[PATCH v3] clk-rcar-gen2: RCAN clock support

From: Sergei Shtylyov
Date: Mon Jan 05 2015 - 15:10:55 EST


Add the RCAN clock support to the R-Car generation 2 CPG driver. This clock
gets derived from the USB_EXTAL clock, dividing it by 6. The layout of the
RCANCKCR register is similar 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.shtylyov@xxxxxxxxxxxxxxxxxx>

---
Changes in version 3:
- added the USB_EXTAL clock reference to the binding document.

Changes in version 2:
- switched to using the composite clock driver with the fixed factor and gated
clock component drivers;
- removed *static* from 'parent_name' definition, switching from assignment to
initializer;
- modified the binding document;
- modified the changelog.

Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt | 10 +-
drivers/clk/shmobile/clk-rcar-gen2.c | 40 ++++++++++
2 files changed, 46 insertions(+), 4 deletions(-)

Index: renesas/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
===================================================================
--- renesas.orig/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
+++ renesas/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
@@ -13,10 +13,11 @@ Required Properties:

- reg: Base address and length of the memory resource used by the CPG

- - clocks: Reference to the parent clock
+ - clocks: References to the parent clocks: first to the EXTAL clock, second
+ to the USB_EXTAL clock
- #clock-cells: Must be 1
- clock-output-names: The names of the clocks. Supported clocks are "main",
- "pll0", "pll1", "pll3", "lb", "qspi", "sdh", "sd0", "sd1" and "z"
+ "pll0", "pll1", "pll3", "lb", "qspi", "sdh", "sd0", "sd1", "z", and "rcan"


Example
@@ -26,8 +27,9 @@ Example
compatible = "renesas,r8a7790-cpg-clocks",
"renesas,rcar-gen2-cpg-clocks";
reg = <0 0xe6150000 0 0x1000>;
- clocks = <&extal_clk>;
+ clocks = <&extal_clk &usb_extal_clk>;
#clock-cells = <1>;
clock-output-names = "main", "pll0, "pll1", "pll3",
- "lb", "qspi", "sdh", "sd0", "sd1", "z";
+ "lb", "qspi", "sdh", "sd0", "sd1", "z",
+ "rcan";
};
Index: renesas/drivers/clk/shmobile/clk-rcar-gen2.c
===================================================================
--- renesas.orig/drivers/clk/shmobile/clk-rcar-gen2.c
+++ renesas/drivers/clk/shmobile/clk-rcar-gen2.c
@@ -33,6 +33,7 @@ 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

/* -----------------------------------------------------------------------------
* Z Clock
@@ -161,6 +162,43 @@ static struct clk * __init cpg_z_clk_reg
return clk;
}

+static struct clk * __init cpg_rcan_clk_register(struct rcar_gen2_cpg *cpg,
+ struct device_node *np)
+{
+ const char *parent_name = of_clk_get_parent_name(np, 1);
+ struct clk_fixed_factor *fixed;
+ struct clk_gate *gate;
+ struct clk *clk;
+
+ fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
+ if (!fixed)
+ return ERR_PTR(-ENOMEM);
+
+ fixed->mult = 1;
+ fixed->div = 6;
+
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate) {
+ kfree(fixed);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ gate->reg = cpg->reg + CPG_RCANCKCR;
+ gate->bit_idx = 8;
+ gate->flags = CLK_GATE_SET_TO_DISABLE;
+ gate->lock = &cpg->lock;
+
+ clk = clk_register_composite(NULL, "rcan", &parent_name, 1, NULL, NULL,
+ &fixed->hw, &clk_fixed_factor_ops,
+ &gate->hw, &clk_gate_ops, 0);
+ if (IS_ERR(clk)) {
+ kfree(gate);
+ kfree(fixed);
+ }
+
+ return clk;
+}
+
/* -----------------------------------------------------------------------------
* CPG Clock Data
*/
@@ -263,6 +301,8 @@ 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);
}

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