[RFC PATCH v2 07/11] clk: imx: composite-8m: add device tree support

[Dario Binacchi]

The patch, backwards compatible, extends the driver to initialize the
clock directly from the device tree.

Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>

---

Changes in v2:
- Fix compiler warnings reported by kernel test robot.

 drivers/clk/imx/clk-composite-8m.c | 84 ++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
index cbf0d7955a00..fa5fdfff0b2d 100644
--- a/drivers/clk/imx/clk-composite-8m.c
+++ b/drivers/clk/imx/clk-composite-8m.c
@@ -7,6 +7,8 @@
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/slab.h>
 
 #include "clk.h"
@@ -25,6 +27,9 @@
 
 #define PCG_CGC_SHIFT		28
 
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
 static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
 						unsigned long parent_rate)
 {
@@ -250,3 +255,82 @@ struct clk_hw *__imx8m_clk_hw_composite(const char *name,
 	return ERR_CAST(hw);
 }
 EXPORT_SYMBOL_GPL(__imx8m_clk_hw_composite);
+
+static void __init _of_imx_composite_clk_setup(struct device_node *node,
+					       u32 type)
+{
+	void __iomem *reg;
+	struct clk_hw *hw;
+	const char *name = node->name;
+	unsigned int num_parents;
+	const char **parent_names;
+	unsigned long flags = IMX_COMPOSITE_CLK_FLAGS_DEFAULT;
+
+	reg = of_iomap(node, 0);
+	if (IS_ERR(reg)) {
+		pr_err("failed to get reg address for %pOFn\n", node);
+		return;
+	}
+
+	num_parents = of_clk_get_parent_count(node);
+	if (num_parents < 2) {
+		pr_err("%pOFn must have parents\n", node);
+		return;
+	}
+
+	parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
+	if (!parent_names)
+		return;
+
+	of_clk_parent_fill(node, parent_names, num_parents);
+	of_property_read_string(node, "clock-output-names", &name);
+
+	if (of_property_read_bool(node, "fsl,get-rate-nocache"))
+		flags |= CLK_GET_RATE_NOCACHE;
+
+	if (of_property_read_bool(node, "fsl,is-critical"))
+		flags |= CLK_IS_CRITICAL;
+
+	hw = __imx8m_clk_hw_composite(name, parent_names, num_parents, reg,
+				      type, flags);
+	if (!IS_ERR(hw))
+		of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
+
+	kfree(parent_names);
+}
+
+/**
+ * of_imx_composite_clk_setup() - Setup function for imx composite  clock
+ * @node:	device node for the clock
+ */
+static void __init of_imx_composite_clk_setup(struct device_node *node)
+{
+	_of_imx_composite_clk_setup(node, IMX_COMPOSITE_CORE);
+}
+CLK_OF_DECLARE(fsl_composite_8m_clk, "fsl,imx8m-composite-clock",
+	       of_imx_composite_clk_setup);
+
+/**
+ * of_imx_composite_bus_clk_setup() - Setup function for imx composite  clock
+ * @node:	device node for the clock
+ */
+static void __init of_imx_composite_bus_clk_setup(struct device_node *node)
+{
+	_of_imx_composite_clk_setup(node, IMX_COMPOSITE_BUS);
+}
+CLK_OF_DECLARE(fsl_composite_bus_8m_clk, "fsl,imx8m-composite-bus-clock",
+	       of_imx_composite_bus_clk_setup);
+
+/**
+ * of_imx_composite_fw_managed_clk_setup() - Setup function for imx
+ *		composite fw managed clock
+ * @node:	device node for the clock
+ */
+static void __init
+of_imx_composite_fw_managed_clk_setup(struct device_node *node)
+{
+	_of_imx_composite_clk_setup(node, IMX_COMPOSITE_FW_MANAGED);
+}
+CLK_OF_DECLARE(fsl_composite_fw_managed_8m_clk,
+	       "fsl,imx8m-composite-fw-managed-clock",
+	       of_imx_composite_fw_managed_clk_setup);
-- 
2.32.0