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authorHaojian Zhuang <haojian.zhuang@linaro.org>2013-06-08 22:47:17 +0800
committerMike Turquette <mturquette@linaro.org>2013-06-15 20:23:36 -0700
commitba492e900704ba00d43c7af9d94b00da4df52587 (patch)
tree497484f3a3a8c796ccab042ba7be5a81e15d871b
parentf3aab5d61400b794ec759b9345e93e7ba57eb369 (diff)
clk: mux: add CLK_MUX_HIWORD_MASK
In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the paradigm of reading-changing-writing the register contents. Instead they use a hiword mask to indicate the changed bits. When b01 should be set as switching mux, it also needs to indicate the change by setting hiword mask (b11 << 16). The patch adds mux flag for this usage. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
-rw-r--r--drivers/clk/clk-mux.c17
-rw-r--r--include/linux/clk-provider.h5
2 files changed, 20 insertions, 2 deletions
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 25b1734560d0..614444ca40cd 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -86,8 +86,12 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
if (mux->lock)
spin_lock_irqsave(mux->lock, flags);
- val = readl(mux->reg);
- val &= ~(mux->mask << mux->shift);
+ if (mux->flags & CLK_MUX_HIWORD_MASK) {
+ val = mux->mask << (mux->shift + 16);
+ } else {
+ val = readl(mux->reg);
+ val &= ~(mux->mask << mux->shift);
+ }
val |= index << mux->shift;
writel(val, mux->reg);
@@ -111,6 +115,15 @@ struct clk *clk_register_mux_table(struct device *dev, const char *name,
struct clk_mux *mux;
struct clk *clk;
struct clk_init_data init;
+ u8 width = 0;
+
+ if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
+ width = fls(mask) - ffs(mask) + 1;
+ if (width + shift > 16) {
+ pr_err("mux value exceeds LOWORD field\n");
+ return ERR_PTR(-EINVAL);
+ }
+ }
/* allocate the mux */
mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 265f384f1e01..37ad97961e5a 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -299,6 +299,10 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name,
* Flags:
* CLK_MUX_INDEX_ONE - register index starts at 1, not 0
* CLK_MUX_INDEX_BIT - register index is a single bit (power of two)
+ * CLK_MUX_HIWORD_MASK - The mux settings are only in lower 16-bit of this
+ * register, and mask of mux bits are in higher 16-bit of this register.
+ * While setting the mux bits, higher 16-bit should also be updated to
+ * indicate changing mux bits.
*/
struct clk_mux {
struct clk_hw hw;
@@ -312,6 +316,7 @@ struct clk_mux {
#define CLK_MUX_INDEX_ONE BIT(0)
#define CLK_MUX_INDEX_BIT BIT(1)
+#define CLK_MUX_HIWORD_MASK BIT(2)
extern const struct clk_ops clk_mux_ops;