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authorMichael Zaidman <michael.zaidman@gmail.com>2022-11-06 00:11:48 +0300
committerJiri Kosina <jkosina@suse.cz>2022-11-11 13:09:36 +0300
commit4b3da6853a619a952e8caf2e8393264dd42ffa27 (patch)
tree7292ac52808cd83a06c78dd4fba6e4678ea79587 /drivers/hid
parent728b117e7862b1eb05c3aad3b2f087b26453d56a (diff)
downloadlinux-4b3da6853a619a952e8caf2e8393264dd42ffa27.tar.xz
HID: ft260: wake up device from power saving mode
The FT260 can enter a power saving mode after being idle for longer than 5 seconds. When being woken up from power saving mode by an I2C write request, a possible NACK is not correctly reported by the controller. As a workaround, the driver will issue an I2C status report two times in ft260_xfer_status() after the chip has been idle for more than 5s. Co-developed-by: Enrik Berkhan <Enrik.Berkhan@inka.de> Signed-off-by: Enrik Berkhan <Enrik.Berkhan@inka.de> Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/hid-ft260.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 40fae81386e3..ac133980dfe9 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -31,6 +31,8 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages");
#define FT260_REPORT_MAX_LENGTH (64)
#define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4)
+#define FT260_WAKEUP_NEEDED_AFTER_MS (4800) /* 5s minus 200ms margin */
+
/*
* The ft260 input report format defines 62 bytes for the data payload, but
* when requested 62 bytes, the controller returns 60 and 2 in separate input
@@ -237,6 +239,7 @@ struct ft260_device {
struct completion wait;
struct mutex lock;
u8 write_buf[FT260_REPORT_MAX_LENGTH];
+ unsigned long need_wakeup_at;
u8 *read_buf;
u16 read_idx;
u16 read_len;
@@ -306,6 +309,20 @@ static int ft260_xfer_status(struct ft260_device *dev)
struct ft260_get_i2c_status_report report;
int ret;
+ if (time_is_before_jiffies(dev->need_wakeup_at)) {
+ ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS,
+ (u8 *)&report, sizeof(report));
+ if (unlikely(ret < 0)) {
+ hid_err(hdev, "failed to retrieve status: %d, no wakeup\n",
+ ret);
+ } else {
+ dev->need_wakeup_at = jiffies +
+ msecs_to_jiffies(FT260_WAKEUP_NEEDED_AFTER_MS);
+ ft260_dbg("bus_status %#02x, wakeup\n",
+ report.bus_status);
+ }
+ }
+
ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS,
(u8 *)&report, sizeof(report));
if (unlikely(ret < 0)) {