clk: ux500: Add a 2-cell Device Tree parser for obtaining PRCC clocks

PRCC (peripheral and kernel) clocks are specified using a property tuple
<&phandle base bit>, where 'base' is the peripheral (1, 2, 3, 5 or 6),
and bit is read-in value into that peripheral stipulated by the hardware
specification.

Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/clk/ux500/u8500_of_clk.c b/drivers/clk/ux500/u8500_of_clk.c
index bfbe3cae72d7..b9b3317bdc2f 100644
--- a/drivers/clk/ux500/u8500_of_clk.c
+++ b/drivers/clk/ux500/u8500_of_clk.c
@@ -15,6 +15,28 @@
 #include <linux/platform_data/clk-ux500.h>
 #include "clk.h"
 
+#define PRCC_SHOW(clk, base, bit) \
+        clk[(base * PRCC_PERIPHS_PER_CLUSTER) + bit]
+
+struct clk *ux500_twocell_get(struct of_phandle_args *clkspec, void *data)
+{
+        struct clk **clk_data = data;
+        unsigned int base, bit;
+
+        if (clkspec->args_count != 2)
+                return  ERR_PTR(-EINVAL);
+
+        base = clkspec->args[0];
+        bit = clkspec->args[1];
+
+        if (base != 1 && base != 2 && base != 3 && base != 5 && base != 6) {
+                pr_err("%s: invalid PRCC base %d\n", __func__, base);
+                return ERR_PTR(-EINVAL);
+        }
+
+        return PRCC_SHOW(clk_data, base, bit);
+}
+
 static const struct of_device_id u8500_clk_of_match[] = {
         { .compatible = "stericsson,u8500-clks", },
         { },