Hi Sylwester,


Thanks for the thorough review.


On 06/27/2013 05:57 PM, Sylwester Nawrocki wrote:

Hi Andrzej,

On 06/05/2013 01:44 PM, Andrzej Hajda wrote:

quoted

Driver for Samsung S5K5BAF UXGA 1/5" 2M CMOS Image Sensor
with embedded SoC ISP.
The driver exposes the sensor as two V4L2 subdevices:
- S5K5BAF-CIS - pure CMOS Image Sensor, fixed 1600x1200 format,
  no controls.
- S5K5BAF-ISP - Image Signal Processor, formats up to 1600x1200,
  pre/post ISP cropping, downscaling via selection API, controls.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Andrzej Hajda <redacted>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
v3:
- narrowed state->error usage to i2c and power errors,

Hmm, there still seems to be quite a few functions that use state->error
and IMHO it would be better if those just return the result directly.
How about changing at least these:

static void s5k5baf_check_fw_revision(struct s5k5baf *state)
static void s5k5baf_hw_set_video_bus(struct s5k5baf *state)
static void s5k5baf_power_on(struct s5k5baf *state)
static void s5k5baf_power_off(struct s5k5baf *state)
static void s5k5baf_hw_set_crop_rects(struct s5k5baf *state)

to return result directly ?

I see no good reason in complicating those functions and their callers,
beside positive review :) OK I see some reasons, but it still does not
convince me.

Maybe I should present the idea of state->error 'pattern' in separate RFC
to attract broader audience and eventually get public acceptance or
eternal damnation :)

Anyway I will convert those functions to the 'classic' form in next
patch version,
but my heart is bleeding :)

Personally I would also convert functins used in s5k5baf_s_ctrl()
handler:
	s5k5baf_hw_set_awb()
	s5k5baf_hw_set_colorfx()
	s5k5baf_hw_set_auto_exposure()
	s5k5baf_hw_set_mirror()
	s5k5baf_hw_set_anti_flicker()
	s5k5baf_hw_set_test_pattern()

And have state->err cleared at beginning of s5k5baf_s_ctrl().
But I'll probably not complain if those are left as they are. :)

quoted

- private gain controls replaced by red/blue balance user controls,
- added checks to devicetree gpio node parsing

v2:
- lower-cased driver name,
- removed underscore from regulator names,
- removed platform data code,
- v4l controls grouped in anonymous structs,
- added s5k5baf_clear_error function,
- private controls definitions moved to uapi header file,
- added v4l2-controls.h reservation for private controls,
- corrected subdev registered/unregistered code,
- .log_status sudbev op set to v4l2 helper,
- moved entity link creation to probe routines,
- added cleanup on error to probe function.
---
 .../devicetree/bindings/media/samsung-s5k5baf.txt  |   53 +
 MAINTAINERS                                        |    7 +
 drivers/media/i2c/Kconfig                          |    7 +
 drivers/media/i2c/Makefile                         |    1 +
 drivers/media/i2c/s5k5baf.c                        | 1979 ++++++++++++++++++++
 5 files changed, 2047 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/samsung-s5k5baf.txt
 create mode 100644 drivers/media/i2c/s5k5baf.c

diff --git a/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt 

b/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt
new file mode 100644
index 0000000..0e46743

--- /dev/null
+++ b/Documentation/devicetree/bindings/media/samsung-s5k5baf.txt

@@ -0,0 +1,53 @@
+Samsung S5K5BAF UXGA 1/5" 2M CMOS Image Sensor with embedded SoC ISP
+-------------------------------------------------------------
+
+Required properties:
+
+- compatible	  : "samsung,s5k5baf";
+- reg		  : i2c slave address of the sensor;

i2c should be capitalized.

OK

[...]

quoted

+/* Auto-algorithms enable mask */
+#define REG_DBG_AUTOALG_EN		0x03f8
+#define  AALG_ALL_EN			BIT(0)
+#define  AALG_AE_EN			BIT(1)
+#define  AALG_DIVLEI_EN			BIT(2)
+#define  AALG_WB_EN			BIT(3)
+#define  AALG_USE_WB_FOR_ISP		BIT(4)
+#define  AALG_FLICKER_EN		BIT(5)
+#define  AALG_FIT_EN			BIT(6)
+#define  AALG_WRHW_EN			BIT(7)

Perhaps some comment on what the below definitions refer to ?

OK

quoted

+#define REG_PTR_CCM_HORIZON		0x06d0
+#define REG_PTR_CCM_INCANDESCENT	0x06d4
+#define REG_PTR_CCM_WARM_WHITE		0x06d8
+#define REG_PTR_CCM_COOL_WHITE		0x06dc
+#define REG_PTR_CCM_DL50		0x06e0
+#define REG_PTR_CCM_DL65		0x06e4
+#define REG_PTR_CCM_OUTDOOR		0x06ec
+
+#define REG_ARR_CCM(n)			(0x2800 + 36 * (n))
+

[...]

quoted

+struct s5k5baf_ctrls {
+	struct v4l2_ctrl_handler handler;
+	struct { /* Auto / manual white balance cluster */
+		struct v4l2_ctrl *awb;
+		struct v4l2_ctrl *gain_red;
+		struct v4l2_ctrl *gain_blue;
+	};
+	struct { /* Mirror cluster */
+		struct v4l2_ctrl *hflip;
+		struct v4l2_ctrl *vflip;
+	};
+	struct { /* Auto exposure / manual exposure and gain cluster */
+		struct v4l2_ctrl *auto_exp;
+		struct v4l2_ctrl *exposure;
+		struct v4l2_ctrl *gain;
+	};
+};
+
+struct s5k5baf {
+	u32 mclk_frequency;
+	struct s5k5baf_gpio gpios[2];

	struct s5k5baf_gpio gpios[GPIO_NUM]; ?

OK

quoted

+	enum v4l2_mbus_type bus_type;
+	u8 nlanes;
+	u8 hflip:1;
+	u8 vflip:1;

I would just make these 2 fields u8, no need to complicate it with
bitfields.

OK

quoted

+	struct regulator_bulk_data supplies[S5K5BAF_NUM_SUPPLIES];
+
+	struct v4l2_subdev cis_sd;
+	struct media_pad cis_pad;
+
+	struct v4l2_subdev sd;
+	struct media_pad pads[2];
+
+	/* protects the struct members below */
+	struct mutex lock;
+
+	int error;
+
+	struct v4l2_rect crop_sink;
+	struct v4l2_rect compose;
+	struct v4l2_rect crop_source;
+	/* index to s5k5baf_formats array */
+	int pixfmt;
+	/* actual frame interval in 100us */
+	u16 fiv;
+	/* requested frame interval in 100us */
+	u16 req_fiv;
+
+	struct s5k5baf_ctrls ctrls;
+
+	unsigned int streaming:1;
+	unsigned int apply_cfg:1;
+	unsigned int apply_crop:1;
+	unsigned int power;
+};
+
+static const struct s5k5baf_pixfmt s5k5baf_formats[] = {
+	{ V4L2_MBUS_FMT_VYUY8_2X8,	V4L2_COLORSPACE_JPEG,	5 },
+	/* range 16-240 */
+	{ V4L2_MBUS_FMT_VYUY8_2X8,	V4L2_COLORSPACE_REC709,	6 },
+	{ V4L2_MBUS_FMT_RGB565_2X8_BE,	V4L2_COLORSPACE_JPEG,	0 },
+};
+
+static struct v4l2_rect s5k5baf_cis_rect = { 0, 0, S5K5BAF_CIS_WIDTH,
+				     S5K5BAF_CIS_HEIGHT };
+static struct v4l2_rect s5k5baf_def_rect = { 0, 0, S5K5BAF_OUT_WIDTH_DEF,
+				     S5K5BAF_OUT_HEIGHT_DEF };
+
+static inline struct v4l2_subdev *ctrl_to_sd(struct v4l2_ctrl *ctrl)
+{
+	return &container_of(ctrl->handler, struct s5k5baf, ctrls.handler)->sd;
+}
+
+static inline bool s5k5baf_is_cis_subdev(struct v4l2_subdev *sd)
+{
+	return sd->entity.type == MEDIA_ENT_T_V4L2_SUBDEV_SENSOR;
+}
+
+static inline struct s5k5baf *to_s5k5baf(struct v4l2_subdev *sd)
+{
+	if (s5k5baf_is_cis_subdev(sd))
+		return container_of(sd, struct s5k5baf, cis_sd);
+	else
+		return container_of(sd, struct s5k5baf, sd);
+}
+
+static u16 s5k5baf_i2c_read(struct s5k5baf *state, u16 addr)
+{
+	struct i2c_client *c = v4l2_get_subdevdata(&state->sd);
+	u16 w, r;
+	struct i2c_msg msg[] = {
+		{.addr = c->addr, .flags = 0, .len = 2, .buf = (u8 *)&w},
+		{.addr = c->addr, .flags = I2C_M_RD, .len = 2, .buf = (u8 *)&r},
+	};
+	int ret;
+
+	if (state->error)
+		return 0;
+
+	w = htons(addr);
+	ret = i2c_transfer(c->adapter, msg, 2);
+	r = ntohs(r);
+
+	v4l2_dbg(3, debug, c, "i2c_read: 0x%04x : 0x%04x\n", addr, r);
+
+	if (ret != 2) {
+		v4l2_err(c, "i2c_read: error during transfer (%d)\n", ret);
+		state->error = ret;
+	}
+	return r;
+}
+
+static void s5k5baf_i2c_write(struct s5k5baf *state, u16 addr, u16 val)
+{
+	u8 buf[4] = { addr >> 8, addr & 0xFF, val >> 8, val & 0xFF };
+	struct i2c_client *c = v4l2_get_subdevdata(&state->sd);
+	int ret;
+
+	if (state->error)
+		return;
+
+	ret = i2c_master_send(c, buf, 4);
+	v4l2_dbg(3, debug, c, "i2c_write: 0x%04x : 0x%04x\n", addr, val);
+
+	if (ret != 4) {
+		v4l2_err(c, "i2c_write: error during transfer (%d)\n", ret);
+		state->error = ret;
+	}
+}
+
+static u16 s5k5baf_read(struct s5k5baf *state, u16 addr)
+{
+	s5k5baf_i2c_write(state, REG_CMDRD_ADDR, addr);
+	return s5k5baf_i2c_read(state, REG_CMD_BUF);
+}
+
+static void s5k5baf_write(struct s5k5baf *state, u16 addr, u16 val)
+{
+	s5k5baf_i2c_write(state, REG_CMDWR_ADDR, addr);
+	s5k5baf_i2c_write(state, REG_CMD_BUF, val);
+}
+
+static void s5k5baf_write_arr_seq(struct s5k5baf *state, u16 addr,
+				  u16 count, const u16 *seq)
+{
+	struct i2c_client *c = v4l2_get_subdevdata(&state->sd);
+	u16 buf[count + 1];
+	int ret, n;
+
+	s5k5baf_i2c_write(state, REG_CMDWR_ADDR, addr);
+	if (state->error)
+		return;
+
+	buf[0] = __constant_htons(REG_CMD_BUF);
+	for (n = 1; n <= count; ++n)
+		buf[n] = htons(*seq++);
+
+	n *= 2;
+	ret = i2c_master_send(c, (char *)buf, n);
+	v4l2_dbg(3, debug, c, "i2c_write_seq(count=%d): %*ph\n", count,
+		 min(2 * count, 64), seq - count);
+
+	if (ret != n) {
+		v4l2_err(c, "i2c_write_seq: error during transfer (%d)\n", ret);
+		state->error = ret;
+	}
+}
+
+#define s5k5baf_write_seq(state, addr, seq...) \
+	s5k5baf_write_arr_seq(state, addr, sizeof((char[]){ seq }), \
+			      (const u16 []){ seq });
+
+/* add items count at the beginning of the list */
+#define NSEQ(seq...) sizeof((char[]){ seq }), seq
+
+/*
+ * s5k5baf_write_nseq() - Writes sequences of values to sensor memory via i2c
+ * @nseq: sequence of u16 words in format:
+ *	(N, address, value[1]...value[N-1])*,0
+ * Ex.:
+ *	u16 seq[] = { NSEQ(0x4000, 1, 1), NSEQ(0x4010, 640, 480), 0 };
+ *	ret = s5k5baf_write_nseq(c, seq);
+ */
+static void s5k5baf_write_nseq(struct s5k5baf *state, const u16 *nseq)
+{
+	int count;
+
+	while ((count = *nseq++)) {
+		u16 addr = *nseq++;
+		--count;
+
+		s5k5baf_write_arr_seq(state, addr, count, nseq);
+		nseq += count;
+	}
+}
+
+static void s5k5baf_synchronize(struct s5k5baf *state, int timeout, u16 addr)
+{
+	unsigned long end = jiffies + msecs_to_jiffies(timeout);
+	u16 reg;
+
+	s5k5baf_write(state, addr, 1);
+	do {
+		reg = s5k5baf_read(state, addr);
+		if (state->error || !reg)
+			return;
+		usleep_range(5000, 10000);
+	} while (time_is_after_jiffies(end));
+
+	v4l2_err(&state->sd, "timeout on register synchronize (%#x)\n", addr);
+	state->error = -ETIMEDOUT;
+}
+
+static void s5k5baf_hw_patch(struct s5k5baf *state)
+{
+	static const u16 nseq_patch[] = {
+		NSEQ(0x1668,
+		0xb5fe, 0x0007, 0x683c, 0x687e, 0x1da5, 0x88a0, 0x2800, 0xd00b,

[...]

quoted

+		0x0058, 0x0000),
+		0
+	};
+
+	s5k5baf_write_nseq(state, nseq_patch);
+}
+
+static void s5k5baf_hw_set_clocks(struct s5k5baf *state)
+{
+	unsigned long mclk = state->mclk_frequency / 1000;
+	u16 status;
+	static const u16 nseq_clk_cfg[] = {
+		NSEQ(REG_I_USE_NPVI_CLOCKS,
+		  NPVI_CLOCKS, NMIPI_CLOCKS, 0,
+		  SCLK_PVI_FREQ / 4, PCLK_MIN_FREQ / 4, PCLK_MAX_FREQ / 4,
+		  SCLK_MIPI_FREQ / 4, PCLK_MIN_FREQ / 4, PCLK_MAX_FREQ / 4),
+		NSEQ(REG_I_USE_REGS_API, 1),
+		0
+	};
+
+	s5k5baf_write_seq(state, REG_I_INCLK_FREQ_L, mclk & 0xffff, mclk >> 16);
+	s5k5baf_write_nseq(state, nseq_clk_cfg);
+
+	s5k5baf_synchronize(state, 250, REG_I_INIT_PARAMS_UPDATED);
+	status = s5k5baf_read(state, REG_I_ERROR_INFO);
+	if (!state->error && status) {
+		v4l2_err(&state->sd, "error configuring PLL (%d)\n", status);
+		state->error = -EINVAL;
+	}
+}
+
+static void s5k5baf_hw_set_ccm(struct s5k5baf *state)
+{
+	static const u16 nseq_cfg[] = {
+		NSEQ(REG_PTR_CCM_HORIZON,

[...]

quoted

+		0
+	};
+	s5k5baf_write_nseq(state, nseq_cfg);
+}
+
+static void s5k5baf_hw_set_cis(struct s5k5baf *state)
+{
+	static const u16 nseq_cfg[] = {
+		NSEQ(0xc202, 0x0700),

[...]

quoted

+		0
+	};
+
+	s5k5baf_i2c_write(state, REG_CMDWR_PAGE, PAGE_IF_HW);
+	s5k5baf_write_nseq(state, nseq_cfg);
+	s5k5baf_i2c_write(state, REG_CMDWR_PAGE, PAGE_IF_SW);
+}
+
+static void s5k5baf_hw_sync_cfg(struct s5k5baf *state)
+{
+	s5k5baf_write(state, REG_G_PREV_CFG_CHG, 1);
+	if (state->apply_crop) {
+		s5k5baf_write(state, REG_G_INPUTS_CHANGE_REQ, 1);
+		s5k5baf_write(state, REG_G_PREV_CFG_BYPASS_CHANGED, 1);
+	}
+	s5k5baf_synchronize(state, 500, REG_G_NEW_CFG_SYNC);
+
+}
+/* Set horizontal and vertical image flipping */
+static void s5k5baf_hw_set_mirror(struct s5k5baf *state, int horiz_flip)
+{
+	u16 vflip = state->ctrls.vflip->val ^ state->vflip;
+	u16 flip = (horiz_flip ^ state->hflip) | (vflip << 1);
+
+	s5k5baf_write(state, REG_P_PREV_MIRROR(0), flip);
+	if (state->streaming)
+		s5k5baf_hw_sync_cfg(state);
+}
+
+/* Configure auto/manual white balance and R/G/B gains */
+static void s5k5baf_hw_set_awb(struct s5k5baf *state, int awb)
+{
+	struct s5k5baf_ctrls *ctrls = &state->ctrls;
+	u16 reg;
+
+	reg = s5k5baf_read(state, REG_DBG_AUTOALG_EN);
+
+	if (!awb)
+		s5k5baf_write_seq(state, REG_SF_RGAIN,
+				  ctrls->gain_red->val, 1,
+				  S5K5BAF_GAIN_GREEN_DEF, 1,
+				  ctrls->gain_blue->val, 1,
+				  1);
+	reg = awb ? reg | AALG_WB_EN : reg & ~AALG_WB_EN;
+	s5k5baf_write(state, REG_DBG_AUTOALG_EN, reg);
+}
+
+/* Program FW with exposure time, 'exposure' in us units */
+static void s5k5baf_hw_set_user_exposure(struct s5k5baf *state, int exposure)
+{
+	unsigned int time = exposure / 10;
+
+	s5k5baf_write_seq(state, REG_SF_USR_EXPOSURE_L,
+			  time & 0xffff, time >> 16, 1);
+}
+
+static void s5k5baf_hw_set_user_gain(struct s5k5baf *state, int gain)
+{
+	s5k5baf_write_seq(state, REG_SF_USR_TOT_GAIN, gain, 1);
+}
+
+/* Set auto/manual exposure and total gain */
+static void s5k5baf_hw_set_auto_exposure(struct s5k5baf *state, int value)
+{
+	unsigned int exp_time = state->ctrls.exposure->val;
+	u16 auto_alg;
+
+	auto_alg = s5k5baf_read(state, REG_DBG_AUTOALG_EN);
+
+	if (value == V4L2_EXPOSURE_AUTO) {
+		auto_alg |= AALG_AE_EN | AALG_DIVLEI_EN;
+	} else {
+		s5k5baf_hw_set_user_exposure(state, exp_time);
+		s5k5baf_hw_set_user_gain(state, state->ctrls.gain->val);
+		auto_alg &= ~(AALG_AE_EN | AALG_DIVLEI_EN);
+	}
+
+	s5k5baf_write(state, REG_DBG_AUTOALG_EN, auto_alg);
+}
+
+static void s5k5baf_hw_set_anti_flicker(struct s5k5baf *state, int v)
+{
+	u16 auto_alg;
+
+	auto_alg = s5k5baf_read(state, REG_DBG_AUTOALG_EN);
+
+	if (v == V4L2_CID_POWER_LINE_FREQUENCY_AUTO) {
+		auto_alg |= AALG_FLICKER_EN;
+	} else {
+		auto_alg &= ~AALG_FLICKER_EN;
+		/* The V4L2_CID_LINE_FREQUENCY control values match
+		 * the register values */
+		s5k5baf_write_seq(state, REG_SF_FLICKER_QUANT, v, 1);
+	}
+
+	s5k5baf_write(state, REG_DBG_AUTOALG_EN, auto_alg);
+}
+
+static void s5k5baf_hw_set_colorfx(struct s5k5baf *state, int val)
+{
+	static const u16 colorfx[] = {
+		[V4L2_COLORFX_NONE] = 0,
+		[V4L2_COLORFX_BW] = 1,
+		[V4L2_COLORFX_NEGATIVE] = 2,
+		[V4L2_COLORFX_SEPIA] = 3,
+		[V4L2_COLORFX_SKY_BLUE] = 4,
+		[V4L2_COLORFX_SKETCH] = 5,
+	};
+
+	if (val >= ARRAY_SIZE(colorfx)) {
+		v4l2_err(&state->sd, "colorfx(%d) out of range(%d)\n",
+			 val, ARRAY_SIZE(colorfx));
+		state->error = -EINVAL;
+	} else {
+		s5k5baf_write(state, REG_G_SPEC_EFFECTS, colorfx[val]);
+	}
+}
+
+static int s5k5baf_find_pixfmt(struct v4l2_mbus_framefmt *mf)
+{
+	int i, c = -1;
+
+	for (i = 0; i < ARRAY_SIZE(s5k5baf_formats); i++) {
+		if (mf->colorspace != s5k5baf_formats[i].colorspace)
+			continue;
+		if (mf->code == s5k5baf_formats[i].code)
+			return i;
+		if (c < 0)
+			c = i;
+	}
+	return (c < 0) ? 0 : c;
+}
+
+static void s5k5baf_hw_set_video_bus(struct s5k5baf *state)
+{
+	u16 en_packets;
+
+	switch (state->bus_type) {
+	case V4L2_MBUS_CSI2:
+		en_packets = EN_PACKETS_CSI2;
+		break;
+	case V4L2_MBUS_PARALLEL:
+		en_packets = 0;
+		break;
+	default:
+		v4l2_err(&state->sd, "unknown video bus: %d\n", state->bus_type);
+		state->error = -EINVAL;
+		return;
+	};
+
+	s5k5baf_write_seq(state, REG_OIF_EN_MIPI_LANES,
+			  state->nlanes, en_packets, 1);
+}
+
+static u16 s5k5baf_get_cfg_error(struct s5k5baf *state)
+{
+	u16 err = s5k5baf_read(state, REG_G_PREV_CFG_ERROR);
+	if (err)
+		s5k5baf_write(state, REG_G_PREV_CFG_ERROR, 0);
+	return err;
+}
+
+static void s5k5baf_hw_set_fiv(struct s5k5baf *state, u16 fiv)
+{
+	s5k5baf_write(state, REG_P_MAX_FR_TIME(0), fiv);
+	s5k5baf_hw_sync_cfg(state);
+}
+
+static void s5k5baf_hw_find_min_fiv(struct s5k5baf *state)
+{
+	u16 err, fiv;
+	int n;
+
+	fiv = s5k5baf_read(state,  REG_G_ACTUAL_P_FR_TIME);
+	if (state->error)
+		return;
+
+	for (n = 5; n > 0; --n) {
+		s5k5baf_hw_set_fiv(state, fiv);
+		err = s5k5baf_get_cfg_error(state);
+		if (state->error)
+			return;
+		switch (err) {
+		case CFG_ERROR_RANGE:
+			++fiv;
+			break;
+		case 0:
+			state->fiv = fiv;
+			v4l2_info(&state->sd,
+				  "found valid frame interval: %d00us\n", fiv);
+			return;
+		default:
+			v4l2_err(&state->sd,
+				 "error setting frame interval: %d\n", err);
+			state->error = -EINVAL;
+		}
+	};
+	v4l2_err(&state->sd, "cannot find correct frame interval\n");
+	state->error = -ERANGE;
+}
+
+static void s5k5baf_hw_validate_cfg(struct s5k5baf *state)
+{
+	u16 err;
+
+	err = s5k5baf_get_cfg_error(state);
+	if (state->error)
+		return;
+
+	switch (err) {
+	case 0:
+		state->apply_cfg = 1;
+		return;
+	case CFG_ERROR_RANGE:
+		s5k5baf_hw_find_min_fiv(state);
+		if (!state->error)
+			state->apply_cfg = 1;
+		return;
+	default:
+		v4l2_err(&state->sd,
+			 "error setting format: %d\n", err);
+		state->error = -EINVAL;
+	}
+}
+
+static void s5k5baf_rescale(struct v4l2_rect *r, const struct v4l2_rect *v,
+			    const struct v4l2_rect *n,
+			    const struct v4l2_rect *d)
+{
+	r->left = v->left * n->width / d->width;
+	r->top = v->top * n->height / d->height;
+	r->width = v->width * n->width / d->width;
+	r->height = v->height * n->height / d->height;
+}
+
+static void s5k5baf_hw_set_crop_rects(struct s5k5baf *state)
+{
+	struct v4l2_rect *p, r;
+	u16 err;
+
+	p = &state->crop_sink;
+	s5k5baf_write_seq(state, REG_G_PREVREQ_IN_WIDTH, p->width, p->height,
+			  p->left, p->top);
+
+	s5k5baf_rescale(&r, &state->crop_source, &state->crop_sink,
+			&state->compose);
+	s5k5baf_write_seq(state, REG_G_PREVZOOM_IN_WIDTH, r.width, r.height,
+			  r.left, r.top);
+
+	s5k5baf_synchronize(state, 500, REG_G_INPUTS_CHANGE_REQ);
+	s5k5baf_synchronize(state, 500, REG_G_PREV_CFG_BYPASS_CHANGED);
+	err = s5k5baf_get_cfg_error(state);
+	if (state->error)
+		return;
+
+	switch (err) {
+	case 0:
+		break;
+	case CFG_ERROR_RANGE:
+		/* retry crop with frame interval set to max */
+		s5k5baf_hw_set_fiv(state, S5K5BAF_MAX_FR_TIME);
+		err = s5k5baf_get_cfg_error(state);
+		if (state->error)
+			return;
+		if (err) {
+			v4l2_err(&state->sd,
+				 "crop error on max frame interval: %d\n", err);
+			state->error = -EINVAL;
+		}
+		s5k5baf_hw_set_fiv(state, state->req_fiv);
+		s5k5baf_hw_validate_cfg(state);
+		break;
+	default:
+		v4l2_err(&state->sd, "crop error: %d\n", err);
+		state->error = -EINVAL;
+		return;
+	}
+
+	if (!state->apply_cfg)
+		return;
+
+	p = &state->crop_source;
+	s5k5baf_write_seq(state, REG_P_OUT_WIDTH(0), p->width, p->height);
+	s5k5baf_hw_set_fiv(state, state->req_fiv);
+	s5k5baf_hw_validate_cfg(state);
+}
+
+static void s5k5baf_hw_set_config(struct s5k5baf *state)
+{
+	u16 reg_fmt = s5k5baf_formats[state->pixfmt].reg_p_fmt;
+	struct v4l2_rect *r = &state->crop_source;
+
+	s5k5baf_write_seq(state, REG_P_OUT_WIDTH(0),
+			  r->width, r->height, reg_fmt,
+			  PCLK_MAX_FREQ >> 2, PCLK_MIN_FREQ >> 2,
+			  PVI_MASK_MIPI, CLK_MIPI_INDEX,
+			  FR_RATE_FIXED, FR_RATE_Q_DYNAMIC,
+			  state->req_fiv, S5K5BAF_MIN_FR_TIME);
+	s5k5baf_hw_sync_cfg(state);
+	s5k5baf_hw_validate_cfg(state);
+}
+
+
+static void s5k5baf_hw_set_test_pattern(struct s5k5baf *state, int id)
+{
+	s5k5baf_i2c_write(state, REG_PATTERN_WIDTH, 800);
+	s5k5baf_i2c_write(state, REG_PATTERN_HEIGHT, 511);
+	s5k5baf_i2c_write(state, REG_PATTERN_PARAM, 0);
+	s5k5baf_i2c_write(state, REG_PATTERN_SET, id);
+}

[...]

quoted

+static void s5k5baf_power_on(struct s5k5baf *state)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(S5K5BAF_NUM_SUPPLIES, state->supplies);
+	if (ret) {
+		state->error = ret;
+		return;
+	}
+
+	s5k5baf_gpio_deassert(state, STBY);
+	usleep_range(50, 100);
+	s5k5baf_gpio_deassert(state, RST);
+}
+
+static void s5k5baf_power_off(struct s5k5baf *state)
+{
+	int ret;
+
+	state->streaming = 0;
+	state->apply_cfg = 0;
+	state->apply_crop = 0;
+	s5k5baf_gpio_assert(state, RST);
+	s5k5baf_gpio_assert(state, STBY);
+	ret = regulator_bulk_disable(S5K5BAF_NUM_SUPPLIES, state->supplies);
+	if (ret && !state->error)
+		state->error = ret;
+}
+
+static void s5k5baf_hw_init(struct s5k5baf *state)
+{
+	s5k5baf_i2c_write(state, AHB_MSB_ADDR_PTR, PAGE_IF_HW);
+	s5k5baf_i2c_write(state, REG_CLEAR_HOST_INT, 0);
+	s5k5baf_i2c_write(state, REG_SW_LOAD_COMPLETE, 1);
+	s5k5baf_i2c_write(state, REG_CMDRD_PAGE, PAGE_IF_SW);
+	s5k5baf_i2c_write(state, REG_CMDWR_PAGE, PAGE_IF_SW);
+}
+
+static int s5k5baf_clear_error(struct s5k5baf *state)
+{
+	int ret = state->error;
+
+	state->error = 0;
+	return ret;
+}
+
+/*
+ * V4L2 subdev core and video operations
+ */
+
+static void s5k5baf_initialize_data(struct s5k5baf *state)
+{
+	state->crop_sink = s5k5baf_cis_rect;
+	state->compose = s5k5baf_def_rect;
+	state->crop_source = state->compose;
+	state->pixfmt = 0;
+	state->req_fiv = 10000 / 15;
+	state->fiv = state->req_fiv;
+}
+
+static int s5k5baf_set_power(struct v4l2_subdev *sd, int on)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+	int ret;
+
+	mutex_lock(&state->lock);
+
+	if (!on == state->power) {
+		if (on) {
+			s5k5baf_initialize_data(state);
+			s5k5baf_power_on(state);
+			s5k5baf_hw_init(state);
+			s5k5baf_hw_patch(state);
+			s5k5baf_i2c_write(state, REG_SET_HOST_INT, 1);
+			s5k5baf_hw_set_clocks(state);
+			s5k5baf_hw_set_video_bus(state);
+			s5k5baf_hw_set_cis(state);
+			s5k5baf_hw_set_ccm(state);
+		} else {
+			s5k5baf_power_off(state);
+		}
+
+		if (!state->error)
+			state->power += on ? 1 : -1;
+	}
+
+	ret = s5k5baf_clear_error(state);
+	mutex_unlock(&state->lock);
+
+	if (!ret && on && state->power == 1)
+		ret = v4l2_ctrl_handler_setup(&state->ctrls.handler);
+
+	return ret;
+}
+
+static void s5k5baf_hw_set_stream(struct s5k5baf *state, int enable)
+{
+	s5k5baf_write_seq(state, REG_G_ENABLE_PREV, enable, 1);
+}
+
+static int s5k5baf_s_stream(struct v4l2_subdev *sd, int on)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+	int ret;
+
+	if (state->streaming == !!on)
+		return 0;
+
+	mutex_lock(&state->lock);
+
+	if (!on) {
+		s5k5baf_hw_set_stream(state, 0);
+		goto out;
+	}
+
+	s5k5baf_hw_set_config(state);
+	s5k5baf_hw_set_stream(state, 1);
+	s5k5baf_i2c_write(state, 0xb0cc, 0x000b);
+
+	if (!state->error)
+		state->streaming = 1;

state->streaming seems to never be cleared in this callback, only
on power off.

How about rewriting it as:

	if (!on) {
		s5k5baf_hw_set_config(state);
		s5k5baf_hw_set_stream(state, 1);
		s5k5baf_i2c_write(state, 0xb0cc, 0x000b);
	} else {
		s5k5baf_hw_set_stream(state, 0);
	}
	if (!state->error)
		state->streaming = 1;

without an ugly as hell 'goto' ? :-)

OK

quoted

+
+out:
+	ret = s5k5baf_clear_error(state);
+	mutex_unlock(&state->lock);
+
+	return ret;
+}
+
+static int s5k5baf_g_frame_interval(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_frame_interval *fi)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+
+	mutex_lock(&state->lock);
+	fi->interval.numerator = state->fiv;
+	fi->interval.denominator = 10000;
+	mutex_unlock(&state->lock);
+
+	return 0;
+}
+
+static void s5k5baf_set_frame_interval(struct s5k5baf *state,
+				       struct v4l2_subdev_frame_interval *fi)
+{
+	struct v4l2_fract *i = &fi->interval;
+
+	if (fi->interval.denominator == 0)
+		state->req_fiv = S5K5BAF_MAX_FR_TIME;
+	else
+		state->req_fiv = clamp_t(u32,
+					 i->numerator * 10000 / i->denominator,
+					 S5K5BAF_MIN_FR_TIME,
+					 S5K5BAF_MAX_FR_TIME);
+
+	state->fiv = state->req_fiv;
+	if (state->apply_cfg) {
+		s5k5baf_hw_set_fiv(state, state->req_fiv);
+		s5k5baf_hw_validate_cfg(state);
+	}
+	*i = (struct v4l2_fract){state->fiv, 10000};

I find it more readable with spaces inside {}

	*i = (struct v4l2_fract){ state->fiv, 10000 };

OK

quoted

+	if (state->fiv == state->req_fiv)
+		v4l2_info(&state->sd, "frame interval changed to %d00us\n",
+			  state->fiv);
+}
+
+static int s5k5baf_s_frame_interval(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_frame_interval *fi)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+
+	mutex_lock(&state->lock);
+	s5k5baf_set_frame_interval(state, fi);
+	mutex_unlock(&state->lock);
+	return 0;
+}
+
+/*
+ * V4L2 subdev pad level and video operations
+ */
+static int s5k5baf_enum_frame_interval(struct v4l2_subdev *sd,
+			      struct v4l2_subdev_fh *fh,
+			      struct v4l2_subdev_frame_interval_enum *fie)
+{
+	if (fie->index > S5K5BAF_MAX_FR_TIME - S5K5BAF_MIN_FR_TIME ||
+	    fie->pad != 0)
+		return -EINVAL;
+
+	v4l_bound_align_image(&fie->width, S5K5BAF_WIN_WIDTH_MIN,
+			      S5K5BAF_CIS_WIDTH, 1,
+			      &fie->height, S5K5BAF_WIN_HEIGHT_MIN,
+			      S5K5BAF_CIS_HEIGHT, 1, 0);
+
+	fie->interval.numerator = S5K5BAF_MIN_FR_TIME + fie->index;
+	fie->interval.denominator = 10000;
+
+	return 0;
+}
+
+static int s5k5baf_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_fh *fh,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->pad == 0) {
+		if (code->index > 0)
+			return -EINVAL;
+		code->code = V4L2_MBUS_FMT_FIXED;
+		return 0;
+	}
+
+	if (code->index >= ARRAY_SIZE(s5k5baf_formats))
+		return -EINVAL;
+
+	code->code = s5k5baf_formats[code->index].code;
+	return 0;
+}
+
+static int s5k5baf_enum_frame_size(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_frame_size_enum *fse)
+{
+	int i;
+
+	if (fse->index > 0)
+		return -EINVAL;
+
+	if (fse->pad == 0) {
+		fse->code = V4L2_MBUS_FMT_FIXED;
+		fse->min_width = S5K5BAF_CIS_WIDTH;
+		fse->max_width = S5K5BAF_CIS_WIDTH;
+		fse->min_height = S5K5BAF_CIS_HEIGHT;
+		fse->max_height = S5K5BAF_CIS_HEIGHT;
+		return 0;
+	}
+
+	i = ARRAY_SIZE(s5k5baf_formats);
+	while (--i)
+		if (fse->code == s5k5baf_formats[i].code)
+			break;
+	fse->code = s5k5baf_formats[i].code;
+	fse->min_width = S5K5BAF_WIN_WIDTH_MIN;
+	fse->max_width = S5K5BAF_CIS_WIDTH;
+	fse->max_height = S5K5BAF_WIN_HEIGHT_MIN;
+	fse->min_height = S5K5BAF_CIS_HEIGHT;
+
+	return 0;
+}
+
+static void s5k5baf_try_cis_format(struct v4l2_mbus_framefmt *mf)
+{
+	mf->width = S5K5BAF_CIS_WIDTH;
+	mf->height = S5K5BAF_CIS_HEIGHT;
+	mf->code = V4L2_MBUS_FMT_FIXED;
+	mf->colorspace = V4L2_COLORSPACE_JPEG;
+	mf->field = V4L2_FIELD_NONE;
+}
+
+static int s5k5baf_try_isp_format(struct v4l2_mbus_framefmt *mf)
+{
+	int pixfmt;
+
+	v4l_bound_align_image(&mf->width, S5K5BAF_WIN_WIDTH_MIN,
+			      S5K5BAF_CIS_WIDTH, 1,
+			      &mf->height, S5K5BAF_WIN_HEIGHT_MIN,
+			      S5K5BAF_CIS_HEIGHT, 1, 0);
+
+	pixfmt = s5k5baf_find_pixfmt(mf);
+
+	mf->colorspace = s5k5baf_formats[pixfmt].colorspace;
+	mf->code = s5k5baf_formats[pixfmt].code;
+	mf->field = V4L2_FIELD_NONE;
+
+	return pixfmt;
+}
+
+static int s5k5baf_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
+			  struct v4l2_subdev_format *fmt)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+	const struct s5k5baf_pixfmt *pixfmt;
+	struct v4l2_mbus_framefmt *mf;
+
+	memset(fmt->reserved, 0, sizeof(fmt->reserved));

I think this should should be moved to v4l2-core/v4l2-subdev.c.
Not seem to be some drivers that don't clear this field.
I would just remove this memset from this patch.

OK

quoted

+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		mf = v4l2_subdev_get_try_format(fh, fmt->pad);
+		fmt->format = *mf;
+		return 0;
+	}
+
+	mf = &fmt->format;
+	if (fmt->pad == 0) {
+		s5k5baf_try_cis_format(mf);
+		return 0;
+	}
+	mf->field = V4L2_FIELD_NONE;
+	mutex_lock(&state->lock);
+	pixfmt = &s5k5baf_formats[state->pixfmt];
+	mf->width = state->crop_source.width;
+	mf->height = state->crop_source.height;
+	mf->code = pixfmt->code;
+	mf->colorspace = pixfmt->colorspace;
+	mutex_unlock(&state->lock);
+
+	return 0;
+}
+
+static int s5k5baf_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
+			  struct v4l2_subdev_format *fmt)
+{
+	struct v4l2_mbus_framefmt *mf = &fmt->format;
+	struct s5k5baf *state = to_s5k5baf(sd);
+	const struct s5k5baf_pixfmt *pixfmt;
+	int ret = 0;
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		*v4l2_subdev_get_try_format(fh, fmt->pad) = *mf;
+		return 0;
+	}
+
+	if (fmt->pad == 0) {
+		s5k5baf_try_cis_format(mf);
+		return 0;
+	}
+
+	mutex_lock(&state->lock);
+
+	if (state->streaming) {
+		ret = -EBUSY;
+		goto out;

It might be a matter of taste, but I think that 'goto' is not
justified  here.

OK

quoted

+	}
+
+	state->pixfmt = s5k5baf_try_isp_format(mf);
+	pixfmt = &s5k5baf_formats[state->pixfmt];
+	mf->code = pixfmt->code;
+	mf->colorspace = pixfmt->colorspace;
+	mf->width = state->crop_source.width;
+	mf->height = state->crop_source.height;
+
+out:
+	mutex_unlock(&state->lock);
+
+	return ret;
+}
+
+enum selection_rect {R_CIS, R_CROP_SINK, R_COMPOSE, R_CROP_SOURCE, R_INVALID};

Could you add spaces around { } ?

OK

quoted

+static enum selection_rect s5k5baf_get_sel_rect(u32 pad, u32 target)
+{
+	switch (target) {
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+		return pad ? R_COMPOSE : R_CIS;
+	case V4L2_SEL_TGT_CROP:
+		return pad ? R_CROP_SOURCE : R_CROP_SINK;
+	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+		return pad ? R_INVALID : R_CROP_SINK;
+	case V4L2_SEL_TGT_COMPOSE:
+		return pad ? R_INVALID : R_COMPOSE;
+	default:
+		return R_INVALID;
+	}
+}
+
+static int s5k5baf_is_bound_tgt(u32 target)

nit: s5k5baf_is_bounds_target() ?

OK

quoted

+{
+	return (target == V4L2_SEL_TGT_CROP_BOUNDS ||
+		target == V4L2_SEL_TGT_COMPOSE_BOUNDS);
+}
+

[...]

quoted

+/*
+ * V4L2 subdev controls
+ */
+
+static int s5k5baf_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
+	struct s5k5baf *state = to_s5k5baf(sd);
+	int ret;
+
+	v4l2_dbg(1, debug, sd, "ctrl: %s, value: %d\n", ctrl->name, ctrl->val);
+
+	mutex_lock(&state->lock);
+
+	if (state->power == 0)
+		goto unlock;
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUTO_WHITE_BALANCE:
+		s5k5baf_hw_set_awb(state, ctrl->val);
+		break;
+
+	case V4L2_CID_BRIGHTNESS:
+		s5k5baf_write(state, REG_USER_BRIGHTNESS, ctrl->val);
+		break;
+
+	case V4L2_CID_COLORFX:
+		s5k5baf_hw_set_colorfx(state, ctrl->val);
+		break;
+
+	case V4L2_CID_CONTRAST:
+		s5k5baf_write(state, REG_USER_CONTRAST, ctrl->val);
+		break;
+
+	case V4L2_CID_EXPOSURE_AUTO:
+		s5k5baf_hw_set_auto_exposure(state, ctrl->val);
+		break;
+
+	case V4L2_CID_HFLIP:
+		s5k5baf_hw_set_mirror(state, ctrl->val);
+		break;
+
+	case V4L2_CID_POWER_LINE_FREQUENCY:
+		s5k5baf_hw_set_anti_flicker(state, ctrl->val);
+		break;
+
+	case V4L2_CID_SATURATION:
+		s5k5baf_write(state, REG_USER_SATURATION, ctrl->val);
+		break;
+
+	case V4L2_CID_SHARPNESS:
+		s5k5baf_write(state, REG_USER_SHARPBLUR, ctrl->val);
+		break;
+
+	case V4L2_CID_WHITE_BALANCE_TEMPERATURE:
+		s5k5baf_write(state, REG_P_COLORTEMP(0), ctrl->val);
+		if (state->apply_cfg)
+			s5k5baf_hw_sync_cfg(state);
+		break;
+
+	case V4L2_CID_TEST_PATTERN:
+		s5k5baf_hw_set_test_pattern(state, ctrl->val);
+		break;
+	}
+unlock:
+	ret = s5k5baf_clear_error(state);
+	mutex_unlock(&state->lock);
+	return ret;
+}
+
+static const struct v4l2_ctrl_ops s5k5baf_ctrl_ops = {
+	.s_ctrl	= s5k5baf_s_ctrl,
+};
+
+static const char * const s5k5baf_test_pattern_menu[] = {
+	"Disabled",
+	"Blank",
+	"Bars",
+	"Gradients",
+	"Textile",
+	"Textile2",
+	"Squares"
+};
+
+static int s5k5baf_initialize_ctrls(struct s5k5baf *state)
+{
+	const struct v4l2_ctrl_ops *ops = &s5k5baf_ctrl_ops;
+	struct s5k5baf_ctrls *ctrls = &state->ctrls;
+	struct v4l2_ctrl_handler *hdl = &ctrls->handler;
+	int ret;
+
+	ret = v4l2_ctrl_handler_init(hdl, 16);

You seem to have at least 18 controls.

OK

quoted

+	if (ret) {
+		v4l2_err(&state->sd, "cannot init ctrl handler (%d)\n", ret);
+		return ret;
+	}
+
+	/* Auto white balance cluster */
+	ctrls->awb = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_AUTO_WHITE_BALANCE,
+				       0, 1, 1, 1);
+	ctrls->gain_red = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_RED_BALANCE,
+					    0, 255, 1, S5K5BAF_GAIN_RED_DEF);
+	ctrls->gain_blue = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_BLUE_BALANCE,
+					     0, 255, 1, S5K5BAF_GAIN_BLUE_DEF);
+	v4l2_ctrl_auto_cluster(3, &ctrls->awb, 0, false);
+
+	ctrls->hflip = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
+	ctrls->vflip = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
+	v4l2_ctrl_cluster(2, &ctrls->hflip);
+
+	ctrls->auto_exp = v4l2_ctrl_new_std_menu(hdl, ops,
+				V4L2_CID_EXPOSURE_AUTO,
+				V4L2_EXPOSURE_MANUAL, 0, V4L2_EXPOSURE_AUTO);
+	/* Exposure time: x 1 us */
+	ctrls->exposure = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_EXPOSURE,
+					    0, 6000000U, 1, 100000U);
+	/* Total gain: 256 <=> 1x */
+	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAIN,
+					0, 256, 1, 256);
+	v4l2_ctrl_auto_cluster(3, &ctrls->auto_exp, 0, false);
+
+	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_POWER_LINE_FREQUENCY,
+			       V4L2_CID_POWER_LINE_FREQUENCY_AUTO, 0,
+			       V4L2_CID_POWER_LINE_FREQUENCY_AUTO);
+
+	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_COLORFX,
+			       V4L2_COLORFX_SKY_BLUE, ~0x6f, V4L2_COLORFX_NONE);
+
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_WHITE_BALANCE_TEMPERATURE,
+			  0, 256, 1, 0);
+
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SATURATION, -127, 127, 1, 0);
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_BRIGHTNESS, -127, 127, 1, 0);
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_CONTRAST, -127, 127, 1, 0);
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SHARPNESS, -127, 127, 1, 0);
+
+	v4l2_ctrl_new_std_menu_items(hdl, ops, V4L2_CID_TEST_PATTERN,
+				     ARRAY_SIZE(s5k5baf_test_pattern_menu) - 1,
+				     0, 0, s5k5baf_test_pattern_menu);
+
+	if (hdl->error) {
+		v4l2_err(&state->sd, "error creating controls (%d)\n",
+			 hdl->error);
+		ret = hdl->error;
+		v4l2_ctrl_handler_free(hdl);
+		return ret;
+	}
+
+	state->sd.ctrl_handler = hdl;
+	return 0;
+}
+
+/*
+ * V4L2 subdev internal operations
+ */
+static int s5k5baf_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
+{
+	struct v4l2_mbus_framefmt *mf;
+	struct v4l2_rect *r;
+
+	mf = v4l2_subdev_get_try_format(fh, 0);
+	s5k5baf_try_cis_format(mf);
+
+	if (s5k5baf_is_cis_subdev(sd))
+		return 0;
+
+	mf = v4l2_subdev_get_try_format(fh, 1);
+	mf->colorspace = s5k5baf_formats[0].colorspace;
+	mf->code = s5k5baf_formats[0].code;
+	mf->width = s5k5baf_def_rect.width;
+	mf->height = s5k5baf_def_rect.height;
+	mf->field = V4L2_FIELD_NONE;
+
+	*v4l2_subdev_get_try_crop(fh, 0) = s5k5baf_cis_rect;
+	r = v4l2_subdev_get_try_compose(fh, 0);
+	*r = s5k5baf_def_rect;
+	*v4l2_subdev_get_try_crop(fh, 1) = *r;
+
+	return 0;
+}
+
+static void s5k5baf_check_fw_revision(struct s5k5baf *state)
+{
+	u16 api_ver = 0, fw_rev = 0, s_id = 0;
+
+	api_ver = s5k5baf_read(state, REG_FW_APIVER);
+	fw_rev = s5k5baf_read(state, REG_FW_REVISION) & 0xff;
+	s_id = s5k5baf_read(state, REG_FW_SENSOR_ID);
+	if (state->error)
+		return;
+
+	v4l2_info(&state->sd, "FW API=%#x, revision=%#x sensor_id=%#x\n",
+		  api_ver, fw_rev, s_id);
+
+	if (api_ver == S5K5BAF_FW_APIVER)
+		return;
+
+	v4l2_err(&state->sd, "FW API version not supported\n");
+	state->error = -ENODEV;
+}
+
+static int s5k5baf_registered(struct v4l2_subdev *sd)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+	int ret;
+
+	ret = v4l2_device_register_subdev(sd->v4l2_dev, &state->cis_sd);
+	if (ret) {
+		v4l2_err(sd, "failed to register subdev %s\n",
+			 state->cis_sd.name);
+		return ret;
+	}
+
+	mutex_lock(&state->lock);
+
+	s5k5baf_power_on(state);
+	s5k5baf_hw_init(state);
+	s5k5baf_check_fw_revision(state);
+	s5k5baf_power_off(state);
+	ret = s5k5baf_clear_error(state);

After the exynos4-is is converted to the asynchronous subdev probing
API this H/W revision probing could be moved to probe. For the final
version of this driver the async API support will need to be added to
this driver.

OK

quoted

+	mutex_unlock(&state->lock);
+
+	if (ret)
+		v4l2_device_unregister_subdev(&state->cis_sd);
+
+	return ret;
+}
+
+static void s5k5baf_unregistered(struct v4l2_subdev *sd)
+{
+	struct s5k5baf *state = to_s5k5baf(sd);
+	v4l2_device_unregister_subdev(&state->cis_sd);
+}
+

[...]

quoted

+static int s5k5baf_parse_device_node(struct s5k5baf *state, struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	struct device_node *node_ep;
+	struct v4l2_of_endpoint ep;
+	int ret;
+
+	if (!node) {
+		dev_err(dev, "no device-tree node provided\n");
+		return -EINVAL;
+	}
+
+	of_property_read_u32(node, "clock-frequency", &state->mclk_frequency);
+	state->hflip = of_property_read_bool(node, "samsung,hflip");
+	state->vflip = of_property_read_bool(node, "samsung,vflip");
+	ret = s5k5baf_parse_gpio(&state->gpios[STBY], node, STBY);
+	if (ret) {
+		dev_err(dev, "no standby gpio pin provided\n");
+		return -EINVAL;
+	}
+	ret = s5k5baf_parse_gpio(&state->gpios[RST], node, RST);
+	if (ret) {
+		dev_err(dev, "no reset gpio pin provided\n");
+		return -EINVAL;
+	}
+
+	node_ep = v4l2_of_get_next_endpoint(node, NULL);
+	if (!node_ep) {
+		dev_err(dev, "no endpoint defined\n");

nit:
		dev_err(dev, "no endpoint defined at node %s\n",
				node->full_name);
?

OK

quoted

+		return -EINVAL;
+	}

nit: an empty line here ?

OK

quoted

+	v4l2_of_parse_endpoint(node_ep, &ep);
+	of_node_put(node_ep);
+	state->bus_type = ep.bus_type;
+	if (state->bus_type == V4L2_MBUS_CSI2)
+		state->nlanes = ep.bus.mipi_csi2.num_data_lanes;
+	return 0;
+}
+
+static int s5k5baf_configure_subdevs(struct s5k5baf *state,
+				     struct i2c_client *c)
+{
+	struct v4l2_subdev *sd;
+	int ret;
+
+	sd = &state->cis_sd;
+	v4l2_subdev_init(sd, &s5k5baf_cis_subdev_ops);
+	sd->owner = c->driver->driver.owner;

It could be simplified to:

	sd->owner = THIS_MODULE;

OK

quoted

+	v4l2_set_subdevdata(sd, state);
+	strlcpy(sd->name, "S5K5BAF-CIS", sizeof(sd->name));

I think we need instead something like:

	snprintf(sd->name, sizeof(sd->name), "%s %d-%04x",
		"S5K5BAF-CIS", i2c_adapter_id(c->adapter), c->addr);

OK

quoted

+	sd->internal_ops = &s5k5baf_cis_subdev_internal_ops;
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	state->cis_pad.flags = MEDIA_PAD_FL_SOURCE;
+	sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_SENSOR;
+	ret = media_entity_init(&sd->entity, 1, &state->cis_pad, 0);
+	if (ret)
+		goto err;
+
+	sd = &state->sd;
+	v4l2_i2c_subdev_init(sd, c, &s5k5baf_subdev_ops);
+	strlcpy(sd->name, "S5K5BAF-ISP", sizeof(sd->name));

Ditto.

OK

quoted

+	sd->internal_ops = &s5k5baf_subdev_internal_ops;
+	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	state->pads[0].flags = MEDIA_PAD_FL_SINK;
+	state->pads[1].flags = MEDIA_PAD_FL_SOURCE;

Might be a good idea to create some enum/macros to those pad indexes.

OK

quoted

+	sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV;
+	ret = media_entity_init(&sd->entity, 2, state->pads, 0);

And for the number of pads too.

OK

quoted

+	if (ret)
+		goto err_cis;
+
+	ret = media_entity_create_link(&state->cis_sd.entity,
+				       0, &state->sd.entity, 0,
+				       MEDIA_LNK_FL_IMMUTABLE |
+				       MEDIA_LNK_FL_ENABLED);

This link needs now to be created in .registered callback, so it
is re-created after this subdev gets unregistered from the host
and the state->cis_sd.entity links get removed.

OK

quoted

+	if (!ret)
+		return 0;
+
+	media_entity_cleanup(&state->sd.entity);
+err_cis:
+	media_entity_cleanup(&state->cis_sd.entity);
+err:
+	dev_err(&c->dev, "cannot init media entity %s\n", sd->name);
+	return ret;
+}

[...]

quoted

+
+MODULE_DESCRIPTION("Samsung S5K5BAF(X) UXGA camera driver");
+MODULE_AUTHOR("Andrzej Hajda [off-list ref]");
+MODULE_LICENSE("GPL");

I think this should be "GPL v2".

OK

Regards
Andrzej

Otherwise it look pretty good! And more importantly the overall
image quality is much better than with the s5k6aa driver for
a similar sensor. :)

Thanks,
Sylwester