diff options
Diffstat (limited to 'drivers/platform/chrome/cros_ec_spi.c')
| -rw-r--r-- | drivers/platform/chrome/cros_ec_spi.c | 80 |
1 files changed, 74 insertions, 6 deletions
diff --git a/drivers/platform/chrome/cros_ec_spi.c b/drivers/platform/chrome/cros_ec_spi.c index ffc38f9d4829..8e9451720e73 100644 --- a/drivers/platform/chrome/cros_ec_spi.c +++ b/drivers/platform/chrome/cros_ec_spi.c @@ -75,6 +75,27 @@ struct cros_ec_spi { unsigned int end_of_msg_delay; }; +typedef int (*cros_ec_xfer_fn_t) (struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg); + +/** + * struct cros_ec_xfer_work_params - params for our high priority workers + * + * @work: The work_struct needed to queue work + * @fn: The function to use to transfer + * @ec_dev: ChromeOS EC device + * @ec_msg: Message to transfer + * @ret: The return value of the function + */ + +struct cros_ec_xfer_work_params { + struct work_struct work; + cros_ec_xfer_fn_t fn; + struct cros_ec_device *ec_dev; + struct cros_ec_command *ec_msg; + int ret; +}; + static void debug_packet(struct device *dev, const char *name, u8 *ptr, int len) { @@ -350,13 +371,13 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev, } /** - * cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply + * do_cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply * * @ec_dev: ChromeOS EC device * @ec_msg: Message to transfer */ -static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, - struct cros_ec_command *ec_msg) +static int do_cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg) { struct ec_host_response *response; struct cros_ec_spi *ec_spi = ec_dev->priv; @@ -493,13 +514,13 @@ exit: } /** - * cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply + * do_cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply * * @ec_dev: ChromeOS EC device * @ec_msg: Message to transfer */ -static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, - struct cros_ec_command *ec_msg) +static int do_cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg) { struct cros_ec_spi *ec_spi = ec_dev->priv; struct spi_transfer trans; @@ -611,6 +632,53 @@ exit: return ret; } +static void cros_ec_xfer_high_pri_work(struct work_struct *work) +{ + struct cros_ec_xfer_work_params *params; + + params = container_of(work, struct cros_ec_xfer_work_params, work); + params->ret = params->fn(params->ec_dev, params->ec_msg); +} + +static int cros_ec_xfer_high_pri(struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg, + cros_ec_xfer_fn_t fn) +{ + struct cros_ec_xfer_work_params params; + + INIT_WORK_ONSTACK(¶ms.work, cros_ec_xfer_high_pri_work); + params.ec_dev = ec_dev; + params.ec_msg = ec_msg; + params.fn = fn; + + /* + * This looks a bit ridiculous. Why do the work on a + * different thread if we're just going to block waiting for + * the thread to finish? The key here is that the thread is + * running at high priority but the calling context might not + * be. We need to be at high priority to avoid getting + * context switched out for too long and the EC giving up on + * the transfer. + */ + queue_work(system_highpri_wq, ¶ms.work); + flush_work(¶ms.work); + destroy_work_on_stack(¶ms.work); + + return params.ret; +} + +static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg) +{ + return cros_ec_xfer_high_pri(ec_dev, ec_msg, do_cros_ec_pkt_xfer_spi); +} + +static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, + struct cros_ec_command *ec_msg) +{ + return cros_ec_xfer_high_pri(ec_dev, ec_msg, do_cros_ec_cmd_xfer_spi); +} + static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev) { struct device_node *np = dev->of_node; |