clk: shmobile: Add R8A7740-specific clock support

Driver for the R8A7740's clocks that are too specific to be supported by a generic driver.

Signed-off-by Ulrich Hecht <[email protected]>

Acked-by Geert Uytterhoeven <[email protected]>

Acked-by Laurent Pinchart <[email protected]>

---

Changes since v4:
- marked bindings as experimental
- added acks

Changes since v3:
- removed excess element in struct initializer
- use of_clk_get_parent_name() instead of hardcoding extal2
- fixed wrong parent index for extalr
- reformatted register addresses

Changes since v2:
- added missing clock extal2
- removed redundant divider mask

Changes since v1:
- reshuffled to include DT bindings and Makefile changes

 .../bindings/clock/renesas,r8a7740-cpg-clocks.txt  |  41 +++++
 drivers/clk/shmobile/Makefile                      |   1 +
 drivers/clk/shmobile/clk-r8a7740.c                 | 199 +++++++++++++++++++++
 3 files changed, 241 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt
 create mode 100644 drivers/clk/shmobile/clk-r8a7740.c

Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt new file +41 -0

new file mode 100644
index 0000000..2c03302
@@ -0,0 +1,41 @@
+These bindings should be considered EXPERIMENTAL for now.
+
+* Renesas R8A7740  Clock Pulse Generator (CPG)
+
+The CPG generates core clocks for the R8A7740 SoC. It includes three PLLs
+and several fixed ratio and variable ratio dividers.
+
+Required Properties:
+
+  - compatible: Must be "renesas,r8a7740-cpg-clocks"
+
+  - reg: Base address and length of the memory resource used by the CPG
+
+  - clocks: Reference to the three parent clocks
+  - #clock-cells: Must be 1
+  - clock-output-names: The names of the clocks. Supported clocks are
+    "system", "pllc0", "pllc1", "pllc2", "r", "usb24s", "i", "zg", "b",
+    "m1", "hp", "hpp", "usbp", "s", "zb", "m3", and "cp".
+
+  - renesas,mode: board-specific settings of the MD_CK* bits
+
+
+Example
+-------
+
+cpg_clocks: cpg_clocks at e6150000 {
+        compatible = "renesas,r8a7740-cpg-clocks";
+        reg = <0xe6150000 0x10000>;
+        clocks = <&extal1_clk>, <&extal2_clk>, <&extalr_clk>;
+        #clock-cells = <1>;
+        clock-output-names = "system", "pllc0", "pllc1",
+                             "pllc2", "r",
+                             "usb24s",
+                             "i", "zg", "b", "m1", "hp",
+                             "hpp", "usbp", "s", "zb", "m3",
+                             "cp";
+};
+
+&cpg_clocks {
+       renesas,mode = <0x05>;
+};

drivers/clk/shmobile/Makefile +1 -0

index 5404cb9..20388e8 100644
@@ -1,5 +1,6 @@
 obj-$(CONFIG_ARCH_EMEV2)               += clk-emev2.o
 obj-$(CONFIG_ARCH_R7S72100)            += clk-rz.o
+obj-$(CONFIG_ARCH_R8A7740)             += clk-r8a7740.o
 obj-$(CONFIG_ARCH_R8A7790)             += clk-rcar-gen2.o
 obj-$(CONFIG_ARCH_R8A7791)             += clk-rcar-gen2.o
 obj-$(CONFIG_ARCH_SHMOBILE_MULTI)      += clk-div6.o

drivers/clk/shmobile/clk-r8a7740.c new file +199 -0

new file mode 100644
index 0000000..1e2eaae
@@ -0,0 +1,199 @@
+/*
+ * r8a7740 Core CPG Clocks
+ *
+ * Copyright (C) 2014  Ulrich Hecht
+ *
+ * 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>
+
+struct r8a7740_cpg {
+       struct clk_onecell_data data;
+       spinlock_t lock;
+       void __iomem *reg;
+};
+
+#define CPG_FRQCRA     0x00
+#define CPG_FRQCRB     0x04
+#define CPG_PLLC2CR    0x2c
+#define CPG_USBCKCR    0x8c
+#define CPG_FRQCRC     0xe0
+
+#define CLK_ENABLE_ON_INIT BIT(0)
+
+struct div4_clk {
+       const char *name;
+       unsigned int reg;
+       unsigned int shift;
+       int flags;
+};
+
+static struct div4_clk div4_clks[] = {
+       { "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
+       { "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
+       { "b", CPG_FRQCRA,  8, CLK_ENABLE_ON_INIT },
+       { "m1", CPG_FRQCRA,  4, CLK_ENABLE_ON_INIT },
+       { "hp", CPG_FRQCRB,  4, 0 },
+       { "hpp", CPG_FRQCRC, 20, 0 },
+       { "usbp", CPG_FRQCRC, 16, 0 },
+       { "s", CPG_FRQCRC, 12, 0 },
+       { "zb", CPG_FRQCRC,  8, 0 },
+       { "m3", CPG_FRQCRC,  4, 0 },
+       { "cp", CPG_FRQCRC,  0, 0 },
+       { NULL, 0, 0, 0 },
+};
+
+static const struct clk_div_table div4_div_table[] = {
+       { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
+       { 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
+       { 13, 72 }, { 14, 96 }, { 0, 0 }
+};
+
+static u32 cpg_mode __initdata;
+
+static struct clk * __init
+r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
+                            const char *name)
+{
+       const struct clk_div_table *table = NULL;
+       const char *parent_name;
+       unsigned int shift, reg;
+       unsigned int mult = 1;
+       unsigned int div = 1;
+
+       if (!strcmp(name, "r")) {
+               switch (cpg_mode & (BIT(2) | BIT(1))) {
+               case BIT(1) | BIT(2):
+                       /* extal1 */
+                       parent_name = of_clk_get_parent_name(np, 0);
+                       div = 2048;
+                       break;
+               case BIT(2):
+                       /* extal1 */
+                       parent_name = of_clk_get_parent_name(np, 0);
+                       div = 1024;
+                       break;
+               default:
+                       /* extalr */
+                       parent_name = of_clk_get_parent_name(np, 2);
+                       break;
+               }
+       } else if (!strcmp(name, "system")) {
+               parent_name = of_clk_get_parent_name(np, 0);
+               if (cpg_mode & BIT(1))
+                       div = 2;
+       } else if (!strcmp(name, "pllc0")) {
+               /* PLLC0/1 are configurable multiplier clocks. Register them as
+                * fixed factor clocks for now as there's no generic multiplier
+                * clock implementation and we currently have no need to change
+                * the multiplier value.
+                */
+               u32 value = clk_readl(cpg->reg + CPG_FRQCRC);
+               parent_name = "system";
+               mult = ((value >> 24) & 0x7f) + 1;
+       } else if (!strcmp(name, "pllc1")) {
+               u32 value = clk_readl(cpg->reg + CPG_FRQCRA);
+               parent_name = "system";
+               mult = ((value >> 24) & 0x7f) + 1;
+               div = 2;
+       } else if (!strcmp(name, "pllc2")) {
+               u32 value = clk_readl(cpg->reg + CPG_PLLC2CR);
+               parent_name = "system";
+               mult = ((value >> 24) & 0x3f) + 1;
+       } else if (!strcmp(name, "usb24s")) {
+               u32 value = clk_readl(cpg->reg + CPG_USBCKCR);
+               if (value & BIT(7))
+                       /* extal2 */
+                       parent_name = of_clk_get_parent_name(np, 1);
+               else
+                       parent_name = "system";
+               if (!(value & BIT(6)))
+                       div = 2;
+       } else {
+               struct div4_clk *c;
+               for (c = div4_clks; c->name; c++) {
+                       if (!strcmp(name, c->name)) {
+                               parent_name = "pllc1";
+                               table = div4_div_table;
+                               reg = c->reg;
+                               shift = c->shift;
+                               break;
+                       }
+               }
+               if (!c->name)
+                       return ERR_PTR(-EINVAL);
+       }
+
+       if (!table) {
+               return clk_register_fixed_factor(NULL, name, parent_name, 0,
+                                                mult, div);
+       } else {
+               return clk_register_divider_table(NULL, name, parent_name, 0,
+                                                 cpg->reg + reg, shift, 4, 0,
+                                                 table, &cpg->lock);
+       }
+}
+
+static void __init r8a7740_cpg_clocks_init(struct device_node *np)
+{
+       struct r8a7740_cpg *cpg;
+       struct clk **clks;
+       unsigned int i;
+       int num_clks;
+
+       if (of_property_read_u32(np, "renesas,mode", &cpg_mode))
+               pr_warn("%s: missing renesas,mode property\n", __func__);
+
+       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(num_clks * 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.
+                */
+               return;
+       }
+
+       spin_lock_init(&cpg->lock);
+
+       cpg->data.clks = clks;
+       cpg->data.clk_num = num_clks;
+
+       cpg->reg = of_iomap(np, 0);
+       if (WARN_ON(cpg->reg == NULL))
+               return;
+
+       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 = r8a7740_cpg_register_clock(np, cpg, 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(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
+              r8a7740_cpg_clocks_init);

Signature · 1 line

1.8.4.5

Quoting Ulrich Hecht (2014-05-23 06:27:15)

Quoted 6 lines

Driver for the R8A7740's clocks that are too specific to be supported by a generic driver.

Signed-off-by Ulrich Hecht <[email protected]>

Acked-by Geert Uytterhoeven <[email protected]>

Acked-by Laurent Pinchart <[email protected]>

Taken into clk-next.

[ Cc ARM-SoC Maintainers <[email protected]> ]

Quoted 9 lines · Mike Turquette

Quoting Ulrich Hecht (2014-05-23 06:27:15)

Quoted 6 lines

Driver for the R8A7740's clocks that are too specific to be supported by a generic driver.

Signed-off-by Ulrich Hecht <[email protected]>

Acked-by Geert Uytterhoeven <[email protected]>

Acked-by Laurent Pinchart <[email protected]>

Taken into clk-next.

Thanks Mike!

I would like to queue-up integration patches that depend on this one. Ideally for v3.17.

Do you expect this patch to appear in v3.16-rc1? If not would it be possible for you to provide a branch with stable commit ids that I could use as a base?

Quoting Simon Horman (2014-05-25 17:37:16)

Quoted 15 lines

[ Cc ARM-SoC Maintainers <[email protected]> ]

Quoted 9 lines · Mike Turquette

Quoting Ulrich Hecht (2014-05-23 06:27:15)

Quoted 6 lines

Driver for the R8A7740's clocks that are too specific to be supported by a generic driver.

Signed-off-by Ulrich Hecht <[email protected]>

Acked-by Geert Uytterhoeven <[email protected]>

Acked-by Laurent Pinchart <[email protected]>

Taken into clk-next.

Thanks Mike!

Quoted 6 lines

I would like to queue-up integration patches that depend on this one. Ideally for v3.17.

Do you expect this patch to appear in v3.16-rc1? If not would it be possible for you to provide a branch with stable commit ids that I could use as a base?

I will submit this patch towards 3.16-rc1 when the merge window opens.