Passing pointers directly as platform data is fragile and undocumented. Better to create a platform data structure which explicitly documents what is passed to the driver.
Suggested-by: Tomasz Figa <tomasz.f...@gmail.com> [krzk: Update maintainer's entry] Signed-off-by: Krzysztof Kozlowski <k...@kernel.org> --- Changes since v1: 1. Update maintainer's entry. --- MAINTAINERS | 1 + arch/arm/mach-s3c24xx/common.c | 7 ++++++- drivers/clk/samsung/clk-s3c2410-dclk.c | 7 ++++++- include/linux/platform_data/clk-s3c2410.h | 19 +++++++++++++++++++ 4 files changed, 32 insertions(+), 2 deletions(-) create mode 100644 include/linux/platform_data/clk-s3c2410.h diff --git a/MAINTAINERS b/MAINTAINERS index 5675fc9bfa00..81046738cba9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15295,6 +15295,7 @@ F: Documentation/devicetree/bindings/clock/samsung,s5p* F: drivers/clk/samsung/ F: include/dt-bindings/clock/exynos*.h F: include/linux/clk/samsung.h +F: include/linux/platform_data/clk-s3c2410.h SAMSUNG SPI DRIVERS M: Kukjin Kim <kg...@kernel.org> diff --git a/arch/arm/mach-s3c24xx/common.c b/arch/arm/mach-s3c24xx/common.c index 222238e8acbb..c476a673d07f 100644 --- a/arch/arm/mach-s3c24xx/common.c +++ b/arch/arm/mach-s3c24xx/common.c @@ -17,6 +17,7 @@ #include <linux/platform_device.h> #include <linux/delay.h> #include <linux/io.h> +#include <linux/platform_data/clk-s3c2410.h> #include <linux/platform_data/dma-s3c24xx.h> #include <linux/dmaengine.h> #include <linux/clk/samsung.h> @@ -663,13 +664,17 @@ static struct resource s3c2410_dclk_resource[] = { [0] = DEFINE_RES_MEM(0x56000084, 0x4), }; +static struct s3c2410_clk_platform_data s3c_clk_platform_data = { + .modify_misccr = s3c2410_modify_misccr, +}; + struct platform_device s3c2410_device_dclk = { .name = "s3c2410-dclk", .id = 0, .num_resources = ARRAY_SIZE(s3c2410_dclk_resource), .resource = s3c2410_dclk_resource, .dev = { - .platform_data = s3c2410_modify_misccr, + .platform_data = &s3c_clk_platform_data, }, }; #endif diff --git a/drivers/clk/samsung/clk-s3c2410-dclk.c b/drivers/clk/samsung/clk-s3c2410-dclk.c index 3e0f23e8ec21..f5e0a6ba2d12 100644 --- a/drivers/clk/samsung/clk-s3c2410-dclk.c +++ b/drivers/clk/samsung/clk-s3c2410-dclk.c @@ -11,6 +11,7 @@ #include <linux/clk-provider.h> #include <linux/io.h> #include <linux/platform_device.h> +#include <linux/platform_data/clk-s3c2410.h> #include <linux/module.h> #include "clk.h" @@ -89,10 +90,14 @@ static struct clk_hw *s3c24xx_register_clkout(struct device *dev, const char *name, const char **parent_names, u8 num_parents, u8 shift, u32 mask) { + struct s3c2410_clk_platform_data *pdata = dev_get_platdata(dev); struct s3c24xx_clkout *clkout; struct clk_init_data init; int ret; + if (!pdata) + return ERR_PTR(-EINVAL); + /* allocate the clkout */ clkout = kzalloc(sizeof(*clkout), GFP_KERNEL); if (!clkout) @@ -107,7 +112,7 @@ static struct clk_hw *s3c24xx_register_clkout(struct device *dev, clkout->shift = shift; clkout->mask = mask; clkout->hw.init = &init; - clkout->modify_misccr = dev->platform_data; + clkout->modify_misccr = pdata->modify_misccr; ret = clk_hw_register(dev, &clkout->hw); if (ret) diff --git a/include/linux/platform_data/clk-s3c2410.h b/include/linux/platform_data/clk-s3c2410.h new file mode 100644 index 000000000000..7eb1cfa5409b --- /dev/null +++ b/include/linux/platform_data/clk-s3c2410.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2020 Krzysztof Kozlowski <k...@kernel.org> + */ + +#ifndef __LINUX_PLATFORM_DATA_CLK_S3C2410_H_ +#define __LINUX_PLATFORM_DATA_CLK_S3C2410_H_ + +/** + * struct s3c2410_clk_platform_data - platform data for S3C2410 clock driver + * + * @modify_misccr: Function to modify the MISCCR and return the new value + */ +struct s3c2410_clk_platform_data { + unsigned int (*modify_misccr)(unsigned int clr, unsigned int chg); +}; + +#endif /* __LINUX_PLATFORM_DATA_CLK_S3C2410_H_ */ + -- 2.17.1