On 27.02.2018 12:08, Chanwoo Choi wrote:
Hi,
On 2018년 02월 27일 16:11, Andrzej Hajda wrote:
From: Maciej Purski m.purski@samsung.com
Currently MHL chip must be turned on permanently to detect MHL cable. It duplicates micro-USB controller's (MUIC) functionality and consumes unnecessary power. Lets use extcon attached to MUIC to enable MHL chip only if it detects MHL cable.
Signed-off-by: Maciej Purski m.purski@samsung.com Signed-off-by: Andrzej Hajda a.hajda@samsung.com
v5: updated extcon API
This is rework of the patch by Maciej with following changes:
- use micro-USB port bindings to get extcon, instead of extcon property,
- fixed remove sequence,
- fixed extcon get state logic.
Code finding extcon node is hacky IMO, I guess ultimately it should be done via some framework (maybe even extcon), or at least via helper, I hope it can stay as is until the proper solution will be merged.
Signed-off-by: Andrzej Hajda a.hajda@samsung.com
drivers/gpu/drm/bridge/sil-sii8620.c | 97 ++++++++++++++++++++++++++++++++++-- 1 file changed, 94 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c index 9e785b8e0ea2..62b0adabcac2 100644 --- a/drivers/gpu/drm/bridge/sil-sii8620.c +++ b/drivers/gpu/drm/bridge/sil-sii8620.c @@ -17,6 +17,7 @@
#include <linux/clk.h> #include <linux/delay.h> +#include <linux/extcon.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/interrupt.h> @@ -25,6 +26,7 @@ #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> +#include <linux/of_graph.h> #include <linux/regulator/consumer.h> #include <linux/slab.h>
@@ -81,6 +83,10 @@ struct sii8620 { struct edid *edid; unsigned int gen2_write_burst:1; enum sii8620_mt_state mt_state;
- struct extcon_dev *extcon;
- struct notifier_block extcon_nb;
- struct work_struct extcon_wq;
- int cable_state; struct list_head mt_queue; struct { int r_size;
@@ -2175,6 +2181,77 @@ static void sii8620_init_rcp_input_dev(struct sii8620 *ctx) ctx->rc_dev = rc_dev; }
+static void sii8620_cable_out(struct sii8620 *ctx) +{
- disable_irq(to_i2c_client(ctx->dev)->irq);
- sii8620_hw_off(ctx);
+}
+static void sii8620_extcon_work(struct work_struct *work) +{
- struct sii8620 *ctx =
container_of(work, struct sii8620, extcon_wq);- int state = extcon_get_state(ctx->extcon, EXTCON_DISP_MHL);
- if (state == ctx->cable_state)
return;- ctx->cable_state = state;
- if (state > 0)
sii8620_cable_in(ctx);- else
sii8620_cable_out(ctx);+}
+static int sii8620_extcon_notifier(struct notifier_block *self,
unsigned long event, void *ptr)+{
- struct sii8620 *ctx =
container_of(self, struct sii8620, extcon_nb);- schedule_work(&ctx->extcon_wq);
- return NOTIFY_DONE;
+}
+static int sii8620_extcon_init(struct sii8620 *ctx) +{
- struct extcon_dev *edev;
- struct device_node *musb, *muic;
- int ret;
- /* get micro-USB connector node */
- musb = of_graph_get_remote_node(ctx->dev->of_node, 1, -1);
- /* next get micro-USB Interface Controller node */
- muic = of_get_next_parent(musb);
- if (!muic) {
dev_info(ctx->dev, "no extcon found, switching to 'always on' mode\n");return 0;- }
- edev = extcon_find_edev_by_node(muic);
- of_node_put(muic);
- if (IS_ERR(edev)) {
if (PTR_ERR(edev) == -EPROBE_DEFER)return -EPROBE_DEFER;dev_err(ctx->dev, "Invalid or missing extcon\n");return PTR_ERR(edev);- }
- ctx->extcon = edev;
- ctx->extcon_nb.notifier_call = sii8620_extcon_notifier;
- INIT_WORK(&ctx->extcon_wq, sii8620_extcon_work);
- ret = extcon_register_notifier(edev, EXTCON_DISP_MHL, &ctx->extcon_nb);
You better to use devm_extcon_register_notifier().
With devm version I risk that in case of device unbind notification will be called after .remove callback, it seems to me quite dangerous. Or am I missing something?
Regards Andrzej
- if (ret) {
dev_err(ctx->dev, "failed to register notifier for MHL\n");return ret;- }
- return 0;
+}
static inline struct sii8620 *bridge_to_sii8620(struct drm_bridge *bridge) { return container_of(bridge, struct sii8620, bridge); @@ -2307,13 +2384,20 @@ static int sii8620_probe(struct i2c_client *client, if (ret) return ret;
ret = sii8620_extcon_init(ctx);
if (ret < 0) {
dev_err(ctx->dev, "failed to initialize EXTCON\n");return ret;}
i2c_set_clientdata(client, ctx);
ctx->bridge.funcs = &sii8620_bridge_funcs; ctx->bridge.of_node = dev->of_node; drm_bridge_add(&ctx->bridge);
- sii8620_cable_in(ctx);
if (!ctx->extcon)
sii8620_cable_in(ctx);return 0;
} @@ -2322,8 +2406,15 @@ static int sii8620_remove(struct i2c_client *client) { struct sii8620 *ctx = i2c_get_clientdata(client);
- disable_irq(to_i2c_client(ctx->dev)->irq);
- sii8620_hw_off(ctx);
- if (ctx->extcon) {
extcon_unregister_notifier(ctx->extcon, EXTCON_DISP_MHL,&ctx->extcon_nb);Don't need to unregister the notifier if using devm_extcon_register_notifier().
flush_work(&ctx->extcon_wq);if (ctx->cable_state > 0)sii8620_cable_out(ctx);} else {
sii8620_cable_out(ctx);} drm_bridge_remove(&ctx->bridge);
return 0;
If you use the resource managed function (devm_extcon_register_notifier), Looks good to me. Reviewed-by: Chanwoo Choi cw00.choi@samsung.com