[PATCH RFC 09/10] mmc: cmdq-host: add halt support to command queue host

Ritesh Harjani
2016-06-15T13:03:09Z

From: Asutosh Das <asutoshd@codeaurora.org>

Halt can be used in error cases to get control of the
bus. This is used to remove a task from device queue
and/or other recovery mechanisms.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
[riteshh@codeaurora.org: fixed merge conflicts]
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
---
drivers/mmc/host/cmdq_hci.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/drivers/mmc/host/cmdq_hci.c b/drivers/mmc/host/cmdq_hci.c
index 68c8e03..64be0ce 100644
--- a/drivers/mmc/host/cmdq_hci.c
+++ b/drivers/mmc/host/cmdq_hci.c
@@ -29,6 +29,9 @@
#define DCMD_SLOT 31
#define NUM_SLOTS 32

+/* 1 sec */
+#define HALT_TIMEOUT_MS 1000
+
static inline u8 *get_desc(struct cmdq_host *cq_host, u8 tag)
{
return cq_host->desc_base + (tag * cq_host->slot_sz);
@@ -570,11 +573,42 @@ irqreturn_t cmdq_irq(struct mmc_host *mmc, u32 intmask)
cmdq_dumpregs(cq_host);
}

+ if (status & CQIS_HAC) {
+ /* halt is completed, wakeup waiting thread */
+ complete(&cq_host->halt_comp);
+ }
+
out:
return IRQ_HANDLED;
}
EXPORT_SYMBOL(cmdq_irq);

+/* May sleep */
+static int cmdq_halt(struct mmc_host *mmc, bool halt)
+{
+ struct cmdq_host *cq_host = (struct cmdq_host *)mmc_cmdq_private(mmc);
+ u32 val;
+
+ if (halt) {
+ cmdq_writel(cq_host, cmdq_readl(cq_host, CQCTL) | HALT,
+ CQCTL);
+ val = wait_for_completion_timeout(&cq_host->halt_comp,
+ msecs_to_jiffies(HALT_TIMEOUT_MS));
+ /* halt done: re-enable legacy interrupts */
+ if (cq_host->ops->clear_set_irqs)
+ cq_host->ops->clear_set_irqs(mmc, false);
+
+ return val ? 0 : -ETIMEDOUT;
+ } else {
+ if (cq_host->ops->clear_set_irqs)
+ cq_host->ops->clear_set_irqs(mmc, true);
+ cmdq_writel(cq_host, cmdq_readl(cq_host, CQCTL) & ~HALT,
+ CQCTL);
+ }
+
+ return 0;
+}
+
static void cmdq_post_req(struct mmc_host *host, struct mmc_request *mrq,
int err)
{
@@ -597,6 +631,7 @@ static const struct mmc_cmdq_host_ops cmdq_host_ops = {
.disable = cmdq_disable,
.request = cmdq_request,
.post_req = cmdq_post_req,
+ .halt = cmdq_halt,
};

struct cmdq_host *cmdq_pltfm_init(struct platform_device *pdev)