[PATCH v3 3/4] clk: renesas: rcar-gen3-cpg: add RPC clocks

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

The RPCSRC internal clock is controlled by the RPCCKCR.DIV[4:3] on all
the R-Car gen3 SoCs except V3M (R8A77970) but the encoding of this field
is different between SoCs; it makes sense to support the most common case
of this encoding in the R-Car gen3 CPG driver...

After adding the RPCSRC clock, we can add the RPC[D2] clocks derived from
it and controlled by the RPCCKCR register on all the R-Car gen3 SoCs except
V3M (R8A77970); the composite clock driver seems handy for this task, using
the spinlock added in the previous patch...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
Changes in version 3:
- added 'struct rpcd2_clock' embracing both 'struct clk_fixed_factor' and
  'struct clk_gate' to reduce the # of kzalloc() calls;
- added a comment about the single notifier to 'struct rpc_clock';
- refreshed the patch.

Changes in version 2:
- merged in the RPCD2 clock support from the next patch;
- moved in the RPCSRC clock support from the R8A77980 CPG/MSSR driver patch;
- switched the RPC and RPCSD2 clock support to the composite clock driver;
- changed the 1st parameter of cpg_rpc[d2]_clk_register();
- rewrote the patch description, renamed the patch.

 drivers/clk/renesas/rcar-gen3-cpg.c |   99 ++++++++++++++++++++++++++++++++++++
 drivers/clk/renesas/rcar-gen3-cpg.h |    4 +
 2 files changed, 103 insertions(+)

Index: renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.c
===================================================================
--- renesas-drivers.orig/drivers/clk/renesas/rcar-gen3-cpg.c
+++ renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.c
@@ -422,6 +422,90 @@ free_clock:
 	return clk;
 }
 
+struct rpc_clock {
+	struct clk_divider div;
+	struct clk_gate gate;
+	/*
+	 * One notifier covers both RPC and RPCD2 clocks as they are both
+	 * controlled by the same RPCCKCR register...
+	 */
+	struct cpg_simple_notifier csn;
+};
+
+static const struct clk_div_table cpg_rpcsrc_div_table[] = {
+	{ 2, 5 }, { 3, 6 }, { 0, 0 },
+};
+
+static const struct clk_div_table cpg_rpc_div_table[] = {
+	{ 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 }, { 0, 0 },
+};
+
+static struct clk * __init cpg_rpc_clk_register(const char *name,
+	void __iomem *base, const char *parent_name,
+	struct raw_notifier_head *notifiers)
+{
+	struct rpc_clock *rpc;
+	struct clk *clk;
+
+	rpc = kzalloc(sizeof(*rpc), GFP_KERNEL);
+	if (!rpc)
+		return ERR_PTR(-ENOMEM);
+
+	rpc->div.reg = base + CPG_RPCCKCR;
+	rpc->div.width = 3;
+	rpc->div.table = cpg_rpc_div_table;
+	rpc->div.lock = &cpg_lock;
+
+	rpc->gate.reg = base + CPG_RPCCKCR;
+	rpc->gate.bit_idx = 8;
+	rpc->gate.flags = CLK_GATE_SET_TO_DISABLE;
+	rpc->gate.lock = &cpg_lock;
+
+	rpc->csn.reg = base + CPG_RPCCKCR;
+
+	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
+				     &rpc->div.hw,  &clk_divider_ops,
+				     &rpc->gate.hw, &clk_gate_ops, 0);
+	if (IS_ERR(clk))
+		kfree(rpc);
+
+	cpg_simple_notifier_register(notifiers, &rpc->csn);
+	return clk;
+}
+
+struct rpc2_clock {
+	struct clk_fixed_factor fixed;
+	struct clk_gate gate;
+};
+
+static struct clk * __init cpg_rpcd2_clk_register(const char *name,
+						  void __iomem *base,
+						  const char *parent_name)
+{
+	struct rpc2_clock *rpc2;
+	struct clk *clk;
+
+	rpc2 = kzalloc(sizeof(*rpc2), GFP_KERNEL);
+	if (!rpc2)
+		return ERR_PTR(-ENOMEM);
+
+	rpc2->fixed.mult = 1;
+	rpc2->fixed.div = 2;
+
+	rpc2->gate.reg = base + CPG_RPCCKCR;
+	rpc2->gate.bit_idx = 9;
+	rpc2->gate.flags = CLK_GATE_SET_TO_DISABLE;
+	rpc2->gate.lock = &cpg_lock;
+
+	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
+				     &rpc2->fixed.hw, &clk_fixed_factor_ops,
+				     &rpc2->gate.hw, &clk_gate_ops, 0);
+	if (IS_ERR(clk))
+		kfree(rpc2);
+
+	return clk;
+}
+
 
 static const struct rcar_gen3_cpg_pll_config *cpg_pll_config __initdata;
 static unsigned int cpg_clk_extalr __initdata;
@@ -600,6 +684,21 @@ struct clk * __init rcar_gen3_cpg_clk_re
 		}
 		break;
 
+	case CLK_TYPE_GEN3_RPCSRC:
+		return clk_register_divider_table(NULL, core->name,
+						  __clk_get_name(parent), 0,
+						  base + CPG_RPCCKCR, 3, 2, 0,
+						  cpg_rpcsrc_div_table,
+						  &cpg_lock);
+
+	case CLK_TYPE_GEN3_RPC:
+		return cpg_rpc_clk_register(core->name, base,
+					    __clk_get_name(parent), notifiers);
+
+	case CLK_TYPE_GEN3_RPCD2:
+		return cpg_rpcd2_clk_register(core->name, base,
+					      __clk_get_name(parent));
+
 	default:
 		return ERR_PTR(-EINVAL);
 	}
Index: renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.h
===================================================================
--- renesas-drivers.orig/drivers/clk/renesas/rcar-gen3-cpg.h
+++ renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.h
@@ -23,6 +23,9 @@ enum rcar_gen3_clk_types {
 	CLK_TYPE_GEN3_Z2,
 	CLK_TYPE_GEN3_OSC,	/* OSC EXTAL predivider and fixed divider */
 	CLK_TYPE_GEN3_RCKSEL,	/* Select parent/divider using RCKCR.CKSEL */
+	CLK_TYPE_GEN3_RPCSRC,
+	CLK_TYPE_GEN3_RPC,
+	CLK_TYPE_GEN3_RPCD2,
 
 	/* SoC specific definitions start here */
 	CLK_TYPE_GEN3_SOC_BASE,
@@ -57,6 +60,7 @@ struct rcar_gen3_cpg_pll_config {
 	u8 osc_prediv;
 };
 
+#define CPG_RPCCKCR	0x238
 #define CPG_RCKCR	0x240
 
 struct clk *rcar_gen3_cpg_clk_register(struct device *dev,