+ * consecutive, least-to-most significant.
+ * @val: Value to be written to the register (cpu endianness)
+ * @nbytes: Number of bits to write (range: [1..3])
+ */
+static int imx274_write_mbreg(struct stimx274 *priv, u16 addr, u32 val,
+ size_t nbytes)
+{
+ __le32 val_le = cpu_to_le32(val);
+ int err;
+
+ err = regmap_bulk_write(priv->regmap, addr, &val_le, nbytes);
+ if (err)
+ dev_err(&priv->client->dev,
+ "%s : i2c bulk write failed, %x = %x (%zu bytes)\n",
+ __func__, addr, val, nbytes);
+ else
+ dev_dbg(&priv->client->dev,
+ "%s : addr 0x%x, val=0x%x (%zu bytes)\n",
+ __func__, addr, val, nbytes);
+ return err;
+}
+
/*
* Set mode registers to start stream.
* @priv: Pointer to device structure
@@ -1163,15 +1192,6 @@ static int imx274_set_digital_gain(struct stimx274 *priv, u32 dgain)
reg_val & IMX274_MASK_LSB_4_BITS);
}
-static inline void imx274_calculate_gain_regs(struct reg_8 regs[2], u16 gain)
-{
- regs->addr = IMX274_ANALOG_GAIN_ADDR_MSB;
- regs->val = (gain >> IMX274_SHIFT_8_BITS) & IMX274_MASK_LSB_3_BITS;
-
- (regs + 1)->addr = IMX274_ANALOG_GAIN_ADDR_LSB;
- (regs + 1)->val = (gain) & IMX274_MASK_LSB_8_BITS;
-}
-
/*
* imx274_set_gain - Function called when setting gain
* @priv: Pointer to device structure
@@ -1185,10 +1205,8 @@ static inline void imx274_calculate_gain_regs(struct reg_8 regs[2], u16 gain)
*/
static int imx274_set_gain(struct stimx274 *priv, struct v4l2_ctrl *ctrl)
{
- struct reg_8 reg_list[2];
int err;
u32 gain, analog_gain, digital_gain, gain_reg;
- int i;
gain = (u32)(ctrl->val);
@@ -1229,14 +1247,10 @@ static int imx274_set_gain(struct stimx274 *priv, struct v4l2_ctrl *ctrl)
if (gain_reg > IMX274_GAIN_REG_MAX)
gain_reg = IMX274_GAIN_REG_MAX;
- imx274_calculate_gain_regs(reg_list, (u16)gain_reg);
-
- for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
- err = imx274_write_reg(priv, reg_list[i].addr,
- reg_list[i].val);
- if (err)
- goto fail;
- }
+ err = imx274_write_mbreg(priv, IMX274_ANALOG_GAIN_ADDR_LSB, gain_reg,
+ 2);
+ if (err)
+ goto fail;
if (IMX274_GAIN_CONST - gain_reg == 0) {
err = -EINVAL;
@@ -1258,16 +1272,6 @@ static int imx274_set_gain(struct stimx274 *priv, struct v4l2_ctrl *ctrl)
return err;
}
-static inline void imx274_calculate_coarse_time_regs(struct reg_8 regs[2],
- u32 coarse_time)
-{
- regs->addr = IMX274_SHR_REG_MSB;
- regs->val = (coarse_time >> IMX274_SHIFT_8_BITS)
- & IMX274_MASK_LSB_8_BITS;
- (regs + 1)->addr = IMX274_SHR_REG_LSB;
- (regs + 1)->val = (coarse_time) & IMX274_MASK_LSB_8_BITS;
-}
-
/*
* imx274_set_coarse_time - Function called when setting SHR value
* @priv: Pointer to device structure
@@ -1279,10 +1283,8 @@ static inline void imx274_calculate_coarse_time_regs(struct reg_8 regs[2],
*/
static int imx274_set_coarse_time(struct stimx274 *priv, u32 *val)
{
- struct reg_8 reg_list[2];
int err;
u32 coarse_time, frame_length;
- int i;
coarse_time = *val;
@@ -1291,16 +1293,9 @@ static int imx274_set_coarse_time(struct stimx274 *priv, u32 *val)
if (err)
goto fail;
- /* prepare SHR registers */
- imx274_calculate_coarse_time_regs(reg_list, coarse_time);
-
- /* write to SHR registers */
- for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
- err = imx274_write_reg(priv, reg_list[i].addr,
- reg_list[i].val);
- if (err)
- goto fail;
- }
+ err = imx274_write_mbreg(priv, IMX274_SHR_REG_LSB, coarse_time, 2);
+ if (err)
+ goto fail;
*val = frame_length - coarse_time;
return 0;
@@ -1429,19 +1424,6 @@ static int imx274_set_test_pattern(struct stimx274 *priv, int val)
return err;
}
-static inline void imx274_calculate_frame_length_regs(struct reg_8 regs[3],
- u32 frame_length)
-{
- regs->addr = IMX274_VMAX_REG_1;
- regs->val = (frame_length >> IMX274_SHIFT_16_BITS)
- & IMX274_MASK_LSB_4_BITS;
- (regs + 1)->addr = IMX274_VMAX_REG_2;
- (regs + 1)->val = (frame_length >> IMX274_SHIFT_8_BITS)
- & IMX274_MASK_LSB_8_BITS;
- (regs + 2)->addr = IMX274_VMAX_REG_3;
- (regs + 2)->val = (frame_length) & IMX274_MASK_LSB_8_BITS;
-}
-
/*
* imx274_set_frame_length - Function called when setting frame length
* @priv: Pointer to device structure
@@ -1453,23 +1435,17 @@ static inline void imx274_calculate_frame_length_regs(struct reg_8 regs[3],
*/
static int imx274_set_frame_length(struct stimx274 *priv, u32 val)
{
- struct reg_8 reg_list[3];
int err;
u32 frame_length;
- int i;
dev_dbg(&priv->client->dev, "%s : input length = %d\n",
__func__, val);
frame_length = (u32)val;
- imx274_calculate_frame_length_regs(reg_list, frame_length);
- for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
- err = imx274_write_reg(priv, reg_list[i].addr,
- reg_list[i].val);
- if (err)
- goto fail;
- }
+ err = imx274_write_mbreg(priv, IMX274_VMAX_REG_3, frame_length, 3);
+ if (err)
+ goto fail;
return 0;
--
2.17.1