Re: [PATCH/RFC 2/3] ARM: S5PV310: Add a platform helper for MIPI DSIM/CSIS setup

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

Hello,

On 01/13/2011 02:33 AM, Kukjin Kim wrote:
> Sylwester Nawrocki wrote:
>>
>> MIPI_PHYn_CONTROL registers are shared between MIPI DSIM
>> and MIPI CSIS drivers so a spinlock is used to protect multiple
>> access to these registers. Also a proper state of a common
>> PHY enable bit is maintained in order to avoid a DSIM
>> and CSIS driver conflict.
>>
>> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>  arch/arm/mach-s5pv310/Kconfig                 |    6 ++
>>  arch/arm/mach-s5pv310/Makefile                |    2 +
>>  arch/arm/mach-s5pv310/include/mach/map.h      |    7 +--
>>  arch/arm/mach-s5pv310/include/mach/regs-pmu.h |    6 ++
>>  arch/arm/mach-s5pv310/setup-mipi.c            |   62
>> +++++++++++++++++++++++++
>>  5 files changed, 79 insertions(+), 4 deletions(-)
>>  create mode 100644 arch/arm/mach-s5pv310/setup-mipi.c
>>
>> diff --git a/arch/arm/mach-s5pv310/Kconfig b/arch/arm/mach-s5pv310/Kconfig
>> index b7aa3cd..2420076 100644
>> --- a/arch/arm/mach-s5pv310/Kconfig
>> +++ b/arch/arm/mach-s5pv310/Kconfig
>> @@ -15,6 +15,11 @@ config CPU_S5PV310
>>  	help
>>  	  Enable S5PV310 CPU support
>>
>> +config S5PV310_SETUP_MIPI
>> +	bool
>> +	help
>> +	  Common setup code for MIPI CSIS/DSIM channels 0 and 1.
>> +
>>  config S5PV310_DEV_PD
>>  	bool
>>  	help
>> @@ -96,6 +101,7 @@ config MACH_UNIVERSAL_C210
>>  	select S3C_DEV_HSMMC3
>>  	select S5PV310_SETUP_SDHCI
>>  	select S3C_DEV_I2C1
>> +	select S5PV310_SETUP_MIPI
>>  	select S5PV310_SETUP_I2C1
>>  	help
>>  	  Machine support for Samsung Mobile Universal S5PC210 Reference
>> diff --git a/arch/arm/mach-s5pv310/Makefile
> b/arch/arm/mach-s5pv310/Makefile
>> index 651f193..7f1b89b 100644
>> --- a/arch/arm/mach-s5pv310/Makefile
>> +++ b/arch/arm/mach-s5pv310/Makefile
>> @@ -29,6 +29,8 @@ obj-$(CONFIG_MACH_UNIVERSAL_C210)	+=
> mach-universal_c210.o
>>  # device support
>>
>>  obj-y					+= dev-audio.o
>> +
>> +obj-$(CONFIG_S5PV310_SETUP_MIPI)	+= setup-mipi.o
>>  obj-$(CONFIG_S5PV310_DEV_PD)		+= dev-pd.o
>>
>>  obj-$(CONFIG_S5PV310_SETUP_I2C1)	+= setup-i2c1.o
>> diff --git a/arch/arm/mach-s5pv310/include/mach/map.h b/arch/arm/mach-
>> s5pv310/include/mach/map.h
>> index 33bcff2..6635287 100644
>> --- a/arch/arm/mach-s5pv310/include/mach/map.h
>> +++ b/arch/arm/mach-s5pv310/include/mach/map.h
>> @@ -65,8 +65,7 @@
>>  #define S5PV310_PA_GPIO2		(0x11000000)
>>  #define S5PV310_PA_GPIO3		(0x03860000)
>>
>> -#define S5PV310_PA_MIPI_CSIS0		0x11880000
>> -#define S5PV310_PA_MIPI_CSIS1		0x11890000
>> +#define S5PV310_PA_MIPI_CSIS(x)		(0x11880000 + ((x) *
> 0x10000))
>>
>>  #define S5PV310_PA_HSMMC(x)		(0x12510000 + ((x) * 0x10000))
>>
>> @@ -124,7 +123,7 @@
>>  #define S3C_PA_IIC7			S5PV310_PA_IIC(7)
>>  #define S3C_PA_RTC			S5PV310_PA_RTC
>>  #define S3C_PA_WDT			S5PV310_PA_WATCHDOG
>> -#define S5P_PA_MIPI_CSIS0		S5PV310_PA_MIPI_CSIS0
>> -#define S5P_PA_MIPI_CSIS1		S5PV310_PA_MIPI_CSIS1
>> +#define S5P_PA_MIPI_CSIS0		S5PV310_PA_MIPI_CSIS(0)
>> +#define S5P_PA_MIPI_CSIS1		S5PV310_PA_MIPI_CSIS(1)
>>
>>  #endif /* __ASM_ARCH_MAP_H */
>> diff --git a/arch/arm/mach-s5pv310/include/mach/regs-pmu.h
> b/arch/arm/mach-
>> s5pv310/include/mach/regs-pmu.h
>> index fb333d0..bef8102 100644
>> --- a/arch/arm/mach-s5pv310/include/mach/regs-pmu.h
>> +++ b/arch/arm/mach-s5pv310/include/mach/regs-pmu.h
>> @@ -27,4 +27,10 @@
>>
>>  #define S5P_INT_LOCAL_PWR_EN		0x7
>>
>> +#define S5P_MIPI_PHY0_CONTROL		S5P_PMUREG(0x0710)
>> +#define S5P_MIPI_PHY1_CONTROL		S5P_PMUREG(0x0714)
>> +#define S5P_MIPI_PHY_ENABLE		(1 << 0)
>> +#define S5P_MIPI_PHY_SRESETN		(1 << 1)
>> +#define S5P_MIPI_PHY_MRESETN		(1 << 2)
>> +
>>  #endif /* __ASM_ARCH_REGS_PMU_H */
>> diff --git a/arch/arm/mach-s5pv310/setup-mipi.c b/arch/arm/mach-
>> s5pv310/setup-mipi.c
>> new file mode 100644
>> index 0000000..fc91a29
>> --- /dev/null
>> +++ b/arch/arm/mach-s5pv310/setup-mipi.c
>> @@ -0,0 +1,62 @@
>> +/* linux/arch/arm/mach-s5pv310/setup-mipi.c
>> + *
>> + * Copyright (c) 2010 Samsung Electronics Co., Ltd
>> + *
>> + * S5PV310 - Helper functions for MIPI CSIS/DSIM PHY control
>> + *
>> + * 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/kernel.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/io.h>
>> +#include <linux/spinlock.h>
>> +#include <mach/regs-pmu.h>
>> +
>> +/* Global MIPI CSIS or DSIM PHY enable and reset control. */
>> +static int s5p_mipi_phy_control(struct platform_device *pdev, bool on,
> u32
>> rst)
>> +{
>> +	static DEFINE_SPINLOCK(lock);
>> +	void __iomem *addr;
>> +	unsigned long flags;
>> +	int pid;
>> +	u32 cfg;
>> +
>> +	if (pdev == NULL)
>> +		return -EINVAL;
>> +
>> +	pid = pdev->id;
>> +	if (pid != 0 && pid != 1)
>> +		return -EINVAL;
>> +
>> +	addr = pid ? S5P_MIPI_PHY1_CONTROL : S5P_MIPI_PHY0_CONTROL;
>> +
>> +	spin_lock_irqsave(&lock, flags);
>> +
>> +	cfg = __raw_readl(addr) & ~rst;
>> +	if (on)
>> +		cfg |= rst;
>> +	__raw_writel(cfg, addr);
>> +
>> +	if (on)
>> +		cfg |= S5P_MIPI_PHY_ENABLE;
>> +	else if (!(cfg & (S5P_MIPI_PHY_SRESETN | S5P_MIPI_PHY_MRESETN) &
> ~rst))
>> +		cfg &= ~S5P_MIPI_PHY_ENABLE;
>> +
>> +	__raw_writel(cfg, addr);
>> +
>> +	spin_unlock_irqrestore(&lock, flags);
>> +	return 0;
>> +}
>> +
>> +int s5p_csis_phy_enable(struct platform_device *pdev, bool on)
>> +{
>> +	return s5p_mipi_phy_control(pdev, on, S5P_MIPI_PHY_SRESETN);
>> +}
>> +
>> +int s5p_dsim_phy_enable(struct platform_device *pdev, bool on)
>> +{
>> +	return s5p_mipi_phy_control(pdev, on, S5P_MIPI_PHY_MRESETN);
>> +}
>> --
>> 1.7.3.4
> 
> Basically, it's not good that each machine(SoC) has each own setup-mipi...
> Because it is very similar(almost same)...means can move it in plat-s5p with
> following.
>
> 1. # of MIPI PHY can be calculated by platform device id
> 2. can use same definition of MIPI PHY control address with same name
> re-mapping.
> 

There one serious problem with that approach though, we cannot make a common
kernel binary for multiple archs. When each mach-s5p* has it's own setup code
the is no issue as those files would be compiled with their respective headers.
How do we solve that problem with common code in plat-s5p? Any comments, ideas?

Regards,
Sylwester








-- 
Sylwester Nawrocki
Samsung Poland R&D Center