Subject: [sodaville] [PATCH 1/6] i2c/pxa2xx: Don't touch ISAR on X86

From: [email-masked] (Ben Dooks)
Date: Mon, 06 Dec 2010 04:40:18 +0000

On 04/12/10 18:22, Sebastian Andrzej Siewior wrote:
> * Sebastian Andrzej Siewior | 2010-12-03 19:17:04 [+0100]:
> 
>> Ben Dooks wrote:
>>>> +#ifndef CONFIG_X86
>>>>  	writel(i2c->slave_addr, _ISAR(i2c));
>>>> +#endif
>>
>>
>>> I'd prefer some way of changing based on either the device name (see
>>> some other drivers which bind on multiple names) to define things such
>>> as this, as well as possibly changing the register layout.
>>
>> Do you want me to also change the register access? This would be a
>> intrusive patch since I would have to touch every readl()/writel() line
>> in this file.
> I've been looking at the wrong code while writting this. Here are two
> variants. -variant2 containts the size using this patch. variant1 uses
> 
>  #define _IBMR(i2c)     ((i2c)->reg_base + pxa_reg_layout[(i2c)->layout].ibmr)
> 
> for the access.
> 
>     text    data     bss     dec     hex filename
>     3753      84       0    3837     efd i2c-pxa-org.o
>     4017      84       0    4101    1005 i2c-pxa-variant1.o
>     3525      84       0    3609     e19 i2c-pxa-variant2.o
> 
> Are you fine with this?
> 
> Signed-off-by: Sebastian Andrzej Siewior <[email-masked]>
> ---
>  drivers/i2c/busses/i2c-pxa.c |   64 +++++++++++++++++++++++++++++++----------
>  1 files changed, 48 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index f4c19a9..29ff876 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -38,17 +38,40 @@
>  #include <asm/irq.h>
>  #include <plat/i2c.h>
>  
> -/*
> - * I2C register offsets will be shifted 0 or 1 bit left, depending on
> - * different SoCs
> - */
> -#define REG_SHIFT_0	(0 << 0)
> -#define REG_SHIFT_1	(1 << 0)
> -#define REG_SHIFT(d)	((d) & 0x1)
> +
> +struct pxa_reg_layout {
> +	u32 ibmr;
> +	u32 idbr;
> +	u32 icr;
> +	u32 isr;
> +	u32 isar;
> +};
> +
> +enum pxa_i2c_types {
> +	REGS_PXA2XX,
> +	REGS_PXA3XX,
> +};
> +
> +static struct pxa_reg_layout pxa_reg_layout[] = {
> +	[REGS_PXA2XX] = {
> +		.ibmr =	0x00,
> +		.idbr =	0x10,
> +		.icr =	0x20,
> +		.isr =	0x30,
> +		.isar =	0x40,
> +
> +	}, [REGS_PXA3XX] = {
> +		.ibmr =	0x00,
> +		.idbr =	0x08,
> +		.icr =	0x10,
> +		.isr =	0x18,
> +		.isar =	0x20,
> +	},
> +};
>  
>  static const struct platform_device_id i2c_pxa_id_table[] = {
> -	{ "pxa2xx-i2c",		REG_SHIFT_1 },
> -	{ "pxa3xx-pwri2c",	REG_SHIFT_0 },
> +	{ "pxa2xx-i2c",		REGS_PXA2XX },
> +	{ "pxa3xx-pwri2c",	REGS_PXA3XX },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
> @@ -111,7 +134,11 @@ struct pxa_i2c {
>  	u32			icrlog[32];
>  
>  	void __iomem		*reg_base;
> -	unsigned int		reg_shift;
> +	void __iomem		*reg_ibmr;
> +	void __iomem		*reg_idbr;
> +	void __iomem		*reg_icr;
> +	void __iomem		*reg_isr;
> +	void __iomem		*reg_isar;
>  
>  	unsigned long		iobase;
>  	unsigned long		iosize;
> @@ -121,11 +148,11 @@ struct pxa_i2c {
>  	unsigned int		fast_mode :1;
>  };
>  
> -#define _IBMR(i2c)	((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
> -#define _IDBR(i2c)	((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
> -#define _ICR(i2c)	((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
> -#define _ISR(i2c)	((i2c)->reg_base + (0xc << (i2c)->reg_shift))
> -#define _ISAR(i2c)	((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
> +#define _IBMR(i2c)	((i2c)->reg_ibmr)
> +#define _IDBR(i2c)	((i2c)->reg_idbr)
> +#define _ICR(i2c)	((i2c)->reg_icr)
> +#define _ISR(i2c)	((i2c)->reg_isr)
> +#define _ISAR(i2c)	((i2c)->reg_isar)
>  
>  /*
>   * I2C Slave mode address
> @@ -1044,7 +1071,12 @@ static int i2c_pxa_probe(struct platform_device *dev)
>  		ret = -EIO;
>  		goto eremap;
>  	}
> -	i2c->reg_shift = REG_SHIFT(id->driver_data);
> +
> +	i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[id->driver_data].ibmr;
> +	i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[id->driver_data].idbr;
> +	i2c->reg_icr = i2c->reg_base + pxa_reg_layout[id->driver_data].icr;
> +	i2c->reg_isr = i2c->reg_base + pxa_reg_layout[id->driver_data].isr;
> +	i2c->reg_isar = i2c->reg_base + pxa_reg_layout[id->driver_data].isar;
>  
>  	i2c->iobase = res->start;
>  	i2c->iosize = resource_size(res);

Ok, this seems to be looking good.

I'll hold this for a few days before a final decision. will add to -next
tomorrow.