[media] media: st-rc: Add reset support

Some of the SOCs hold the IRB IP in softreset state by default.
For this IP to work driver needs to bring it out of softreset.
This patch adds support to reset the IP via reset framework.

Without this patch the driver can not work with SoCs which holds the IP
in softreset.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/rc/st_rc.c

@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <media/rc-core.h>
 #include <linux/pinctrl/consumer.h>
 
@@ -28,6 +29,7 @@ struct st_rc_device {
 	int				sample_mult;
 	int				sample_div;
 	bool				rxuhfmode;
+	struct	reset_control		*rstc;
 };
 
 /* Registers */
@@ -161,6 +163,10 @@ static void st_rc_hardware_init(struct st_rc_device *dev)
 	unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
 	unsigned int rx_sampling_freq_div;
 
+	/* Enable the IP */
+	if (dev->rstc)
+		reset_control_deassert(dev->rstc);
+
 	clk_prepare_enable(dev->sys_clock);
 	baseclock = clk_get_rate(dev->sys_clock);
 
@@ -271,6 +277,11 @@ static int st_rc_probe(struct platform_device *pdev)
 	else
 		rc_dev->rx_base = rc_dev->base;
 
+
+	rc_dev->rstc = reset_control_get(dev, NULL);
+	if (IS_ERR(rc_dev->rstc))
+		rc_dev->rstc = NULL;
+
 	rc_dev->dev = dev;
 	platform_set_drvdata(pdev, rc_dev);
 	st_rc_hardware_init(rc_dev);
@@ -338,6 +349,8 @@ static int st_rc_suspend(struct device *dev)
 		writel(0x00, rc_dev->rx_base + IRB_RX_EN);
 		writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
 		clk_disable_unprepare(rc_dev->sys_clock);
+		if (rc_dev->rstc)
+			reset_control_assert(rc_dev->rstc);
 	}
 
 	return 0;