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 --- 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 | 98 ++++++++++++++++++++++++++++++++++-- 1 file changed, 95 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c index 5131bfb94f06..6f40cbc2445e 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>
@@ -78,6 +80,10 @@ 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; @@ -2102,6 +2108,78 @@ static void sii8620_cable_in(struct sii8620 *ctx) enable_irq(to_i2c_client(ctx->dev)->irq); }
+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_graph_get_remote_node(musb, -1, 0); + of_node_put(musb); + + if (!muic) { + dev_info(ctx->dev, "no extcon found, switching to 'always on' mode\n"); + return 0; + } + + edev = extcon_get_edev_by_of_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); + 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); @@ -2201,13 +2279,20 @@ 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; } @@ -2216,9 +2301,16 @@ static int sii8620_remove(struct i2c_client *client) { struct sii8620 *ctx = i2c_get_clientdata(client);
- disable_irq(to_i2c_client(ctx->dev)->irq); + if (ctx->extcon) { + extcon_unregister_notifier(ctx->extcon, EXTCON_DISP_MHL, + &ctx->extcon_nb); + flush_work(&ctx->extcon_wq); + if (ctx->cable_state > 0) + sii8620_cable_out(ctx); + } else { + sii8620_cable_out(ctx); + } drm_bridge_remove(&ctx->bridge); - sii8620_hw_off(ctx);
return 0; }