clk: at91: pmc: add helpers for clock drivers

Add helper for clock drivers. These will be used by following
commits in the process of switching AT91 clock drivers to CCF.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>

drivers/clk/at91/pmc.c

@@ -120,3 +120,94 @@ int at91_clk_probe(struct udevice *dev)
 
 	return 0;
 }
+
+/**
+ * pmc_read() - read content at address base + off into val
+ *
+ * @base: base address
+ * @off: offset to read from
+ * @val: where the content of base + off is stored
+ *
+ * @return: void
+ */
+void pmc_read(void __iomem *base, unsigned int off, unsigned int *val)
+{
+	*val = readl(base + off);
+}
+
+/**
+ * pmc_write() - write content of val at address base + off
+ *
+ * @base: base address
+ * @off: offset to write to
+ * @val: content to be written at base + off
+ *
+ * @return: void
+ */
+void pmc_write(void __iomem *base, unsigned int off, unsigned int val)
+{
+	writel(val, base + off);
+}
+
+/**
+ * pmc_update_bits() - update a set of bits at address base + off
+ *
+ * @base: base address
+ * @off: offset to be updated
+ * @mask: mask of bits to be updated
+ * @bits: the new value to be updated
+ *
+ * @return: void
+ */
+void pmc_update_bits(void __iomem *base, unsigned int off,
+		     unsigned int mask, unsigned int bits)
+{
+	unsigned int tmp;
+
+	tmp = readl(base + off);
+	tmp &= ~mask;
+	writel(tmp | (bits & mask), base + off);
+}
+
+/**
+ * at91_clk_mux_val_to_index() - get parent index in mux table
+ *
+ * @table: clock mux table
+ * @num_parents: clock number of parents
+ * @val: clock id who's mux index should be retrieved
+ *
+ * @return: clock index in mux table or a negative error number in case of
+ *		failure
+ */
+int at91_clk_mux_val_to_index(const u32 *table, u32 num_parents, u32 val)
+{
+	int i;
+
+	if (!table || !num_parents)
+		return -EINVAL;
+
+	for (i = 0; i < num_parents; i++) {
+		if (table[i] == val)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * at91_clk_mux_index_to_val() - get parent ID corresponding to an entry in
+ *	clock's mux table
+ *
+ * @table: clock's mux table
+ * @num_parents: clock's number of parents
+ * @index: index in mux table which clock's ID should be retrieved
+ *
+ * @return: clock ID or a negative error number in case of failure
+ */
+int at91_clk_mux_index_to_val(const u32 *table, u32 num_parents, u32 index)
+{
+	if (!table || !num_parents || index < 0 || index > num_parents)
+		return -EINVAL;
+
+	return table[index];
+}

drivers/clk/at91/pmc.h

@@ -8,6 +8,12 @@
 #define __AT91_PMC_H__
 
 #include <regmap.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+
+/* Keep a range of 256 available clocks for every clock type. */
+#define AT91_TO_CLK_ID(_t, _i)		(((_t) << 8) | ((_i) & 0xff))
+#define AT91_CLK_ID_TO_DID(_i)		((_i) & 0xff)
 
 struct pmc_platdata {
 	struct at91_pmc *reg_base;
@@ -20,4 +26,11 @@ int at91_clk_sub_device_bind(struct udevice *dev, const char *drv_name);
 int at91_clk_of_xlate(struct clk *clk, struct ofnode_phandle_args *args);
 int at91_clk_probe(struct udevice *dev);
 
+int at91_clk_mux_val_to_index(const u32 *table, u32 num_parents, u32 val);
+int at91_clk_mux_index_to_val(const u32 *table, u32 num_parents, u32 index);
+
+void pmc_read(void __iomem *base, unsigned int off, unsigned int *val);
+void pmc_write(void __iomem *base, unsigned int off, unsigned int val);
+void pmc_update_bits(void __iomem *base, unsigned int off, unsigned int mask,
+			unsigned int bits);
 #endif