[PATCH 35/48] drm: omapdrm: dsi: Make wait_for_bit_change() return a status

[Sebastian Reichel]

Hi,

On Fri, Oct 13, 2017 at 05:59:31PM +0300, Laurent Pinchart wrote:
> The wait_for_bit_change() function returns the value of the bit it
> polls. This requires the caller to compare the return value to the
> expected bit value. As all the existing callers need is to check whether
> the bit has reached the expected value, it's easier to return a boolean
> status from the function.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel at collabora.co.uk>

-- Sebastian

>  drivers/gpu/drm/omapdrm/dss/dsi.c | 31 +++++++++++++++----------------
>  1 file changed, 15 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> index 7fb048023fd0..c94bb6404a69 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> @@ -531,7 +531,7 @@ static void dsi_completion_handler(void *data, u32 mask)
>  	complete((struct completion *)data);
>  }
>  
> -static inline int wait_for_bit_change(struct platform_device *dsidev,
> +static inline bool wait_for_bit_change(struct platform_device *dsidev,
>  		const struct dsi_reg idx, int bitnum, int value)
>  {
>  	unsigned long timeout;
> @@ -542,21 +542,21 @@ static inline int wait_for_bit_change(struct platform_device *dsidev,
>  	t = 100;
>  	while (t-- > 0) {
>  		if (REG_GET(dsidev, idx, bitnum, bitnum) == value)
> -			return value;
> +			return true;
>  	}
>  
>  	/* then loop for 500ms, sleeping for 1ms in between */
>  	timeout = jiffies + msecs_to_jiffies(500);
>  	while (time_before(jiffies, timeout)) {
>  		if (REG_GET(dsidev, idx, bitnum, bitnum) == value)
> -			return value;
> +			return true;
>  
>  		wait = ns_to_ktime(1000 * 1000);
>  		set_current_state(TASK_UNINTERRUPTIBLE);
>  		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
>  	}
>  
> -	return !value;
> +	return false;
>  }
>  
>  static u8 dsi_get_pixel_size(enum omap_dss_dsi_pixel_format fmt)
> @@ -1259,9 +1259,9 @@ static inline int dsi_if_enable(struct platform_device *dsidev, bool enable)
>  	enable = enable ? 1 : 0;
>  	REG_FLD_MOD(dsidev, DSI_CTRL, enable, 0, 0); /* IF_EN */
>  
> -	if (wait_for_bit_change(dsidev, DSI_CTRL, 0, enable) != enable) {
> -			DSSERR("Failed to set dsi_if_enable to %d\n", enable);
> -			return -EIO;
> +	if (!wait_for_bit_change(dsidev, DSI_CTRL, 0, enable)) {
> +		DSSERR("Failed to set dsi_if_enable to %d\n", enable);
> +		return -EIO;
>  	}
>  
>  	return 0;
> @@ -1450,7 +1450,7 @@ static int dsi_pll_enable(struct dss_pll *pll)
>  	/* XXX PLL does not come out of reset without this... */
>  	dispc_pck_free_enable(1);
>  
> -	if (wait_for_bit_change(dsidev, DSI_PLL_STATUS, 0, 1) != 1) {
> +	if (!wait_for_bit_change(dsidev, DSI_PLL_STATUS, 0, 1)) {
>  		DSSERR("PLL not coming out of reset.\n");
>  		r = -ENODEV;
>  		dispc_pck_free_enable(0);
> @@ -2200,7 +2200,7 @@ static int dsi_cio_init(struct platform_device *dsidev)
>  	 * I/O. */
>  	dsi_read_reg(dsidev, DSI_DSIPHY_CFG5);
>  
> -	if (wait_for_bit_change(dsidev, DSI_DSIPHY_CFG5, 30, 1) != 1) {
> +	if (!wait_for_bit_change(dsidev, DSI_DSIPHY_CFG5, 30, 1)) {
>  		DSSERR("CIO SCP Clock domain not coming out of reset.\n");
>  		r = -EIO;
>  		goto err_scp_clk_dom;
> @@ -2248,7 +2248,7 @@ static int dsi_cio_init(struct platform_device *dsidev)
>  	if (r)
>  		goto err_cio_pwr;
>  
> -	if (wait_for_bit_change(dsidev, DSI_COMPLEXIO_CFG1, 29, 1) != 1) {
> +	if (!wait_for_bit_change(dsidev, DSI_COMPLEXIO_CFG1, 29, 1)) {
>  		DSSERR("CIO PWR clock domain not coming out of reset.\n");
>  		r = -ENODEV;
>  		goto err_cio_pwr_dom;
> @@ -2389,7 +2389,7 @@ static int dsi_force_tx_stop_mode_io(struct platform_device *dsidev)
>  	r = FLD_MOD(r, 1, 15, 15);	/* FORCE_TX_STOP_MODE_IO */
>  	dsi_write_reg(dsidev, DSI_TIMING1, r);
>  
> -	if (wait_for_bit_change(dsidev, DSI_TIMING1, 15, 0) != 0) {
> +	if (!wait_for_bit_change(dsidev, DSI_TIMING1, 15, 0)) {
>  		DSSERR("TX_STOP bit not going down\n");
>  		return -EIO;
>  	}
> @@ -2531,10 +2531,9 @@ static int dsi_vc_enable(struct platform_device *dsidev, int channel,
>  
>  	REG_FLD_MOD(dsidev, DSI_VC_CTRL(channel), enable, 0, 0);
>  
> -	if (wait_for_bit_change(dsidev, DSI_VC_CTRL(channel),
> -		0, enable) != enable) {
> -			DSSERR("Failed to set dsi_vc_enable to %d\n", enable);
> -			return -EIO;
> +	if (!wait_for_bit_change(dsidev, DSI_VC_CTRL(channel), 0, enable)) {
> +		DSSERR("Failed to set dsi_vc_enable to %d\n", enable);
> +		return -EIO;
>  	}
>  
>  	return 0;
> @@ -2586,7 +2585,7 @@ static int dsi_vc_config_source(struct platform_device *dsidev, int channel,
>  	dsi_vc_enable(dsidev, channel, 0);
>  
>  	/* VC_BUSY */
> -	if (wait_for_bit_change(dsidev, DSI_VC_CTRL(channel), 15, 0) != 0) {
> +	if (!wait_for_bit_change(dsidev, DSI_VC_CTRL(channel), 15, 0)) {
>  		DSSERR("vc(%d) busy when trying to config for VP\n", channel);
>  		return -EIO;
>  	}
> -- 
> Regards,
> 
> Laurent Pinchart
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
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