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.bur...@imgtec.com>
---
Changes in v2:
- New patch
drivers/clk/Kconfig | 8 +++
drivers/clk/Makefile | 1 +
drivers/clk/clk_boston.c | 96 ++++++++++++++++++++++++++++++++
include/dt-bindings/clock/boston-clock.h | 13 +++++
4 files changed, 118 insertions(+)
create mode 100644 drivers/clk/clk_boston.c
create mode 100644 include/dt-bindings/clock/boston-clock.h
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 6eee8eb..85eea0d 100644
--- 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/uniphier/Kconfig"
source "drivers/clk/exynos/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index f7a8891..9d14122 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
obj-$(CONFIG_CLK_UNIPHIER) += uniphier/
obj-$(CONFIG_CLK_EXYNOS) += exynos/
+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
index 0000000..dbbb05b
--- /dev/null
+++ b/drivers/clk/clk_boston.c
@@ -0,0 +1,96 @@
+/*
+ * 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 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;
+
+#define EXT(field) ((mmcmdiv & field) >> (ffs(field) - 1))
+
+ in_rate = EXT(BOSTON_PLAT_MMCMDIV_INPUT);
+ mul = EXT(BOSTON_PLAT_MMCMDIV_MUL);
+
+ switch (clk->id) {
+ case BOSTON_CLK_SYS:
+ div = EXT(BOSTON_PLAT_MMCMDIV_CLK0DIV);
+ break;
+ case BOSTON_CLK_CPU:
+ div = EXT(BOSTON_PLAT_MMCMDIV_CLK1DIV);
+ break;
+ default:
+ return 0;
+ }
+
+#undef EXT
+
+ 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
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__ */
--
2.9.0
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