[media] exynos4-is: Remove dependency on SYSCON for non-dt platforms

Currently the whole driver depends on MFD_SYSCON, which in turn
depends on OF. To allow to use the driver on non-dt platforms
(S5PV210) the SYSREG support is made conditional (it is needed
only for dt enabled platforms) and MFD_SYSCON is selected if
OF is enabled, instead of depending on OF.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/exynos4-is/Kconfig

@@ -2,7 +2,6 @@
 config VIDEO_SAMSUNG_EXYNOS4_IS
 	bool "Samsung S5P/EXYNOS4 SoC series Camera Subsystem driver"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && PLAT_S5P && PM_RUNTIME
-	depends on MFD_SYSCON
 	help
 	  Say Y here to enable camera host interface devices for
 	  Samsung S5P and EXYNOS SoC series.
@@ -14,6 +13,7 @@ config VIDEO_S5P_FIMC
 	depends on I2C
 	select VIDEOBUF2_DMA_CONTIG
 	select V4L2_MEM2MEM_DEV
+	select MFD_SYSCON if OF
 	help
 	  This is a V4L2 driver for Samsung S5P and EXYNOS4 SoC camera host
 	  interface and video postprocessor (FIMC) devices.

drivers/media/platform/exynos4-is/fimc-core.c

@@ -966,8 +966,7 @@ static int fimc_probe(struct platform_device *pdev)
 	spin_lock_init(&fimc->slock);
 	mutex_init(&fimc->lock);
 
-	fimc->sysreg = syscon_regmap_lookup_by_phandle(dev->of_node,
-						"samsung,sysreg");
+	fimc->sysreg = fimc_get_sysreg_regmap(dev->of_node);
 	if (IS_ERR(fimc->sysreg))
 		return PTR_ERR(fimc->sysreg);
 

drivers/media/platform/exynos4-is/fimc-core.h

@@ -15,6 +15,7 @@
 #include <linux/regmap.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
 #include <linux/types.h>
 #include <linux/videodev2.h>
 #include <linux/io.h>
@@ -645,6 +646,15 @@ void fimc_unregister_m2m_device(struct fimc_dev *fimc);
 int fimc_register_driver(void);
 void fimc_unregister_driver(void);
 
+#ifdef CONFIG_MFD_SYSCON
+static inline struct regmap * fimc_get_sysreg_regmap(struct device_node *node)
+{
+	return syscon_regmap_lookup_by_phandle(node, "samsung,sysreg");
+}
+#else
+#define fimc_get_sysreg_regmap(node) (NULL)
+#endif
+
 /* -----------------------------------------------------*/
 /* fimc-m2m.c */
 void fimc_m2m_job_finish(struct fimc_ctx *ctx, int vb_state);

drivers/media/platform/exynos4-is/fimc-reg.c

@@ -805,6 +805,9 @@ int fimc_hw_camblk_cfg_writeback(struct fimc_dev *fimc)
 	unsigned int mask, val, camblk_cfg;
 	int ret;
 
+	if (map == NULL)
+		return 0;
+
 	ret = regmap_read(map, SYSREG_CAMBLK, &camblk_cfg);
 	if (ret < 0 || ((camblk_cfg & 0x00700000) >> 20 != 0x3))
 		return ret;