refactor(ufs): add retry logic to ufshc_reset
This change aims to make the UFS code more robust by adding retry logic
and timeouts to ufshc_reset. We also define a new function
ufshc_hce_enable for Host Controller Enable (HCE). The inner and outer
retry pattern is based on Linux's ufshcd_hba_execute_hce function.
Signed-off-by: Jorge Troncoso <jatron@google.com>
Change-Id: I9403a5a25d3ca50af5f2f9a65b774f6a2d7a9626
diff --git a/drivers/ufs/ufs.c b/drivers/ufs/ufs.c
index 97a9d5e..695a614 100644
--- a/drivers/ufs/ufs.c
+++ b/drivers/ufs/ufs.c
@@ -123,21 +123,50 @@
return 0;
}
-static void ufshc_reset(uintptr_t base)
+static int ufshc_hce_enable(uintptr_t base)
{
unsigned int data;
+ int retries;
/* Enable Host Controller */
mmio_write_32(base + HCE, HCE_ENABLE);
+
/* Wait until basic initialization sequence completed */
- do {
+ for (retries = 0; retries < HCE_ENABLE_INNER_RETRIES; ++retries) {
data = mmio_read_32(base + HCE);
- } while ((data & HCE_ENABLE) == 0);
+ if (data & HCE_ENABLE) {
+ break;
+ }
+ udelay(HCE_ENABLE_TIMEOUT_US);
+ }
+ if (retries >= HCE_ENABLE_INNER_RETRIES) {
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int ufshc_reset(uintptr_t base)
+{
+ unsigned int data;
+ int retries, result;
+
+ for (retries = 0; retries < HCE_ENABLE_OUTER_RETRIES; ++retries) {
+ result = ufshc_hce_enable(base);
+ if (result == 0) {
+ break;
+ }
+ }
+ if (retries >= HCE_ENABLE_OUTER_RETRIES) {
+ return -EIO;
+ }
/* Enable Interrupts */
data = UFS_INT_UCCS | UFS_INT_ULSS | UFS_INT_UE | UFS_INT_UTPES |
UFS_INT_DFES | UFS_INT_HCFES | UFS_INT_SBFES;
mmio_write_32(base + IE, data);
+
+ return 0;
}
static int ufshc_link_startup(uintptr_t base)
@@ -782,7 +811,8 @@
assert((ops != NULL) && (ops->phy_init != NULL) &&
(ops->phy_set_pwr_mode != NULL));
- ufshc_reset(ufs_params.reg_base);
+ result = ufshc_reset(ufs_params.reg_base);
+ assert(result == 0);
ops->phy_init(&ufs_params);
result = ufshc_link_startup(ufs_params.reg_base);
assert(result == 0);