[PATCH v4 5/6] clk: bd71837: Add driver for BD71837 PMIC clock

Matti Vaittinen
2018-05-30T08:43:33Z

Support BD71837 gateable 32768 Hz clock.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
drivers/clk/Kconfig | 9 +++
drivers/clk/Makefile | 1 +
drivers/clk/clk-bd71837.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 161 insertions(+)
create mode 100644 drivers/clk/clk-bd71837.c

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 41492e980ef4..4b045699bb5e 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -279,6 +279,15 @@ config COMMON_CLK_STM32H7
---help---
Support for stm32h7 SoC family clocks

+config COMMON_CLK_BD71837
+ tristate "Clock driver for ROHM BD71837 PMIC MFD"
+ depends on MFD_BD71837
+ depends on I2C=y
+ depends on OF
+ help
+ This driver supports ROHM BD71837 PMIC clock.
+
+
source "drivers/clk/bcm/Kconfig"
source "drivers/clk/hisilicon/Kconfig"
source "drivers/clk/imgtec/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index de6d06ac790b..8393c4af7d5a 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -21,6 +21,7 @@ endif
obj-$(CONFIG_MACH_ASM9260) += clk-asm9260.o
obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
obj-$(CONFIG_ARCH_AXXIA) += clk-axm5516.o
+obj-$(CONFIG_COMMON_CLK_BD71837) += clk-bd71837.o
obj-$(CONFIG_COMMON_CLK_CDCE706) += clk-cdce706.o
obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
diff --git a/drivers/clk/clk-bd71837.c b/drivers/clk/clk-bd71837.c
new file mode 100644
index 000000000000..91456d1077ac
--- /dev/null
+++ b/drivers/clk/clk-bd71837.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 ROHM Semiconductors
+// bd71837.c -- ROHM BD71837MWV clock driver
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mfd/bd71837.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+static int bd71837_clk_enable(struct clk_hw *hw);
+static void bd71837_clk_disable(struct clk_hw *hw);
+static int bd71837_clk_is_enabled(struct clk_hw *hw);
+
+struct bd71837_clk {
+ struct clk_hw hw;
+ uint8_t reg;
+ uint8_t mask;
+ unsigned long rate;
+ struct platform_device *pdev;
+ struct bd71837 *mfd;
+};
+
+static unsigned long bd71837_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate);
+
+static const struct clk_ops bd71837_clk_ops = {
+ .recalc_rate = &bd71837_clk_recalc_rate,
+ .prepare = &bd71837_clk_enable,
+ .unprepare = &bd71837_clk_disable,
+ .is_prepared = &bd71837_clk_is_enabled,
+};
+
+static int bd71837_clk_set(struct clk_hw *hw, int status)
+{
+ struct bd71837_clk *c = container_of(hw, struct bd71837_clk, hw);
+
+ return bd71837_update_bits(c->mfd, c->reg, c->mask, status);
+}
+
+static void bd71837_clk_disable(struct clk_hw *hw)
+{
+ int rv;
+ struct bd71837_clk *c = container_of(hw, struct bd71837_clk, hw);
+
+ rv = bd71837_clk_set(hw, 0);
+ if (rv)
+ dev_err(&c->pdev->dev, "Failed to disable 32K clk (%d)\n", rv);
+}
+
+static int bd71837_clk_enable(struct clk_hw *hw)
+{
+ return bd71837_clk_set(hw, 1);
+}
+
+static int bd71837_clk_is_enabled(struct clk_hw *hw)
+{
+ struct bd71837_clk *c = container_of(hw, struct bd71837_clk, hw);
+
+ return c->mask & bd71837_reg_read(c->mfd, c->reg);
+}
+
+static unsigned long bd71837_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct bd71837_clk *c = container_of(hw, struct bd71837_clk, hw);
+
+ return c->rate;
+}
+
+static int bd71837_clk_probe(struct platform_device *pdev)
+{
+ struct bd71837_clk *c;
+ int rval = -ENOMEM;
+ struct bd71837 *mfd = dev_get_drvdata(pdev->dev.parent);
+ const char *errstr = "memory allocation for bd71837 data failed";
+ struct clk_init_data init = {
+ .name = "bd71837-32k-out",
+ .ops = &bd71837_clk_ops,
+ };
+
+ c = kzalloc(sizeof(struct bd71837_clk), GFP_KERNEL);
+ if (!c)
+ goto err_out;
+
+ c->reg = BD71837_REG_OUT32K;
+ c->mask = BD71837_OUT32K_EN;
+ c->rate = BD71837_CLK_RATE;
+ c->mfd = mfd;
+ c->pdev = pdev;
+
+ if (pdev->dev.of_node)
+ of_property_read_string_index(pdev->dev.of_node,
+ "clock-output-names", 0,
+ &init.name);
+
+ c->hw.init = &init;
+
+ errstr = "failed to register 32K clk";
+ rval = clk_hw_register(&pdev->dev, &c->hw);
+ if (rval)
+ goto err_free;
+
+ errstr = "failed to register clkdev for bd71837";
+ rval = clk_hw_register_clkdev(&c->hw, init.name, NULL);
+ if (rval)
+ goto err_unregister;
+
+ platform_set_drvdata(pdev, c);
+ dev_dbg(&pdev->dev, "bd71837_clk successfully probed\n");
+
+ return 0;
+
+err_unregister:
+ clk_hw_unregister(&c->hw);
+err_free:
+ kfree(c);
+err_out:
+ dev_err(&pdev->dev, "%s\n", errstr);
+ return rval;
+}
+
+static int bd71837_clk_remove(struct platform_device *pdev)
+{
+ struct bd71837_clk *c = platform_get_drvdata(pdev);
+
+ if (c) {
+ clk_hw_unregister(&c->hw);
+ kfree(c);
+ platform_set_drvdata(pdev, NULL);
+ }
+ return 0;
+}
+
+static struct platform_driver bd71837_clk = {
+ .driver = {
+ .name = "bd71837-clk",
+ },
+ .probe = bd71837_clk_probe,
+ .remove = bd71837_clk_remove,
+};
+
+module_platform_driver(bd71837_clk);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("BD71837 chip clk driver");
+MODULE_LICENSE("GPL");
--
2.14.3