[PATCH v2 17/30] ccs: Read ireal numbers correctly

[Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>]

Some limit values are available in q16.q16 format, referred to as 32-bit
unsigned ireal in CCS. Read these correctly.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
 drivers/media/i2c/ccs/ccs-core.c       | 10 ++--------
 drivers/media/i2c/ccs/ccs-reg-access.c | 23 +++++++++++++++++++++--
 drivers/media/i2c/ccs/ccs.h            |  9 +++++++++
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
index 57efc34fc67d..074b246538d2 100644
--- a/drivers/media/i2c/ccs/ccs-core.c
+++ b/drivers/media/i2c/ccs/ccs-core.c
@@ -126,8 +126,8 @@ void ccs_replace_limit(struct ccs_sensor *sensor,
 	ccs_assign_limit(ptr, ccs_reg_width(linfo->reg), val);
 }
 
-static u32 ccs_get_limit(struct ccs_sensor *sensor,
-			 unsigned int limit, unsigned int offset)
+u32 ccs_get_limit(struct ccs_sensor *sensor, unsigned int limit,
+		  unsigned int offset)
 {
 	void *ptr;
 	u32 val;
@@ -155,12 +155,6 @@ static u32 ccs_get_limit(struct ccs_sensor *sensor,
 	return ccs_reg_conv(sensor, ccs_limits[limit].reg, val);
 }
 
-#define CCS_LIM(sensor, limit) \
-	ccs_get_limit(sensor, CCS_L_##limit, 0)
-
-#define CCS_LIM_AT(sensor, limit, offset)	\
-	ccs_get_limit(sensor, CCS_L_##limit, CCS_L_##limit##_OFFSET(offset))
-
 static int ccs_read_all_limits(struct ccs_sensor *sensor)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
diff --git a/drivers/media/i2c/ccs/ccs-reg-access.c b/drivers/media/i2c/ccs/ccs-reg-access.c
index fe6112cba6be..91ccbca11577 100644
--- a/drivers/media/i2c/ccs/ccs-reg-access.c
+++ b/drivers/media/i2c/ccs/ccs-reg-access.c
@@ -15,6 +15,7 @@
 #include <linux/i2c.h>
 
 #include "ccs.h"
+#include "ccs-limits.h"
 
 static uint32_t float_to_u32_mul_1000000(struct i2c_client *client,
 					 uint32_t phloat)
@@ -143,12 +144,30 @@ unsigned int ccs_reg_width(u32 reg)
 	return sizeof(uint8_t);
 }
 
+static u32 ireal32_to_u32_mul_1000000(struct i2c_client *client, u32 val)
+{
+	if (val >> 10 > U32_MAX / 15625) {
+		dev_warn(&client->dev, "value %u overflows!\n", val);
+		return U32_MAX;
+	}
+
+	return ((val >> 10) * 15625) +
+		(val & GENMASK(9, 0)) * 15625 / 1024;
+}
+
 u32 ccs_reg_conv(struct ccs_sensor *sensor, u32 reg, u32 val)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
 
-	if (reg & CCS_FL_FLOAT_IREAL)
-		val = float_to_u32_mul_1000000(client, val);
+	if (reg & CCS_FL_FLOAT_IREAL) {
+		if (CCS_LIM(sensor, CLOCK_CAPA_TYPE_CAPABILITY) &
+		    CCS_CLOCK_CAPA_TYPE_CAPABILITY_IREAL)
+			val = ireal32_to_u32_mul_1000000(client, val);
+		else
+			val = float_to_u32_mul_1000000(client, val);
+	} else if (reg & CCS_FL_IREAL) {
+		val = ireal32_to_u32_mul_1000000(client, val);
+	}
 
 	return val;
 }
diff --git a/drivers/media/i2c/ccs/ccs.h b/drivers/media/i2c/ccs/ccs.h
index cbcd93b519da..f60d1801c469 100644
--- a/drivers/media/i2c/ccs/ccs.h
+++ b/drivers/media/i2c/ccs/ccs.h
@@ -17,6 +17,7 @@
 #include <media/v4l2-subdev.h>
 
 #include "ccs-data.h"
+#include "ccs-limits.h"
 #include "ccs-quirk.h"
 #include "ccs-regs.h"
 #include "ccs-reg-access.h"
@@ -50,6 +51,12 @@
 #define CCS_DFL_I2C_ADDR	(0x20 >> 1) /* Default I2C Address */
 #define CCS_ALT_I2C_ADDR	(0x6e >> 1) /* Alternate I2C Address */
 
+#define CCS_LIM(sensor, limit) \
+	ccs_get_limit(sensor, CCS_L_##limit, 0)
+
+#define CCS_LIM_AT(sensor, limit, offset)	\
+	ccs_get_limit(sensor, CCS_L_##limit, CCS_L_##limit##_OFFSET(offset))
+
 /*
  * Sometimes due to board layout considerations the camera module can be
  * mounted rotated. The typical rotation used is 180 degrees which can be
@@ -277,5 +284,7 @@ struct ccs_sensor {
 
 void ccs_replace_limit(struct ccs_sensor *sensor,
 		       unsigned int limit, unsigned int offset, u32 val);
+u32 ccs_get_limit(struct ccs_sensor *sensor, unsigned int limit,
+		  unsigned int offset);
 
 #endif /* __CCS_H__ */
-- 
2.27.0