[PATCH 14/17] i3c: mipi-i3c-hci: Factor out software reset into helper

Adrian Hunter
2025-12-19T14:46:22Z

Prepare for future reuse of the reset sequence in other contexts, such as
power management. Move the software reset logic from i3c_hci_init() into a
dedicated helper function, i3c_hci_software_reset().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/i3c/master/mipi-i3c-hci/core.c | 41 ++++++++++++++++++--------
1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index c4b249fde764..3b0609cb7da7 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -585,6 +585,34 @@ static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
return result;
}

+static int i3c_hci_software_reset(struct i3c_hci *hci)
+{
+ u32 regval;
+ int ret;
+
+ /*
+ * SOFT_RST must be clear before we write to it.
+ * Then we must wait until it clears again.
+ */
+ ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
+ !(regval & SOFT_RST), 0, 10 * USEC_PER_MSEC);
+ if (ret) {
+ dev_err(&hci->master.dev, "%s: Software reset stuck\n", __func__);
+ return ret;
+ }
+
+ reg_write(RESET_CONTROL, SOFT_RST);
+
+ ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
+ !(regval & SOFT_RST), 0, 10 * USEC_PER_MSEC);
+ if (ret) {
+ dev_err(&hci->master.dev, "%s: Software reset failed\n", __func__);
+ return ret;
+ }
+
+ return 0;
+}
+
static int i3c_hci_init(struct i3c_hci *hci)
{
bool size_in_dwords, mode_selector;
@@ -654,18 +682,7 @@ static int i3c_hci_init(struct i3c_hci *hci)
if (ret)
return ret;

- /*
- * Now let's reset the hardware.
- * SOFT_RST must be clear before we write to it.
- * Then we must wait until it clears again.
- */
- ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
- !(regval & SOFT_RST), 1, 10000);
- if (ret)
- return -ENXIO;
- reg_write(RESET_CONTROL, SOFT_RST);
- ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
- !(regval & SOFT_RST), 1, 10000);
+ ret = i3c_hci_software_reset(hci);
if (ret)
return -ENXIO;

--
2.51.0