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Message-ID: <CABxcv=mrmN5Mzt595ZFgGbOoHJWQMwQ1wiCvcHEiWh_79EbJqQ@mail.gmail.com>
Date: Fri, 10 Jun 2016 09:20:44 -0400
From: Javier Martinez Canillas <javier@...hile0.org>
To: Laxman Dewangan <ldewangan@...dia.com>
Cc: Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...eaurora.org>,
Rob Herring <robh+dt@...nel.org>, linux-clk@...r.kernel.org,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] clk: max77620: Add clock driver for MAX77620/MAX20024
Hello Laxman,
On Fri, Jun 10, 2016 at 6:12 AM, Laxman Dewangan <ldewangan@...dia.com> wrote:
> MAXIM MAX77620 is the power management IC with multiple DCDC/LDO(
> regulators, RTC, GPIOs, Watchdog, 32KHz clock source etc.
>
> Add support for controlling the 32KHz clock source via clock
> framework.
>
> Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
> ---
It looks very similar to the max77686 and max77802 drivers (with only
the difference in number of clock outputs), can you use the helpers in
drivers/clk/clk-max-gen.c ?
> drivers/clk/Kconfig | 9 +++
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-max77620.c | 143 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 153 insertions(+)
> create mode 100644 drivers/clk/clk-max77620.c
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 98efbfc..149f813 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -34,6 +34,15 @@ source "drivers/clk/versatile/Kconfig"
> config COMMON_CLK_MAX_GEN
> bool
>
> +config COMMON_CLK_MAX77620
> + tristate "Clock driver for Maxim 77620/MAX20024 MFD"
> + depends on MFD_MAX77620
> + ---help---
> + This driver supports Maxim MAX77620/MAX20024 32KHz crystal
> + oscillator. These multi-function devices have one fixed rate.
> + The clock can be ON and OFF. Say y to make this driver as
> + built-in and m to make it as module.
> +
> config COMMON_CLK_MAX77686
> tristate "Clock driver for Maxim 77686 MFD"
> depends on MFD_MAX77686
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index dcc5e69..8c2de43 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
> obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
> obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
> obj-$(CONFIG_MACH_LOONGSON32) += clk-ls1x.o
> +obj-$(CONFIG_COMMON_CLK_MAX77620) += clk-max77620.o
> obj-$(CONFIG_COMMON_CLK_MAX_GEN) += clk-max-gen.o
> obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
> obj-$(CONFIG_COMMON_CLK_MAX77802) += clk-max77802.o
> diff --git a/drivers/clk/clk-max77620.c b/drivers/clk/clk-max77620.c
> new file mode 100644
> index 0000000..615cf2e
> --- /dev/null
> +++ b/drivers/clk/clk-max77620.c
> @@ -0,0 +1,143 @@
> +/*
> + * Clock driver for Maxim Max77620 device.
> + *
> + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk-provider.h>
> +#include <linux/mfd/max77620.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +struct max77620_clks_info {
> + struct device *dev;
> + struct regmap *rmap;
> + struct clk *clk;
> + struct clk_hw hw;
> +};
> +
> +static struct max77620_clks_info *to_max77620_clks_info(struct clk_hw *hw)
> +{
> + return container_of(hw, struct max77620_clks_info, hw);
> +}
> +
> +static unsigned long max77620_clks_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + return 32768;
> +}
> +
> +static int max77620_clks_prepare(struct clk_hw *hw)
> +{
> + struct max77620_clks_info *mci = to_max77620_clks_info(hw);
> +
> + return regmap_update_bits(mci->rmap, MAX77620_REG_CNFG1_32K,
> + MAX77620_CNFG1_32K_OUT0_EN,
> + MAX77620_CNFG1_32K_OUT0_EN);
> +}
> +
> +static void max77620_clks_unprepare(struct clk_hw *hw)
> +{
> + struct max77620_clks_info *mci = to_max77620_clks_info(hw);
> +
> + regmap_update_bits(mci->rmap, MAX77620_REG_CNFG1_32K,
> + MAX77620_CNFG1_32K_OUT0_EN, 0);
> +}
> +
> +static int max77620_clks_is_prepared(struct clk_hw *hw)
> +{
> + struct max77620_clks_info *mci = to_max77620_clks_info(hw);
> + unsigned int rval;
> + int ret;
> +
> + ret = regmap_read(mci->rmap, MAX77620_REG_CNFG1_32K, &rval);
> + if (ret < 0)
> + return ret;
> +
> + return !!(rval & MAX77620_CNFG1_32K_OUT0_EN);
> +}
> +
> +static struct clk_ops max77620_clks_ops = {
> + .prepare = max77620_clks_prepare,
> + .unprepare = max77620_clks_unprepare,
> + .is_prepared = max77620_clks_is_prepared,
> + .recalc_rate = max77620_clks_recalc_rate,
> +};
> +
> +struct clk_init_data max77620_clk_init_data = {
> + .name = "clk-32k",
> + .ops = &max77620_clks_ops,
> + .flags = CLK_IGNORE_UNUSED,
> +};
> +
Is really needed to ignore this clock if unused? Consumers should
define this clock and enable if needed.
> +static int max77620_clks_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.parent->of_node;
> + struct max77620_clks_info *mci;
> + struct clk *clk;
> + int ret;
> +
> + mci = devm_kzalloc(&pdev->dev, sizeof(*mci), GFP_KERNEL);
> + if (!mci)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, mci);
> +
> + mci->dev = &pdev->dev;
> + mci->rmap = dev_get_regmap(pdev->dev.parent, NULL);
> + if (!mci->rmap) {
> + dev_err(mci->dev, "Failed to get parent regmap\n");
> + return -ENODEV;
> + }
> + mci->hw.init = &max77620_clk_init_data;
> +
> + clk = devm_clk_register(&pdev->dev, &mci->hw);
> + if (IS_ERR(clk)) {
> + ret = PTR_ERR(clk);
> + dev_err(mci->dev, "Fail to register clock: %d\n", ret);
> + return ret;
> + }
> +
> + mci->clk = clk;
> + ret = of_clk_add_provider(np, of_clk_src_simple_get, mci->clk);
> + if (ret < 0)
> + dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int max77620_clks_remove(struct platform_device *pdev)
> +{
> + of_clk_del_provider(pdev->dev.parent->of_node);
> +
> + return 0;
> +}
> +
> +static struct platform_device_id max77620_clks_devtype[] = {
> + { .name = "max77620-clock", },
> + {},
> +};
> +
Your Kconfig symbol is tristate so the driver can be built as a module
but autoload will not work because the driver is not exporting a
module alias.
IOW, you need MODULE_DEVICE_TABLE(platform, max77620_clks_devtype) here.
> +static struct platform_driver max77620_clks_driver = {
> + .driver = {
> + .name = "max77620-clock",
> + },
> + .probe = max77620_clks_probe,
> + .remove = max77620_clks_remove,
> + .id_table = max77620_clks_devtype,
> +};
> +
> +module_platform_driver(max77620_clks_driver);
> +
> +MODULE_DESCRIPTION("Clock driver for Maxim max77620 PMIC Device");
> +MODULE_AUTHOR("Laxman Dewangan <ldewangan@...dia.com>");
> +MODULE_LICENSE("GPL v2");
> --
> 2.1.4
>
> --
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