clk: renesas: Add and enable CPG reset driver

Add trivial reset driver extension to the CPG clock driver. The change
turns current CPG UCLASS_CLK driver instance into an UCLASS_NOP proxy
driver, which in turn binds both generic rcar3_clk UCLASS_CLK clock
driver as well as generic rcar_rst UCLASS_RESET reset driver to the
CPG DT node. This way, any other drivers which use the 'reset' DT
property can now obtain valid reset handle backed by a reset driver.

The clock tables have been updated to represent the CPG driver and only
implement the generic CPG proxy driver bind call, which binds the clock
and reset drivers.

The DM_RESET is now enabled for all R-Car Gen3 platforms.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/drivers/clk/renesas/clk-rcar-gen3.c b/drivers/clk/renesas/clk-rcar-gen3.c
index 94715bb..3611bdb 100644
--- a/drivers/clk/renesas/clk-rcar-gen3.c
+++ b/drivers/clk/renesas/clk-rcar-gen3.c
@@ -13,12 +13,15 @@
 #include <common.h>
 #include <clk-uclass.h>
 #include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
 #include <errno.h>
 #include <log.h>
 #include <wait_bit.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
 #include <linux/bitops.h>
+#include <reset-uclass.h>
 
 #include <dt-bindings/clock/renesas-cpg-mssr.h>
 
@@ -389,7 +392,7 @@
 	.of_xlate	= gen3_clk_of_xlate,
 };
 
-int gen3_clk_probe(struct udevice *dev)
+static int gen3_clk_probe(struct udevice *dev)
 {
 	struct gen3_clk_priv *priv = dev_get_priv(dev);
 	struct cpg_mssr_info *info =
@@ -447,9 +450,84 @@
 	return 0;
 }
 
-int gen3_clk_remove(struct udevice *dev)
+static int gen3_clk_remove(struct udevice *dev)
 {
 	struct gen3_clk_priv *priv = dev_get_priv(dev);
 
 	return renesas_clk_remove(priv->base, priv->info);
 }
+
+U_BOOT_DRIVER(clk_gen3) = {
+	.name		= "clk_gen3",
+	.id		= UCLASS_CLK,
+	.priv_auto	= sizeof(struct gen3_clk_priv),
+	.ops		= &gen3_clk_ops,
+	.probe		= gen3_clk_probe,
+	.remove		= gen3_clk_remove,
+};
+
+static int gen3_reset_assert(struct reset_ctl *reset_ctl)
+{
+	struct udevice *cdev = (struct udevice *)dev_get_driver_data(reset_ctl->dev);
+	struct gen3_clk_priv *priv = dev_get_priv(cdev);
+	unsigned int reg = reset_ctl->id / 32;
+	unsigned int bit = reset_ctl->id % 32;
+	u32 bitmask = BIT(bit);
+
+	writel(bitmask, priv->base + priv->info->reset_regs[reg]);
+
+	return 0;
+}
+
+static int gen3_reset_deassert(struct reset_ctl *reset_ctl)
+{
+	struct udevice *cdev = (struct udevice *)dev_get_driver_data(reset_ctl->dev);
+	struct gen3_clk_priv *priv = dev_get_priv(cdev);
+	unsigned int reg = reset_ctl->id / 32;
+	unsigned int bit = reset_ctl->id % 32;
+	u32 bitmask = BIT(bit);
+
+	writel(bitmask, priv->base + priv->info->reset_clear_regs[reg]);
+
+	return 0;
+}
+
+static const struct reset_ops rst_gen3_ops = {
+	.rst_assert = gen3_reset_assert,
+	.rst_deassert = gen3_reset_deassert,
+};
+
+U_BOOT_DRIVER(rst_gen3) = {
+	.name = "rst_gen3",
+	.id = UCLASS_RESET,
+	.ops = &rst_gen3_ops,
+};
+
+int gen3_cpg_bind(struct udevice *parent)
+{
+	struct cpg_mssr_info *info =
+		(struct cpg_mssr_info *)dev_get_driver_data(parent);
+	struct udevice *cdev, *rdev;
+	struct driver *drv;
+	int ret;
+
+	drv = lists_driver_lookup_name("clk_gen3");
+	if (!drv)
+		return -ENOENT;
+
+	ret = device_bind_with_driver_data(parent, drv, "clk_gen3", (ulong)info,
+					   dev_ofnode(parent), &cdev);
+	if (ret)
+		return ret;
+
+	drv = lists_driver_lookup_name("rst_gen3");
+	if (!drv)
+		return -ENOENT;
+
+	ret = device_bind_with_driver_data(parent, drv, "rst_gen3", (ulong)cdev,
+					   dev_ofnode(parent), &rdev);
+	if (ret)
+		device_unbind(cdev);
+
+	return ret;
+}