[U-Boot] [PATCH 16/24] mxc_i2c: prep work for multiple busses support

[Marek Vasut]

Dear Troy Kisky,

> Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>
> ---
>  drivers/i2c/mxc_i2c.c |  121
> ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 100
> insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
> index cb061f7..ec05798 100644
> --- a/drivers/i2c/mxc_i2c.c
> +++ b/drivers/i2c/mxc_i2c.c
> @@ -58,9 +58,7 @@ struct mxc_i2c_regs {
>  #define I2SR_IIF	(1 << 1)
>  #define I2SR_RX_NO_AK	(1 << 0)
> 
> -#ifdef CONFIG_SYS_I2C_BASE
> -#define I2C_BASE	CONFIG_SYS_I2C_BASE
> -#else
> +#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
>  #error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
>  #endif
> 
> @@ -114,11 +112,11 @@ static uint8_t i2c_imx_get_clk(unsigned int rate)
>  }
> 
>  /*
> - * Init I2C Bus
> + * Set I2C Bus speed
>   */
> -void i2c_init(int speed, int unused)
> +int bus_i2c_set_bus_speed(void *base, int speed)
>  {
> -	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
> +	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
>  	u8 clk_idx = i2c_imx_get_clk(speed);
>  	u8 idx = i2c_clk_div[clk_idx][1];
> 
> @@ -128,23 +126,15 @@ void i2c_init(int speed, int unused)
>  	/* Reset module */
>  	writeb(0, &i2c_regs->i2cr);
>  	writeb(0, &i2c_regs->i2sr);
> -}
> -
> -/*
> - * Set I2C Speed
> - */
> -int i2c_set_bus_speed(unsigned int speed)
> -{
> -	i2c_init(speed, 0);
>  	return 0;
>  }
> 
>  /*
>   * Get I2C Speed
>   */
> -unsigned int i2c_get_bus_speed(void)
> +unsigned int bus_i2c_get_bus_speed(void *base)
>  {
> -	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
> +	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
>  	u8 clk_idx = readb(&i2c_regs->ifdr);
>  	u8 clk_div;
> 
> @@ -282,12 +272,13 @@ static int i2c_init_transfer(struct mxc_i2c_regs
> *i2c_regs, /*
>   * Read data from I2C device
>   */
> -int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
> +int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
> +		int len)
>  {
> -	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
>  	int ret;
>  	unsigned int temp;
>  	int i;
> +	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
> 
>  	ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
>  	if (ret)
> @@ -338,11 +329,12 @@ int i2c_read(uchar chip, uint addr, int alen, uchar
> *buf, int len) /*
>   * Write data to I2C device
>   */
> -int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
> +int bus_i2c_write(void *base, uchar chip, uint addr, int alen, uchar *buf,
> +		int len)
>  {
> -	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
>  	int ret;
>  	int i;
> +	struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
> 
>  	ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
>  	if (ret)
> @@ -359,10 +351,97 @@ int i2c_write(uchar chip, uint addr, int alen, uchar
> *buf, int len) return ret;
>  }
> 
> +typedef void (*toggle_i2c_fn)(void *p);

I really don't like this kind of stuff ... who's supposed to look for this 
typedefs. It makes the code not obviously clear.

> +#ifdef CONFIG_I2C_MULTI_BUS
> +static unsigned g_bus;
> +#else
> +#define g_bus 0
> +#endif
> +
> +struct i2c_parms {
> +	void *base;
> +	void *toggle_data;
> +	toggle_i2c_fn toggle_fn;
> +};
> +
> +struct i2c_parms g_parms[3];
> +
> +void *get_base(void)

static? Or this is part of i2c api?

> +{
> +#ifndef CONFIG_SYS_I2C_BASE
> +	return g_parms[g_bus].base;
> +#elif defined(CONFIG_I2C_MULTI_BUS)
> +	void *ret = g_parms[g_bus].base;
> +	if (!ret)
> +		ret = (void *)CONFIG_SYS_I2C_BASE;
> +	return ret;
> +#else
> +	return (void *)CONFIG_SYS_I2C_BASE;
> +#endif
> +}
> +
> +int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
> +{
> +	return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
> +}
> +
> +int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
> +{
> +	return bus_i2c_write(get_base(), chip, addr, alen, buf, len);
> +}
>  /*
>   * Try if a chip add given address responds (probe the chip)
>   */
>  int i2c_probe(uchar chip)
>  {
> -	return i2c_write(chip, 0, 0, NULL, 0);
> +	return bus_i2c_write(get_base(), chip, 0, 0, NULL, 0);
> +}
> +
> +void bus_i2c_init(void *base, int speed, int unused,
> +		toggle_i2c_fn toggle_fn, void *toggle_data)
> +{
> +	int i = 0;
> +	struct i2c_parms *p = g_parms;
> +	if (!base)
> +		return;
> +	for (;;) {
> +		if (!p->base || (p->base == base)) {
> +			p->base = base;
> +			if (toggle_data) {
> +				p->toggle_data = toggle_data;
> +				p->toggle_fn = toggle_fn;
> +			}
> +			break;
> +		}
> +		p++;
> +		i++;
> +		if (i >= ARRAY_SIZE(g_parms))
> +			return;
> +	}
> +	bus_i2c_set_bus_speed(base, speed);
> +}
> +
> +/*
> + * Init I2C Bus
> + */
> +void i2c_init(int speed, int unused)
> +{
> +	bus_i2c_init(get_base(), speed, unused, NULL, NULL);
> +}
> +
> +/*
> + * Set I2C Speed
> + */
> +int i2c_set_bus_speed(unsigned int speed)
> +{
> +	return bus_i2c_set_bus_speed(get_base(), speed);
> +}
> +
> +/*
> + * Get I2C Speed
> + */
> +unsigned int i2c_get_bus_speed(void)
> +{
> +	return bus_i2c_get_bus_speed(get_base());
>  }