From: Luca Ceresoli <luca@lucaceresoli.net>
To: linux-media@vger.kernel.org
Cc: Luca Ceresoli <luca@lucaceresoli.net>,
Leon Luo <leonl@leopardimaging.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 6/7] media: imx274: add helper to read multibyte registers
Date: Fri, 24 Aug 2018 18:35:24 +0200 [thread overview]
Message-ID: <20180824163525.12694-7-luca@lucaceresoli.net> (raw)
In-Reply-To: <20180824163525.12694-1-luca@lucaceresoli.net>
Currently 2-bytes and 3-bytes registers are read one byte at a time,
doing the needed shift & mask each time.
Replace all of this code by a unique helper function that calls
regmap_bulk_read(), which has two advantages:
- reads all the bytes in a unique I2C transaction
- simplifies code to read multibyte registers
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
---
drivers/media/i2c/imx274.c | 93 +++++++++++++++++++-------------------
1 file changed, 47 insertions(+), 46 deletions(-)
diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index 07bc41f537c5..783277068b45 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -659,6 +659,41 @@ static inline int imx274_write_reg(struct stimx274 *priv, u16 addr, u8 val)
return err;
}
+/**
+ * Read a multibyte register.
+ *
+ * Uses a bulk read where possible.
+ *
+ * @priv: Pointer to device structure
+ * @addr: Address of the LSB register. Other registers must be
+ * consecutive, least-to-most significant.
+ * @val: Pointer to store the register value (cpu endianness)
+ * @nbytes: Number of bytes to read (range: [1..3]).
+ * Other bytes are zet to 0.
+ *
+ * Return: 0 on success, errors otherwise
+ */
+static int imx274_read_mbreg(struct stimx274 *priv, u16 addr, u32 *val,
+ size_t nbytes)
+{
+ __le32 val_le = 0;
+ int err;
+
+ err = regmap_bulk_read(priv->regmap, addr, &val_le, nbytes);
+ if (err) {
+ dev_err(&priv->client->dev,
+ "%s : i2c bulk read failed, %x (%zu bytes)\n",
+ __func__, addr, nbytes);
+ } else {
+ *val = le32_to_cpu(val_le);
+ dev_dbg(&priv->client->dev,
+ "%s : addr 0x%x, val=0x%x (%zu bytes)\n",
+ __func__, addr, *val, nbytes);
+ }
+
+ return err;
+}
+
/**
* Write a multibyte register.
*
@@ -1377,37 +1412,17 @@ static int imx274_s_stream(struct v4l2_subdev *sd, int on)
static int imx274_get_frame_length(struct stimx274 *priv, u32 *val)
{
int err;
- u16 svr;
+ u32 svr;
u32 vmax;
- u8 reg_val[3];
- /* svr */
- err = imx274_read_reg(priv, IMX274_SVR_REG_LSB, ®_val[0]);
+ err = imx274_read_mbreg(priv, IMX274_SVR_REG_LSB, &svr, 2);
if (err)
goto fail;
- err = imx274_read_reg(priv, IMX274_SVR_REG_MSB, ®_val[1]);
+ err = imx274_read_mbreg(priv, IMX274_VMAX_REG_3, &vmax, 3);
if (err)
goto fail;
- svr = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
-
- /* vmax */
- err = imx274_read_reg(priv, IMX274_VMAX_REG_3, ®_val[0]);
- if (err)
- goto fail;
-
- err = imx274_read_reg(priv, IMX274_VMAX_REG_2, ®_val[1]);
- if (err)
- goto fail;
-
- err = imx274_read_reg(priv, IMX274_VMAX_REG_1, ®_val[2]);
- if (err)
- goto fail;
-
- vmax = ((reg_val[2] & IMX274_MASK_LSB_3_BITS) << IMX274_SHIFT_16_BITS)
- + (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
-
*val = vmax * (svr + 1);
return 0;
@@ -1588,8 +1603,7 @@ static int imx274_set_coarse_time(struct stimx274 *priv, u32 *val)
static int imx274_set_exposure(struct stimx274 *priv, int val)
{
int err;
- u16 hmax;
- u8 reg_val[2];
+ u32 hmax;
u32 coarse_time; /* exposure time in unit of line (HMAX)*/
dev_dbg(&priv->client->dev,
@@ -1597,14 +1611,10 @@ static int imx274_set_exposure(struct stimx274 *priv, int val)
/* step 1: convert input exposure_time (val) into number of 1[HMAX] */
- /* obtain HMAX value */
- err = imx274_read_reg(priv, IMX274_HMAX_REG_LSB, ®_val[0]);
- if (err)
- goto fail;
- err = imx274_read_reg(priv, IMX274_HMAX_REG_MSB, ®_val[1]);
+ err = imx274_read_mbreg(priv, IMX274_HMAX_REG_LSB, &hmax, 2);
if (err)
goto fail;
- hmax = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
+
if (hmax == 0) {
err = -EINVAL;
goto fail;
@@ -1739,9 +1749,8 @@ static int imx274_set_frame_interval(struct stimx274 *priv,
{
int err;
u32 frame_length, req_frame_rate;
- u16 svr;
- u16 hmax;
- u8 reg_val[2];
+ u32 svr;
+ u32 hmax;
dev_dbg(&priv->client->dev, "%s: input frame interval = %d / %d",
__func__, frame_interval.numerator,
@@ -1769,25 +1778,17 @@ static int imx274_set_frame_interval(struct stimx274 *priv,
* frame_length (i.e. VMAX) = (frame_interval) x 72M /(SVR+1) / HMAX
*/
- /* SVR */
- err = imx274_read_reg(priv, IMX274_SVR_REG_LSB, ®_val[0]);
+ err = imx274_read_mbreg(priv, IMX274_SVR_REG_LSB, &svr, 2);
if (err)
goto fail;
- err = imx274_read_reg(priv, IMX274_SVR_REG_MSB, ®_val[1]);
- if (err)
- goto fail;
- svr = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
+
dev_dbg(&priv->client->dev,
"%s : register SVR = %d\n", __func__, svr);
- /* HMAX */
- err = imx274_read_reg(priv, IMX274_HMAX_REG_LSB, ®_val[0]);
+ err = imx274_read_mbreg(priv, IMX274_HMAX_REG_LSB, &hmax, 2);
if (err)
goto fail;
- err = imx274_read_reg(priv, IMX274_HMAX_REG_MSB, ®_val[1]);
- if (err)
- goto fail;
- hmax = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
+
dev_dbg(&priv->client->dev,
"%s : register HMAX = %d\n", __func__, hmax);
--
2.17.1
next prev parent reply other threads:[~2018-08-24 16:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-24 16:35 [PATCH 0/7] media: imx274: miscellaneous improvements Luca Ceresoli
2018-08-24 16:35 ` [PATCH 1/7] media: imx274: rename IMX274_DEFAULT_MODE to IMX274_DEFAULT_BINNING Luca Ceresoli
2018-08-24 16:35 ` [PATCH 2/7] media: imx274: rearrange sensor startup register tables Luca Ceresoli
2018-08-24 16:35 ` [PATCH 3/7] media: imx274: don't hard-code the subdev name to DRIVER_NAME Luca Ceresoli
2018-08-25 14:49 ` Sakari Ailus
2018-08-26 20:41 ` Luca Ceresoli
2018-08-28 8:11 ` Philippe De Muyter
2018-08-28 9:22 ` Hans Verkuil
2018-08-28 16:02 ` Philippe De Muyter
2018-08-29 11:07 ` Sakari Ailus
2018-08-29 11:29 ` Philippe De Muyter
2018-08-29 11:38 ` Sakari Ailus
2018-08-29 21:23 ` Laurent Pinchart
2018-08-30 6:58 ` Philippe De Muyter
2018-08-30 9:33 ` Sakari Ailus
2018-08-24 16:35 ` [PATCH 4/7] media: imx274: rename frmfmt and format to "mode" Luca Ceresoli
2018-08-24 16:35 ` [PATCH 5/7] media: imx274: fix error in function docs Luca Ceresoli
2018-08-24 16:35 ` Luca Ceresoli [this message]
2018-08-24 16:35 ` [PATCH 7/7] media: imx274: switch to SPDX license identifier Luca Ceresoli
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