[PATCH 2/2] drm: bridge: dw-mipi-dsi: Switch to regmap support

[Sam Ravnborg]

Hi Jagan

The change to regmap looks nice. But two small comments below,
just some drive-by comments.

	Sam

On Tue, Jan 24, 2023 at 12:16:47AM +0530, Jagan Teki wrote:
> To make debugging easier, switch the driver to use regmap
> from conventional io calls.
> 
> Signed-off-by: Jagan Teki <jagan at edgeble.ai>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 81 ++++++++++++-------
>  1 file changed, 54 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 47bd69d5ac99..62a160af4047 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
>  #include <linux/reset.h>
>  
>  #include <video/mipi_display.h>
> @@ -242,7 +243,7 @@ struct dw_mipi_dsi {
>  	struct mipi_dsi_host dsi_host;
>  	struct drm_bridge *panel_bridge;
>  	struct device *dev;
> -	void __iomem *base;
> +	struct regmap *regmap;
>  
>  	struct clk *pclk;
>  
> @@ -301,12 +302,16 @@ static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge *bridge)
>  
>  static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
>  {
> -	writel(val, dsi->base + reg);
> +	regmap_write(dsi->regmap, reg, val);
>  }
>  
>  static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
>  {
> -	return readl(dsi->base + reg);
> +	u32 val;
> +
> +	regmap_read(dsi->regmap, reg, &val);
> +
> +	return val;
>  }
>  
>  static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
> @@ -332,6 +337,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
>  	if (IS_ERR(bridge))
>  		return PTR_ERR(bridge);
>  
> +	dev_info(host->dev, "Attached device %s\n", device->name);
>  	dsi->panel_bridge = bridge;
>  
>  	drm_bridge_add(&dsi->bridge);
> @@ -400,9 +406,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
>  	int ret;
>  	u32 val, mask;
>  
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, !(val & GEN_CMD_FULL), 1000,
> -				 CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, !(val & GEN_CMD_FULL), 1000,
> +				       CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to get available command FIFO\n");
>  		return ret;
> @@ -411,9 +417,9 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
>  	dsi_write(dsi, DSI_GEN_HDR, hdr_val);
>  
>  	mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, (val & mask) == mask,
> -				 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, (val & mask) == mask,
> +				       1000, CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to write command FIFO\n");
>  		return ret;
> @@ -443,9 +449,9 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi,
>  			len -= pld_data_bytes;
>  		}
>  
> -		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -					 val, !(val & GEN_PLD_W_FULL), 1000,
> -					 CMD_PKT_STATUS_TIMEOUT_US);
> +		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +					       val, !(val & GEN_PLD_W_FULL), 1000,
> +					       CMD_PKT_STATUS_TIMEOUT_US);
>  		if (ret) {
>  			dev_err(dsi->dev,
>  				"failed to get available write payload FIFO\n");
> @@ -466,9 +472,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
>  	u32 val;
>  
>  	/* Wait end of the read operation */
> -	ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -				 val, !(val & GEN_RD_CMD_BUSY),
> -				 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +	ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +				       val, !(val & GEN_RD_CMD_BUSY), 1000,
> +				       CMD_PKT_STATUS_TIMEOUT_US);
>  	if (ret) {
>  		dev_err(dsi->dev, "Timeout during read operation\n");
>  		return ret;
> @@ -476,9 +482,9 @@ static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi,
>  
>  	for (i = 0; i < len; i += 4) {
>  		/* Read fifo must not be empty before all bytes are read */
> -		ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
> -					 val, !(val & GEN_PLD_R_EMPTY),
> -					 1000, CMD_PKT_STATUS_TIMEOUT_US);
> +		ret = regmap_read_poll_timeout(dsi->regmap, DSI_CMD_PKT_STATUS,
> +					       val, !(val & GEN_PLD_R_EMPTY), 1000,
> +					       CMD_PKT_STATUS_TIMEOUT_US);
>  		if (ret) {
>  			dev_err(dsi->dev, "Read payload FIFO is empty\n");
>  			return ret;
> @@ -499,6 +505,9 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
>  	struct mipi_dsi_packet packet;
>  	int ret, nb_bytes;
>  
> +	DRM_INFO("%x %x %x\n", msg->type,
> +		 ((((u8 *)msg->tx_buf)[0] << 8) >> 8),
> +		 ((((u8 *)msg->tx_buf)[1] << 16)) >> 16);
This looks like some debug left-over. If not, then please consider to
use drm_info or dev_info.
>  	ret = mipi_dsi_create_packet(&packet, msg);
>  	if (ret) {
>  		dev_err(dsi->dev, "failed to create packet: %d\n", ret);
> @@ -828,17 +837,18 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
>  	u32 val;
>  	int ret;
>  
> -	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
> +	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENABLECLK |
>  		  PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
This change is not related to the regmap conversion and should be
separated out.

	Sam