Add RCAN clock support to the R-Car generation 2 CPG driver. This clock gets
derived from the USB_EXTAL clock by dividing it by 6. The layout of RCANCKCR
register is close to those of the clocks supported by the 'clk-div6' driver
but has no divider field, and so can't be supported by that driver...
Signed-off-by: Sergei Shtylyov <sergei.shtyl...@cogentembedded.com>
---
The patch is against the 'clk-next' branch of Mike Turquette's 'linux.git' repo.
drivers/clk/shmobile/clk-rcar-gen2.c | 99 +++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
Index: linux/drivers/clk/shmobile/clk-rcar-gen2.c
===================================================================
--- linux.orig/drivers/clk/shmobile/clk-rcar-gen2.c
+++ linux/drivers/clk/shmobile/clk-rcar-gen2.c
@@ -33,6 +33,8 @@ struct rcar_gen2_cpg {
#define CPG_FRQCRC 0x000000e0
#define CPG_FRQCRC_ZFC_MASK (0x1f << 8)
#define CPG_FRQCRC_ZFC_SHIFT 8
+#define CPG_RCANCKCR 0x00000270
+#define CPG_RCANCKCR_CKSTP BIT(8)
/*
-----------------------------------------------------------------------------
* Z Clock
@@ -162,6 +164,101 @@ static struct clk * __init cpg_z_clk_reg
}
/*
-----------------------------------------------------------------------------
+ * RCAN Clock
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable clears RCANCKCR.CKSTP bit
+ * rate - rate is adjustable. clk->rate = parent->rate / 6
+ * parent - fixed parent. No clk_set_parent support
+ */
+struct cpg_rcan_clk {
+ struct clk_hw hw;
+ void __iomem *reg;
+};
+
+#define to_rcan_clk(_hw) container_of(_hw, struct cpg_rcan_clk, hw)
+
+static unsigned long cpg_rcan_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return parent_rate / 6;
+}
+
+static long cpg_rcan_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ return *parent_rate / 6;
+}
+
+static int cpg_rcan_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ return 0;
+}
+
+static int cpg_rcan_clk_enable(struct clk_hw *hw)
+{
+ struct cpg_rcan_clk *clock = to_rcan_clk(hw);
+
+ clk_writel(clk_readl(clock->reg) & ~CPG_RCANCKCR_CKSTP, clock->reg);
+
+ return 0;
+}
+
+static void cpg_rcan_clk_disable(struct clk_hw *hw)
+{
+ struct cpg_rcan_clk *clock = to_rcan_clk(hw);
+
+ clk_writel(clk_readl(clock->reg) | CPG_RCANCKCR_CKSTP, clock->reg);
+}
+
+static int cpg_rcan_clk_is_enabled(struct clk_hw *hw)
+{
+ struct cpg_rcan_clk *clock = to_rcan_clk(hw);
+
+ return !(clk_readl(clock->reg) & CPG_RCANCKCR_CKSTP);
+}
+
+static const struct clk_ops cpg_rcan_clk_ops = {
+ .enable = cpg_rcan_clk_enable,
+ .disable = cpg_rcan_clk_disable,
+ .is_enabled = cpg_rcan_clk_is_enabled,
+ .recalc_rate = cpg_rcan_clk_recalc_rate,
+ .round_rate = cpg_rcan_clk_round_rate,
+ .set_rate = cpg_rcan_clk_set_rate,
+};
+
+static struct clk * __init cpg_rcan_clk_register(struct rcar_gen2_cpg *cpg,
+ struct device_node *np)
+{
+ static const char *parent_name;
+ struct clk_init_data init;
+ struct cpg_rcan_clk *rcanclk;
+ struct clk *clk;
+
+ rcanclk = kzalloc(sizeof(*rcanclk), GFP_KERNEL);
+ if (!rcanclk)
+ return ERR_PTR(-ENOMEM);
+
+ parent_name = of_clk_get_parent_name(np, 1);
+
+ init.name = "rcan";
+ init.ops = &cpg_rcan_clk_ops;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ rcanclk->reg = cpg->reg + CPG_RCANCKCR;
+ rcanclk->hw.init = &init;
+
+ clk = clk_register(NULL, &rcanclk->hw);
+ if (IS_ERR(clk))
+ kfree(rcanclk);
+
+ return clk;
+}
+
+/*
-----------------------------------------------------------------------------
* CPG Clock Data
*/
@@ -262,6 +359,8 @@ rcar_gen2_cpg_register_clock(struct devi
shift = 0;
} else if (!strcmp(name, "z")) {
return cpg_z_clk_register(cpg);
+ } else if (!strcmp(name, "rcan")) {
+ return cpg_rcan_clk_register(cpg, np);
} else {
return ERR_PTR(-EINVAL);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
