linux-kernel - Re: [PATCH 2/3] drm/bridge: ti-sn65dsi86: add debugfs

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Message-ID: <20190704123511.GG6569@pendragon.ideasonboard.com>
Date:   Thu, 4 Jul 2019 15:35:11 +0300
From:   Laurent Pinchart <laurent.pinchart@...asonboard.com>
To:     Andrzej Hajda <a.hajda@...sung.com>
Cc:     Rob Clark <robdclark@...il.com>, dri-devel@...ts.freedesktop.org,
        linux-arm-msm@...r.kernel.org, Sean Paul <seanpaul@...omium.org>,
        Rob Clark <robdclark@...omium.org>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] drm/bridge: ti-sn65dsi86: add debugfs

Hello,

On Thu, Jul 04, 2019 at 02:31:20PM +0200, Andrzej Hajda wrote:
> On 02.07.2019 17:44, Rob Clark wrote:
> > From: Rob Clark <robdclark@...omium.org>
> >
> > Add a debugfs file to show status registers.
> >
> > Signed-off-by: Rob Clark <robdclark@...omium.org>
> > ---
> >  drivers/gpu/drm/bridge/ti-sn65dsi86.c | 42 +++++++++++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > index f1a2493b86d9..a6f27648c015 100644
> > --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> > @@ -5,6 +5,7 @@
> >   */
> >  
> >  #include <linux/clk.h>
> > +#include <linux/debugfs.h>
> >  #include <linux/gpio/consumer.h>
> >  #include <linux/i2c.h>
> >  #include <linux/iopoll.h>
> > @@ -109,6 +110,7 @@ struct ti_sn_bridge {
> >  	struct drm_dp_aux		aux;
> >  	struct drm_bridge		bridge;
> >  	struct drm_connector		connector;
> > +	struct dentry			*debugfs;
> >  	struct device_node		*host_node;
> >  	struct mipi_dsi_device		*dsi;
> >  	struct clk			*refclk;
> > @@ -178,6 +180,42 @@ static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
> >  	SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
> >  };
> >  
> > +static int status_show(struct seq_file *s, void *data)
> > +{
> > +	struct ti_sn_bridge *pdata = s->private;
> > +	unsigned int reg, val;
> > +
> > +	seq_puts(s, "STATUS REGISTERS:\n");

NO NEED TO SHOUT :-)

> > +
> > +	pm_runtime_get_sync(pdata->dev);
> > +
> > +	/* IRQ Status Registers, see Table 31 in datasheet */
> > +	for (reg = 0xf0; reg <= 0xf8; reg++) {
> > +		regmap_read(pdata->regmap, reg, &val);
> > +		seq_printf(s, "[0x%02x] = 0x%08x\n", reg, val);
> > +	}
> > +
> > +	pm_runtime_put(pdata->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +DEFINE_SHOW_ATTRIBUTE(status);
> > +
> > +static void ti_sn_debugfs_init(struct ti_sn_bridge *pdata)
> > +{
> > +	pdata->debugfs = debugfs_create_dir("ti_sn65dsi86", NULL);
> 
> If some day we will have board with two such bridges there will be a
> problem.

Could we use the platform device name for this ?

> Anyway:
> 
> Reviewed-by: Andrzej Hajda <a.hajda@...sung.com>
> 
> > +
> > +	debugfs_create_file("status", 0600, pdata->debugfs, pdata,
> > +			&status_fops);
> > +}
> > +
> > +static void ti_sn_debugfs_remove(struct ti_sn_bridge *pdata)
> > +{
> > +	debugfs_remove_recursive(pdata->debugfs);
> > +	pdata->debugfs = NULL;
> > +}
> > +

You need to conditionally-compile this based on CONFIG_DEBUG_FS.

> >  /* Connector funcs */
> >  static struct ti_sn_bridge *
> >  connector_to_ti_sn_bridge(struct drm_connector *connector)
> > @@ -869,6 +907,8 @@ static int ti_sn_bridge_probe(struct i2c_client *client,
> >  
> >  	drm_bridge_add(&pdata->bridge);
> >  
> > +	ti_sn_debugfs_init(pdata);
> > +
> >  	return 0;
> >  }
> >  
> > @@ -879,6 +919,8 @@ static int ti_sn_bridge_remove(struct i2c_client *client)
> >  	if (!pdata)
> >  		return -EINVAL;
> >  
> > +	ti_sn_debugfs_remove(pdata);
> > +
> >  	of_node_put(pdata->host_node);
> >  
> >  	pm_runtime_disable(pdata->dev);

-- 
Regards,

Laurent Pinchart