Hi,
On 6/17/2016 2:21 PM, Shawn Lin wrote:
在 2016/6/15 21:01, Ritesh Harjani 写道:
From: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
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.
where to ues it? cmdq_irq or sdhci_irq?
Below cmdq_halt will be used by higher
layers to get legacy bus control to send legacy commands.
Like during clock-scaling, we may need to send tuning commands
for which we may wait for the device queue to be empty and then halt
the controller to send legacy tuning commands.
Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Signed-off-by: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
[riteshh@xxxxxxxxxxxxxx: fixed merge conflicts]
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
---
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)
--
BR
Ritesh
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