From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
R can select between two parents. We deal with it like this: During
initialization, check if EXTALR is populated. If so, use it for R. If
not, use R_Internal. clk_mux doesn't help here because we don't want to
switch parents depending on the clock rate. The clock rate (and source)
should stay constant for the watchdog, so I think a setup like this
during initialization makes sense.
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
Since V1: drop comment about EXTALR and RCKCR was moved to previous patch
drivers/clk/renesas/r8a7795-cpg-mssr.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/clk/renesas/r8a7795-cpg-mssr.c b/drivers/clk/renesas/r8a7795-cpg-mssr.c
index 08715ca2ebb49d..19b02645771876 100644
--- a/drivers/clk/renesas/r8a7795-cpg-mssr.c
+++ b/drivers/clk/renesas/r8a7795-cpg-mssr.c
@@ -13,6 +13,7 @@
*/
#include <linux/bug.h>
+#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/err.h>
@@ -65,6 +66,7 @@ enum r8a7795_clk_types {
CLK_TYPE_GEN3_PLL3,
CLK_TYPE_GEN3_PLL4,
CLK_TYPE_GEN3_SD,
+ CLK_TYPE_GEN3_R,
};
#define DEF_GEN3_SD(_name, _id, _parent, _offset) \
@@ -121,6 +123,8 @@ static const struct cpg_core_clk r8a7795_core_clks[] __initconst = {
DEF_DIV6_RO("osc", R8A7795_CLK_OSC, CLK_EXTAL, CPG_RCKCR, 8),
DEF_DIV6_RO("r_int", CLK_RINT, CLK_EXTAL, CPG_RCKCR, 32),
+
+ DEF_BASE("r", R8A7795_CLK_R, CLK_TYPE_GEN3_R, CLK_RINT),
};
static const struct mssr_mod_clk r8a7795_mod_clks[] __initconst = {
@@ -587,6 +591,18 @@ struct clk * __init r8a7795_cpg_clk_register(struct device *dev,
case CLK_TYPE_GEN3_SD:
return cpg_sd_clk_register(core, base, __clk_get_name(parent));
+ case CLK_TYPE_GEN3_R:
+ /* RINT is default. Only if EXTALR is populated, we switch to it */
+ value = readl(base + CPG_RCKCR) & 0x3f;
+
+ if (clk_get_rate(clks[CLK_EXTALR])) {
+ parent = clks[CLK_EXTALR];
+ value |= BIT(15);
+ }
+
+ writel(value, base + CPG_RCKCR);
+ break;
+
default:
return ERR_PTR(-EINVAL);
}
--
2.7.0
