Add a driver for the clocks provided by the MIPS Boston board from
Imagination Technologies. 2 clocks are provided - the system clock & the
CPU clock - and each is a simple fixed rate clock whose frequency can be
determined by reading a register provided by the board.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Cc: linux-clk@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
---
Changes in v5:
- Use struct clk_hw rather than struct clk.
- Comment on reasoning for use of CLK_OF_DECLARE.
- Drop depends on OF from Kconfig.
- Define pr_fmt to get clearer error messages.
Changes in v4:
- Adjust to expect the parent node to be the syscon.
- Update MAINTAINERS entry.
Changes in v3: None
Changes in v2:
- Support BOSTON_CLK_INPUT.
- Register clocks with clk_register_fixed_rate during boot, removing need for clk_ops.
- s/uint32_t/u32/.
- Move driver to a vendor directory.
MAINTAINERS | 1 +
drivers/clk/Kconfig | 1 +
drivers/clk/Makefile | 1 +
drivers/clk/imgtec/Kconfig | 9 ++++
drivers/clk/imgtec/Makefile | 1 +
drivers/clk/imgtec/clk-boston.c | 103 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 116 insertions(+)
create mode 100644 drivers/clk/imgtec/Kconfig
create mode 100644 drivers/clk/imgtec/Makefile
create mode 100644 drivers/clk/imgtec/clk-boston.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 6a341862f5d6..2749877a4574 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8503,6 +8503,7 @@ M: Paul Burton <paul.burton@xxxxxxxxxx>
L: linux-mips@xxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/clock/img,boston-clock.txt
+F: drivers/clk/imgtec/clk-boston.c
F: include/dt-bindings/clock/boston-clock.h
MIROSOUND PCM20 FM RADIO RECEIVER DRIVER
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 36cfea38135f..251a22139e73 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -219,6 +219,7 @@ config COMMON_CLK_VC5
source "drivers/clk/bcm/Kconfig"
source "drivers/clk/hisilicon/Kconfig"
+source "drivers/clk/imgtec/Kconfig"
source "drivers/clk/mediatek/Kconfig"
source "drivers/clk/meson/Kconfig"
source "drivers/clk/mvebu/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index c19983afcb81..a4a7c5df8b93 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -59,6 +59,7 @@ obj-y += bcm/
obj-$(CONFIG_ARCH_BERLIN) += berlin/
obj-$(CONFIG_H8300) += h8300/
obj-$(CONFIG_ARCH_HISI) += hisilicon/
+obj-y += imgtec/
obj-$(CONFIG_ARCH_MXC) += imx/
obj-$(CONFIG_MACH_INGENIC) += ingenic/
obj-$(CONFIG_COMMON_CLK_KEYSTONE) += keystone/
diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig
new file mode 100644
index 000000000000..f6dcb748e9c4
--- /dev/null
+++ b/drivers/clk/imgtec/Kconfig
@@ -0,0 +1,9 @@
+config COMMON_CLK_BOSTON
+ bool "Clock driver for MIPS Boston boards"
+ depends on MIPS || COMPILE_TEST
+ select MFD_SYSCON
+ ---help---
+ Enable this to support the system & CPU clocks on the MIPS Boston
+ development board from Imagination Technologies. These are simple
+ fixed rate clocks whose rate is determined by reading a platform
+ provided register.
diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile
new file mode 100644
index 000000000000..ac779b8c22f2
--- /dev/null
+++ b/drivers/clk/imgtec/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_COMMON_CLK_BOSTON) += clk-boston.o
diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
new file mode 100644
index 000000000000..f18f10351785
--- /dev/null
+++ b/drivers/clk/imgtec/clk-boston.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2016-2017 Imagination Technologies
+ * Author: Paul Burton <paul.burton@xxxxxxxxxx>
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) "clk-boston: " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/clock/boston-clock.h>
+
+#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)
+
+#define BOSTON_CLK_COUNT 3
+
+static u32 ext_field(u32 val, u32 mask)
+{
+ return (val & mask) >> (ffs(mask) - 1);
+}
+
+static void __init clk_boston_setup(struct device_node *np)
+{
+ unsigned long in_freq, cpu_freq, sys_freq;
+ uint mmcmdiv, mul, cpu_div, sys_div;
+ struct clk_hw_onecell_data *onecell;
+ struct regmap *regmap;
+ struct clk_hw *hw;
+ int err;
+
+ regmap = syscon_node_to_regmap(np->parent);
+ if (IS_ERR(regmap)) {
+ pr_err("failed to find regmap\n");
+ return;
+ }
+
+ err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
+ if (err) {
+ pr_err("failed to read mmcm_div register: %d\n", err);
+ return;
+ }
+
+ in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
+ mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
+
+ sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
+ sys_freq = mult_frac(in_freq, mul, sys_div);
+
+ cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
+ cpu_freq = mult_frac(in_freq, mul, cpu_div);
+
+ onecell = kzalloc(sizeof(*onecell) +
+ (BOSTON_CLK_COUNT * sizeof(struct clk_hw *)),
+ GFP_KERNEL);
+ if (!onecell)
+ return;
+
+ onecell->num = BOSTON_CLK_COUNT;
+
+ hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
+ if (IS_ERR(hw)) {
+ pr_err("failed to register input clock: %ld\n", PTR_ERR(hw));
+ return;
+ }
+ onecell->hws[BOSTON_CLK_INPUT] = hw;
+
+ hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
+ if (IS_ERR(hw)) {
+ pr_err("failed to register sys clock: %ld\n", PTR_ERR(hw));
+ return;
+ }
+ onecell->hws[BOSTON_CLK_SYS] = hw;
+
+ hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
+ if (IS_ERR(hw)) {
+ pr_err("failed to register cpu clock: %ld\n", PTR_ERR(hw));
+ return;
+ }
+ onecell->hws[BOSTON_CLK_CPU] = hw;
+
+ err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell);
+ if (err)
+ pr_err("failed to add DT provider: %d\n", err);
+}
+
+/*
+ * Use CLK_OF_DECLARE so that this driver is probed early enough to provide the
+ * CPU frequency for use with the GIC or cop0 counters/timers.
+ */
+CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);
--
2.13.1
