From 1b398012cee8d6c9fff15d74e462a5ace6f9ef7c Mon Sep 17 00:00:00 2001
From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: Thu, 3 Sep 2020 21:52:29 +0200
Subject: [PATCH] media: ccs: Use static data read-only registers

Access read-only registers from CCS static data.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/i2c/ccs/ccs-reg-access.c | 64 +++++++++++++++++++++++++++++++---
 1 file changed, 60 insertions(+), 4 deletions(-)

diff --git a/drivers/media/i2c/ccs/ccs-reg-access.c b/drivers/media/i2c/ccs/ccs-reg-access.c
index 918bc98c226f..3de863e3bf26 100644
--- a/drivers/media/i2c/ccs/ccs-reg-access.c
+++ b/drivers/media/i2c/ccs/ccs-reg-access.c
@@ -198,11 +198,67 @@ static int __ccs_read_addr(struct ccs_sensor *sensor, u32 reg, u32 *val,
 	return 0;
 }
 
+static int __ccs_read_data(struct ccs_reg *regs, size_t num_regs,
+			   u32 reg, u32 *val)
+{
+	unsigned int width = ccs_reg_width(reg);
+	size_t i;
+
+	for (i = 0; i < num_regs; i++, regs++) {
+		uint8_t *data;
+
+		if (regs->addr + regs->len < CCS_REG_ADDR(reg) + width)
+			continue;
+
+		if (regs->addr > CCS_REG_ADDR(reg))
+			break;
+
+		data = &regs->value[CCS_REG_ADDR(reg) - regs->addr];
+
+		switch (width) {
+		case sizeof(uint8_t):
+			*val = *data;
+			break;
+		case sizeof(uint16_t):
+			*val = get_unaligned_be16(data);
+			break;
+		case sizeof(uint32_t):
+			*val = get_unaligned_be32(data);
+			break;
+		default:
+			WARN_ON(1);
+			return -EINVAL;
+		}
+
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+static int ccs_read_data(struct ccs_sensor *sensor, u32 reg, u32 *val)
+{
+	if (!__ccs_read_data(sensor->sdata.sensor_read_only_regs,
+			     sensor->sdata.num_sensor_read_only_regs,
+			     reg, val))
+		return 0;
+
+	return __ccs_read_data(sensor->mdata.module_read_only_regs,
+			       sensor->mdata.num_module_read_only_regs,
+			       reg, val);
+}
+
 static int ccs_read_addr_raw(struct ccs_sensor *sensor, u32 reg, u32 *val,
-			     bool force8, bool quirk, bool conv)
+			     bool force8, bool quirk, bool conv, bool data)
 {
 	int rval;
 
+	if (data) {
+		rval = ccs_read_data(sensor, reg, val);
+		if (!rval)
+			return 0;
+	}
+
 	if (quirk) {
 		*val = 0;
 		rval = ccs_call_quirk(sensor, reg_access, false, &reg, val);
@@ -223,17 +279,17 @@ static int ccs_read_addr_raw(struct ccs_sensor *sensor, u32 reg, u32 *val,
 
 int ccs_read_addr(struct ccs_sensor *sensor, u32 reg, u32 *val)
 {
-	return ccs_read_addr_raw(sensor, reg, val, false, true, true);
+	return ccs_read_addr_raw(sensor, reg, val, false, true, true, true);
 }
 
 int ccs_read_addr_8only(struct ccs_sensor *sensor, u32 reg, u32 *val)
 {
-	return ccs_read_addr_raw(sensor, reg, val, true, true, true);
+	return ccs_read_addr_raw(sensor, reg, val, true, true, true, true);
 }
 
 int ccs_read_addr_noconv(struct ccs_sensor *sensor, u32 reg, u32 *val)
 {
-	return ccs_read_addr_raw(sensor, reg, val, false, true, false);
+	return ccs_read_addr_raw(sensor, reg, val, false, true, false, true);
 }
 
 static int ccs_write_retry(struct i2c_client *client, struct i2c_msg *msg)
-- 
2.11.0