RFC[PATCH 6/6] ARM: S5P64X0: Add clkdev bus lookup support

Subash Patel subashrp at gmail.com
Tue Aug 9 02:03:12 EDT 2011


Hello,

On 08/08/2011 03:51 PM, Sylwester Nawrocki wrote:
> Hello,
>
> On 08/08/2011 10:47 AM, Rajeshwari Shinde wrote:
>> Bus clock alias names created and added to clkdev which will be used
>> by HSMMC driver.
>>
>> Signed-off-by: Rajeshwari Shinde<rajeshwari.s at samsung.com>
>> ---
>>   .../include/mach/s5p64x0-common-sdhci.h            |    2 +
>>   arch/arm/mach-s5p64x0/mach-smdk6440.c              |    5 ++
>>   arch/arm/mach-s5p64x0/mach-smdk6450.c              |    5 ++
>>   arch/arm/mach-s5p64x0/s5p64x0-common-sdhci.c       |    7 +++
>>   arch/arm/plat-samsung/Makefile                     |    1 +
>>   arch/arm/plat-samsung/clkdev-busalias.c            |   44 ++++++++++++++++++++
>>   arch/arm/plat-samsung/include/plat/sdhci.h         |    8 ++++
>>   7 files changed, 72 insertions(+), 0 deletions(-)
>>   create mode 100644 arch/arm/plat-samsung/clkdev-busalias.c
>>
>> diff --git a/arch/arm/mach-s5p64x0/include/mach/s5p64x0-common-sdhci.h b/arch/arm/mach-s5p64x0/include/mach/s5p64x0-common-sdhci.h
>> index a3381f0..b81e6dd 100644
>> --- a/arch/arm/mach-s5p64x0/include/mach/s5p64x0-common-sdhci.h
>> +++ b/arch/arm/mach-s5p64x0/include/mach/s5p64x0-common-sdhci.h
>> @@ -10,6 +10,8 @@
>>
>>   #include<plat/sdhci.h>
>>
>> +extern char *hsmmc_busclksrcs[4];
>> +
>>   extern struct s3c_sdhci_platdata smdk64x0_hsmmc0_pdata;
>>   extern struct s3c_sdhci_platdata smdk64x0_hsmmc1_pdata;
>>   extern struct s3c_sdhci_platdata smdk64x0_hsmmc2_pdata;
>> diff --git a/arch/arm/mach-s5p64x0/mach-smdk6440.c b/arch/arm/mach-s5p64x0/mach-smdk6440.c
>> index 065977f..ad1b49d 100644
>> --- a/arch/arm/mach-s5p64x0/mach-smdk6440.c
>> +++ b/arch/arm/mach-s5p64x0/mach-smdk6440.c
>> @@ -177,6 +177,11 @@ static void __init smdk6440_machine_init(void)
>>   	s3c_sdhci2_set_platdata(&smdk64x0_hsmmc2_pdata);
>>
>>   	platform_add_devices(smdk6440_devices, ARRAY_SIZE(smdk6440_devices));
>> +
>> +	/* create alias for clocks required by SDHCI */
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc0, hsmmc_busclksrcs);
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc1, hsmmc_busclksrcs);
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc2, hsmmc_busclksrcs);
>>   }
>>
>>   MACHINE_START(SMDK6440, "SMDK6440")
>> diff --git a/arch/arm/mach-s5p64x0/mach-smdk6450.c b/arch/arm/mach-s5p64x0/mach-smdk6450.c
>> index 9e6fcef..f3f656e 100644
>> --- a/arch/arm/mach-s5p64x0/mach-smdk6450.c
>> +++ b/arch/arm/mach-s5p64x0/mach-smdk6450.c
>> @@ -196,6 +196,11 @@ static void __init smdk6450_machine_init(void)
>>   	s3c_sdhci2_set_platdata(&smdk64x0_hsmmc2_pdata);
>>
>>   	platform_add_devices(smdk6450_devices, ARRAY_SIZE(smdk6450_devices));
>> +
>> +	/* create alias for clocks required by SDHCI */
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc0, hsmmc_busclksrcs);
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc1, hsmmc_busclksrcs);
>> +	s3c_sdhci_add_busclk_alias(&s3c_device_hsmmc2, hsmmc_busclksrcs);
>>   }
>>
>>   MACHINE_START(SMDK6450, "SMDK6450")
>> diff --git a/arch/arm/mach-s5p64x0/s5p64x0-common-sdhci.c b/arch/arm/mach-s5p64x0/s5p64x0-common-sdhci.c
>> index 03d89f6..9721b2d 100644
>> --- a/arch/arm/mach-s5p64x0/s5p64x0-common-sdhci.c
>> +++ b/arch/arm/mach-s5p64x0/s5p64x0-common-sdhci.c
>> @@ -14,6 +14,13 @@
>>
>>   #include<mach/s5p64x0-common-sdhci.h>
>>
>> +char *hsmmc_busclksrcs[4] = {
>> +	[0] = NULL,
>> +	[1] = NULL,
>> +	[2] = "sclk_mmc", /* mmc bus clock */
>> +	[3] = NULL,
>> +};
Good to use MAX_BUS_CLK instead of 4.
>> +
>>   struct s3c_sdhci_platdata smdk64x0_hsmmc0_pdata __initdata = {
>>   	.cd_type        = S3C_SDHCI_CD_NONE,
>>   	.clk_type       = S3C_SDHCI_CLK_DIV_EXTERNAL,
>> diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile
>> index 853764b..0aae4fa 100644
>> --- a/arch/arm/plat-samsung/Makefile
>> +++ b/arch/arm/plat-samsung/Makefile
>> @@ -31,6 +31,7 @@ obj-$(CONFIG_S3C_ADC)	+= adc.o
>>   # devices
>>
>>   obj-y				+= platformdata.o
>> +obj-y				+= clkdev-busalias.o
>>
>>   obj-$(CONFIG_S3C_DEV_HSMMC)	+= dev-hsmmc.o
>>   obj-$(CONFIG_S3C_DEV_HSMMC1)	+= dev-hsmmc1.o
>> diff --git a/arch/arm/plat-samsung/clkdev-busalias.c b/arch/arm/plat-samsung/clkdev-busalias.c
>> new file mode 100644
>> index 0000000..3e085a2
>> --- /dev/null
>> +++ b/arch/arm/plat-samsung/clkdev-busalias.c
>> @@ -0,0 +1,44 @@
>> +/* linux/arch/arm/plat-samsung/clkdev_busalias.c
>> + *
>> + * Copyright (c) 2011 Simtec Electronics
>> + *	http://www.samsung.com
>
> Is this a correct copyright notice?
>
>> + *
>> + * Helper function to add clkdev bus clocks alias names.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> +*/
>> +
>> +#include<linux/clk.h>
>> +#include<linux/device.h>
>> +#include<linux/types.h>
>> +#include<linux/platform_device.h>
>> +
>> +#include<plat/sdhci.h>
>> +
>> +#define MAX_BUS_CLK (4)
This macro is already defined in drivers/mmc/host/sdhci-s3c.c. Instead 
of redefining it in different places, cant it be moved to some better 
location?
>> +
>> +void s3c_sdhci_add_busclk_alias(struct platform_device *pdev,
>> +				char **mmc_busclks)
>> +{
>> +	int clk_cnt = 0, ptr;
>> +	char devname[14];
>> +
>> +	sprintf(devname, "s3c-sdhci.%d", pdev->id);
>> +
>> +	for (ptr = 0; ptr<  MAX_BUS_CLK; ptr++) {
>> +		char *bus_name = mmc_busclks[ptr];
>> +
>> +		if (bus_name != NULL) {
>> +			char name[14];
>> +			sprintf(name, "mmc_busclk.%d", ptr);
>> +			clk_add_alias(name, devname, bus_name,
>> +					&pdev->dev);
>> +			clk_cnt++;
>> +		}
>> +	}
>> +
>> +	if (clk_cnt == 0)
>> +		dev_err(&pdev->dev, "No MMC bus clocks!");
>> +}
>
>
> Can you explain why these aliases are needed ?
> That seems redundant to me, as the clock 'con_id's could be properly created
> right away when registering the clock with clkdev.
>
I think this aliased name is being used in other place (ref patch 1 in 
this series).

>
>> diff --git a/arch/arm/plat-samsung/include/plat/sdhci.h b/arch/arm/plat-samsung/include/plat/sdhci.h
>> index dde13aa..4933b6a 100644
>> --- a/arch/arm/plat-samsung/include/plat/sdhci.h
>> +++ b/arch/arm/plat-samsung/include/plat/sdhci.h
>> @@ -131,6 +131,14 @@ extern void s5p64x0_setup_sdhci1_cfg_gpio(struct platform_device *, int w);
>>   extern void s5p6440_setup_sdhci2_cfg_gpio(struct platform_device *, int w);
>>   extern void s5p6450_setup_sdhci2_cfg_gpio(struct platform_device *, int w);
>>
>> +/*
>> + * s3c_sdhci_set_busclk - Add alias to bus clocks supported, for clkdev support.
>> + * @pdev: platform device to which the busclks are to be initialised.
>> + * @mmc_busclks: Bus clocks suppored by SDHCI
>> +*/
>> +extern void s3c_sdhci_add_busclk_alias(struct platform_device *pdev,
>> +					char **mmc_busclks);
>> +
>>   /* S3C2416 SDHCI setup */
>>
>>   #ifdef CONFIG_S3C2416_SETUP_SDHCI
>

Regards,
Subash



More information about the linux-arm-kernel mailing list