linux-kernel - Re: [v6] i2c: imx: support slave mode for imx I2C driver

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Date:   Thu, 5 Dec 2019 12:43:46 +0100
From:   Oleksij Rempel <o.rempel@...gutronix.de>
To:     Sascha Hauer <s.hauer@...gutronix.de>, Biwen Li <biwen.li@....com>
Cc:     shawnguo@...nel.org, kernel@...gutronix.de, festevam@...il.com,
        linux-imx@....com, wsa@...-dreams.de, leoyang.li@....com,
        aisheng.dong@....com, xiaoning.wang@....com, xiaobo.xie@....com,
        linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
        jiafei.pan@....com, linux-arm-kernel@...ts.infradead.org,
        laurentiu.tudor@....com
Subject: Re: [v6] i2c: imx: support slave mode for imx I2C driver

Hi,

On 04.12.19 11:00, Sascha Hauer wrote:
> Hi,
> 
> The patch looks ok to me now, but I still do not like the #ifdeffery
> around CONFIG_I2C_SLAVE. With the patch I just sent (You are on Cc:)
> we could apply the following on your patch which makes it more readable
> and increases compile coverage.
> 
> Wolfram, Biwen, what do you think?


RCAR depends on slave:
config I2C_RCAR 

         tristate "Renesas R-Car I2C Controller" 

         depends on ARCH_RENESAS || COMPILE_TEST 

         select I2C_SLAVE
see:
drivers/i2c/busses/i2c-rcar.c

So, I would suggest to do the same in imx.

So far, I tested this patch on iMX6S. It works in one board (i2c-gpio + i2c-imx) and
two board (i2c-imx + i2c-imx) configuration.
Tested-by: Oleksij Rempel <o.rempel@...gutronix.de>


> 
> Sascha
> 
> ---------------------------8<------------------------------
> 
>  From 52f7c2bf59db61d4b27b59ca6404136e3ed77310 Mon Sep 17 00:00:00 2001
> From: Sascha Hauer <s.hauer@...gutronix.de>
> Date: Wed, 4 Dec 2019 10:56:34 +0100
> Subject: [PATCH] fixup! i2c: imx: support slave mode for imx I2C driver
> 
> ---
>   drivers/i2c/busses/i2c-imx.c | 21 ++++++++++-----------
>   1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index 40ccfca600bf..c5d9ae8226cd 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -203,9 +203,7 @@ struct imx_i2c_struct {
>   	struct pinctrl_state *pinctrl_pins_gpio;
>   
>   	struct imx_i2c_dma	*dma;
> -#if IS_ENABLED(CONFIG_I2C_SLAVE)
>   	struct i2c_client	*slave;
> -#endif
>   };
>   
>   static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
> @@ -913,12 +911,10 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
>   
>   	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
>   
> -#if IS_ENABLED(CONFIG_I2C_SLAVE)
>   	if (i2c_imx->slave) {
>   		dev_err(&i2c_imx->adapter.dev, "Please not do operations of master mode in slave mode");
>   		return -EBUSY;
>   	}
> -#endif
>   
>   	result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
>   	if (result < 0)
> @@ -1068,7 +1064,6 @@ static u32 i2c_imx_func(struct i2c_adapter *adapter)
>   		| I2C_FUNC_SMBUS_READ_BLOCK_DATA;
>   }
>   
> -#if IS_ENABLED(CONFIG_I2C_SLAVE)
>   static int i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx)
>   {
>   	int temp;
> @@ -1159,6 +1154,10 @@ static int i2c_imx_reg_slave(struct i2c_client *client)
>   {
>   	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
>   	int ret;
> +
> +	if (!IS_ENABLED(CONFIG_I2C_SLAVE))
> +		return -EINVAL;
> +
>   	if (i2c_imx->slave)
>   		return -EBUSY;
>   
> @@ -1173,6 +1172,9 @@ static int i2c_imx_unreg_slave(struct i2c_client *client)
>   {
>   	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
>   
> +	if (!IS_ENABLED(CONFIG_I2C_SLAVE))
> +		return -EINVAL;
> +
>   	if (!i2c_imx->slave)
>   		return -EINVAL;
>   
> @@ -1188,15 +1190,12 @@ static int i2c_imx_unreg_slave(struct i2c_client *client)
>   
>   	return 0;
>   }
> -#endif
>   
>   static const struct i2c_algorithm i2c_imx_algo = {
>   	.master_xfer	= i2c_imx_xfer,
>   	.functionality	= i2c_imx_func,
> -#if IS_ENABLED(CONFIG_I2C_SLAVE)
>   	.reg_slave	= i2c_imx_reg_slave,
>   	.unreg_slave	= i2c_imx_unreg_slave,
> -#endif
>   };
>   
>   static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
> @@ -1208,10 +1207,10 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
>   
>   	if (status & I2SR_IIF) {
>   		i2c_imx_clr_if_bit(status, i2c_imx);
> -#if IS_ENABLED(CONFIG_I2C_SLAVE)
> -		if (i2c_imx->slave)
> +
> +		if (IS_ENABLED(CONFIG_I2C_SLAVE) && i2c_imx->slave)
>   			return i2c_imx_slave_isr(i2c_imx);
> -#endif
> +
>   		i2c_imx->i2csr = status;
>   		return i2c_imx_master_isr(i2c_imx);
>   	}
> 

Kind regards,
Oleksij Rempel

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