clk: boston: Providea simple driver for Boston board clocks

Add a simple driver for the clocks provided by the MIPS Boston
development board. The system provides information about 2 clocks whose
rates are fixed by the bitfile flashed in the boards FPGA, and this
driver simply reads the rates of these 2 clocks.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 8f3b96a97362268a346e6da11a74adeb82c3c479..c05ce2a9efa384034bc5773ffe5cc83b11a500f8 100644 (file)
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -20,6 +20,14 @@ config SPL_CLK
          setting up clocks within SPL, and allows the same drivers to be
          used as U-Boot proper.
 
+config CLK_BOSTON
+       def_bool y if TARGET_BOSTON
+       depends on CLK
+       select REGMAP
+       select SYSCON
+       help
+         Enable this to support the clocks
+
 source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
 source "drivers/clk/exynos/Kconfig"

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 778d7486f066c9934e47e62817499914b9ccb120..40a5e8cae868d8e579b9488e2ec88267bf668956 100644 (file)
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -15,3 +15,4 @@ obj-y += tegra/
 obj-$(CONFIG_CLK_UNIPHIER) += uniphier/
 obj-$(CONFIG_CLK_EXYNOS) += exynos/
 obj-$(CONFIG_CLK_AT91) += at91/
+obj-$(CONFIG_CLK_BOSTON) += clk_boston.o

diff --git a/drivers/clk/clk_boston.c b/drivers/clk/clk_boston.c
new file mode 100644 (file)
index 0000000..78f1b75
--- /dev/null
+++ b/drivers/clk/clk_boston.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#include <common.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <dt-bindings/clock/boston-clock.h>
+#include <regmap.h>
+#include <syscon.h>
+
+struct clk_boston {
+       struct regmap *regmap;
+};
+
+#define BOSTON_PLAT_MMCMDIV            0x30
+# define BOSTON_PLAT_MMCMDIV_CLK0DIV   (0xff << 0)
+# define BOSTON_PLAT_MMCMDIV_INPUT     (0xff << 8)
+# define BOSTON_PLAT_MMCMDIV_MUL       (0xff << 16)
+# define BOSTON_PLAT_MMCMDIV_CLK1DIV   (0xff << 24)
+
+static uint32_t ext_field(uint32_t val, uint32_t mask)
+{
+       return (val & mask) >> (ffs(mask) - 1);
+}
+
+static ulong clk_boston_get_rate(struct clk *clk)
+{
+       struct clk_boston *state = dev_get_platdata(clk->dev);
+       uint32_t in_rate, mul, div;
+       uint mmcmdiv;
+       int err;
+
+       err = regmap_read(state->regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
+       if (err)
+               return 0;
+
+       in_rate = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT);
+       mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
+
+       switch (clk->id) {
+       case BOSTON_CLK_SYS:
+               div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
+               break;
+       case BOSTON_CLK_CPU:
+               div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
+               break;
+       default:
+               return 0;
+       }
+
+       return (in_rate * mul * 1000000) / div;
+}
+
+const struct clk_ops clk_boston_ops = {
+       .get_rate = clk_boston_get_rate,
+};
+
+static int clk_boston_ofdata_to_platdata(struct udevice *dev)
+{
+       struct clk_boston *state = dev_get_platdata(dev);
+       struct udevice *syscon;
+       int err;
+
+       err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
+                                          "regmap", &syscon);
+       if (err) {
+               error("unable to find syscon device\n");
+               return err;
+       }
+
+       state->regmap = syscon_get_regmap(syscon);
+       if (!state->regmap) {
+               error("unable to find regmap\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static const struct udevice_id clk_boston_match[] = {
+       {
+               .compatible = "img,boston-clock",
+       },
+       { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(clk_boston) = {
+       .name = "boston_clock",
+       .id = UCLASS_CLK,
+       .of_match = clk_boston_match,
+       .ofdata_to_platdata = clk_boston_ofdata_to_platdata,
+       .platdata_auto_alloc_size = sizeof(struct clk_boston),
+       .ops = &clk_boston_ops,
+};

diff --git a/include/dt-bindings/clock/boston-clock.h b/include/dt-bindings/clock/boston-clock.h
new file mode 100644 (file)
index 0000000..25f9cd2
--- /dev/null
+++ b/include/dt-bindings/clock/boston-clock.h
@@ -0,0 +1,13 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__
+#define __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__
+
+#define BOSTON_CLK_SYS 0
+#define BOSTON_CLK_CPU 1
+
+#endif /* __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__ */