[PATCH v4 01/19] clk: shmobile: r8a7779: Add clocks support
Simon Horman
horms+renesas at verge.net.au
Thu Mar 13 04:59:44 EDT 2014
The R8A7779 SoC has several clocks that are too custom to be supported in a
generic driver. Those clocks are all fixed rate clocks with multiplier and
divisor set according to boot mode configuration.
Based on work for R-Car Gen2 SoCs by Laurent Pinchart.
Cc: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
Cc: devicetree at vger.kernel.org
Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
---
Under discussion
* Laurent Pinchart would like an "renesas,rcar-gen1-cpg-clocks" compat string
added. I am less enthusiastic.
v4
* As suggested by Geert Uytterhoeven
- Remove double and from bindings documentation
- Remove unused CPG_PLL_CONFIG_INDEX and struct cpg_pll_config
- Correct order of cpg_clk_configs entries
* As suggested by Laurent Pinchart
- Update copyright to include 2014
- Remove reference to non-existent divider clocks in changelog
- Do not map cpg->reg as it is not accessed
- Return an error for unknown name values in r8a7779_cpg_register_clock()
- Expose clkb in binding
- Do not include MSPT registers in register range in binding example
* Write (BIT(2)|BIT(1)) instead of (BIT(1)|BIT(2)) as it is less confusing
(to me)
v3
* As suggested by Laurent Pinchart
- Added external clock input
- Use PLLA ratio set bu MD11 and MD12
- Add _div suffixes of fields of struct cpt_clk_config
- Register PLLA as a fixed factor clock
- Use sizeof() instead of sizeof
- Use num_clks instead of CPG_NUM_CLOCKS in r8a7779_cpg_clocks_init()
- I kept this as r8a7779 binding rather than moving to a R-Car Gen1
binding which could be shared with other SoCs as I do not believe that
the SoCs is are sufficiently similar.
---
.../bindings/clock/renesas,r8a7779-cpg-clocks.txt | 27 +++
drivers/clk/shmobile/Makefile | 1 +
drivers/clk/shmobile/clk-r8a7779.c | 181 +++++++++++++++++++++
include/linux/clk/shmobile.h | 3 +
4 files changed, 212 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/renesas,r8a7779-cpg-clocks.txt
create mode 100644 drivers/clk/shmobile/clk-r8a7779.c
diff --git a/Documentation/devicetree/bindings/clock/renesas,r8a7779-cpg-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,r8a7779-cpg-clocks.txt
new file mode 100644
index 0000000..ed3c8cb
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,r8a7779-cpg-clocks.txt
@@ -0,0 +1,27 @@
+* Renesas R8A7779 Clock Pulse Generator (CPG)
+
+The CPG generates core clocks for the R8A7779. It includes one PLL and
+several fixed ratio dividers
+
+Required Properties:
+
+ - compatible: Must be "renesas,r8a7779-cpg-clocks"
+ - reg: Base address and length of the memory resource used by the CPG
+
+ - clocks: Reference to the parent clock
+ - #clock-cells: Must be 1
+ - clock-output-names: The names of the clocks. Supported clocks are "plla",
+ "z", "zs", "s", "s1", "p", "b", "out".
+
+
+Example
+-------
+
+ cpg_clocks: cpg_clocks at ffc80000 {
+ compatible = "renesas,r8a7779-cpg-clocks";
+ reg = <0 0xffc80000 0 0x30>;
+ clocks = <&extal_clk>;
+ #clock-cells = <1>;
+ clock-output-names = "plla", "z", "zs", "s", "s1", "p",
+ "b", "out";
+ };
diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile
index 9ecef14..2121ba0 100644
--- a/drivers/clk/shmobile/Makefile
+++ b/drivers/clk/shmobile/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_ARCH_EMEV2) += clk-emev2.o
+obj-$(CONFIG_ARCH_R8A7779) += clk-r8a7779.o
obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o
obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o
obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-div6.o
diff --git a/drivers/clk/shmobile/clk-r8a7779.c b/drivers/clk/shmobile/clk-r8a7779.c
new file mode 100644
index 0000000..8974a41
--- /dev/null
+++ b/drivers/clk/shmobile/clk-r8a7779.c
@@ -0,0 +1,181 @@
+/*
+ * r8a7779 Core CPG Clocks
+ *
+ * Copyright (C) 2013, 2014 Horms Solutions Ltd.
+ *
+ * Contact: Simon Horman <horms at verge.net.au>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/shmobile.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+#include <dt-bindings/clock/r8a7779-clock.h>
+
+#define CPG_NUM_CLOCKS (R8A7779_CLK_OUT + 1)
+
+struct r8a7779_cpg {
+ struct clk_onecell_data data;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+/* -----------------------------------------------------------------------------
+ * CPG Clock Data
+ */
+
+/*
+ * MD1 = 1 MD1 = 0
+ * (PLLA = 1500) (PLLA = 1600)
+ * (MHz) (MHz)
+ *------------------------------------------------+--------------------
+ * clkz 1000 (2/3) 800 (1/2)
+ * clkzs 250 (1/6) 200 (1/8)
+ * clki 750 (1/2) 800 (1/2)
+ * clks 250 (1/6) 200 (1/8)
+ * clks1 125 (1/12) 100 (1/16)
+ * clks3 187.5 (1/8) 200 (1/8)
+ * clks4 93.7 (1/16) 100 (1/16)
+ * clkp 62.5 (1/24) 50 (1/32)
+ * clkg 62.5 (1/24) 66.6 (1/24)
+ * clkb, CLKOUT
+ * (MD2 = 0) 62.5 (1/24) 66.6 (1/24)
+ * (MD2 = 1) 41.6 (1/36) 50 (1/32)
+ */
+
+#define CPG_CLK_CONFIG_INDEX(md) (((md) & (BIT(2)|BIT(1))) >> 1)
+
+struct cpg_clk_config {
+ unsigned int z_mult;
+ unsigned int z_div;
+ unsigned int zs_and_s_div;
+ unsigned int s1_div;
+ unsigned int p_div;
+ unsigned int b_and_out_div;
+};
+
+static const struct cpg_clk_config cpg_clk_configs[4] __initconst = {
+ { 1, 2, 8, 16, 32, 24 },
+ { 2, 3, 6, 12, 24, 24 },
+ { 1, 2, 8, 16, 32, 32 },
+ { 2, 3, 6, 12, 24, 36 },
+};
+
+/*
+ * MD PLLA Ratio
+ * 12 11
+ *------------------------
+ * 0 0 x42
+ * 0 1 x48
+ * 1 0 x56
+ * 1 1 x64
+ */
+
+#define CPG_PLLA_MULT_INDEX(md) (((md) & (BIT(12)|BIT(11))) >> 11)
+
+static const unsigned int cpg_plla_mult[4] __initconst = { 42, 48, 56, 64 };
+
+/* -----------------------------------------------------------------------------
+ * Initialization
+ */
+
+static u32 cpg_mode __initdata;
+
+static struct clk * __init
+r8a7779_cpg_register_clock(struct device_node *np, struct r8a7779_cpg *cpg,
+ const struct cpg_clk_config *config,
+ unsigned int plla_mult, const char *name)
+{
+ const char *parent_name = "plla";
+ unsigned int mult = 1;
+ unsigned int div = 1;
+
+ if (!strcmp(name, "plla")) {
+ parent_name = of_clk_get_parent_name(np, 0);
+ mult = plla_mult;
+ } else if (!strcmp(name, "z")) {
+ div = config->z_div;
+ mult = config->z_mult;
+ } else if (!strcmp(name, "zs") || !strcmp(name, "s")) {
+ div = config->zs_and_s_div;
+ } else if (!strcmp(name, "s1")) {
+ div = config->s1_div;
+ } else if (!strcmp(name, "p")) {
+ div = config->p_div;
+ } else if (!strcmp(name, "b") || !strcmp(name, "out")) {
+ div = config->b_and_out_div;
+ } else {
+ return ERR_PTR(-EINVAL);
+ }
+
+ return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, div);
+}
+
+static void __init r8a7779_cpg_clocks_init(struct device_node *np)
+{
+ const struct cpg_clk_config *config;
+ struct r8a7779_cpg *cpg;
+ struct clk **clks;
+ unsigned int i, plla_mult;
+ int num_clks;
+
+ num_clks = of_property_count_strings(np, "clock-output-names");
+ if (num_clks < 0) {
+ pr_err("%s: failed to count clocks\n", __func__);
+ return;
+ }
+
+ cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
+ clks = kzalloc(CPG_NUM_CLOCKS * sizeof(*clks), GFP_KERNEL);
+ if (cpg == NULL || clks == NULL) {
+ /* We're leaking memory on purpose, there's no point in cleaning
+ * up as the system won't boot anyway.
+ */
+ pr_err("%s: failed to allocate cpg\n", __func__);
+ return;
+ }
+
+ spin_lock_init(&cpg->lock);
+
+ cpg->data.clks = clks;
+ cpg->data.clk_num = num_clks;
+
+ config = &cpg_clk_configs[CPG_CLK_CONFIG_INDEX(cpg_mode)];
+ plla_mult = cpg_plla_mult[CPG_PLLA_MULT_INDEX(cpg_mode)];
+
+ for (i = 0; i < num_clks; ++i) {
+ const char *name;
+ struct clk *clk;
+
+ of_property_read_string_index(np, "clock-output-names", i,
+ &name);
+
+ clk = r8a7779_cpg_register_clock(np, cpg, config,
+ plla_mult, name);
+ if (IS_ERR(clk))
+ pr_err("%s: failed to register %s %s clock (%ld)\n",
+ __func__, np->name, name, PTR_ERR(clk));
+ else
+ cpg->data.clks[i] = clk;
+ }
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+}
+CLK_OF_DECLARE(r8a7779_cpg_clks, "renesas,r8a7779-cpg-clocks",
+ r8a7779_cpg_clocks_init);
+
+void __init r8a7779_clocks_init(u32 mode)
+{
+ cpg_mode = mode;
+
+ of_clk_init(NULL);
+}
diff --git a/include/linux/clk/shmobile.h b/include/linux/clk/shmobile.h
index f9bf080..9f8a140 100644
--- a/include/linux/clk/shmobile.h
+++ b/include/linux/clk/shmobile.h
@@ -1,7 +1,9 @@
/*
* Copyright 2013 Ideas On Board SPRL
+ * Copyright 2013, 2014 Horms Solutions Ltd.
*
* Contact: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
+ * Contact: Simon Horman <horms at verge.net.au>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -14,6 +16,7 @@
#include <linux/types.h>
+void r8a7779_clocks_init(u32 mode);
void rcar_gen2_clocks_init(u32 mode);
#endif
--
1.8.5.2
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