[PATCH 12/17] i3c: mipi-i3c-hci: Refactor PIO register initialization

Adrian Hunter
2025-12-19T14:46:18Z

Move the PIO register setup logic out of hci_pio_init() into a new
helper, __hci_pio_init(). This refactoring prepares for Runtime PM
support by allowing PIO registers to be reinitialized independently
after resume.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/i3c/master/mipi-i3c-hci/pio.c | 45 +++++++++++++++++----------
1 file changed, 28 insertions(+), 17 deletions(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c
index 3d633abf6099..52d9f01d9ca9 100644
--- a/drivers/i3c/master/mipi-i3c-hci/pio.c
+++ b/drivers/i3c/master/mipi-i3c-hci/pio.c
@@ -135,27 +135,14 @@ struct hci_pio_data {
u32 enabled_irqs;
};

-static int hci_pio_init(struct i3c_hci *hci)
+static void __hci_pio_init(struct i3c_hci *hci, u32 *size_val_ptr)
{
- struct hci_pio_data *pio;
u32 val, size_val, rx_thresh, tx_thresh, ibi_val;
-
- pio = devm_kzalloc(hci->master.dev.parent, sizeof(*pio), GFP_KERNEL);
- if (!pio)
- return -ENOMEM;
-
- hci->io_data = pio;
- spin_lock_init(&pio->lock);
+ struct hci_pio_data *pio = hci->io_data;

size_val = pio_reg_read(QUEUE_SIZE);
- dev_dbg(&hci->master.dev, "CMD/RESP FIFO = %ld entries\n",
- FIELD_GET(CR_QUEUE_SIZE, size_val));
- dev_dbg(&hci->master.dev, "IBI FIFO = %ld bytes\n",
- 4 * FIELD_GET(IBI_STATUS_SIZE, size_val));
- dev_dbg(&hci->master.dev, "RX data FIFO = %d bytes\n",
- 4 * (2 << FIELD_GET(RX_DATA_BUFFER_SIZE, size_val)));
- dev_dbg(&hci->master.dev, "TX data FIFO = %d bytes\n",
- 4 * (2 << FIELD_GET(TX_DATA_BUFFER_SIZE, size_val)));
+ if (size_val_ptr)
+ *size_val_ptr = size_val;

/*
* Let's initialize data thresholds to half of the actual FIFO size.
@@ -201,6 +188,30 @@ static int hci_pio_init(struct i3c_hci *hci)

/* Always accept error interrupts (will be activated on first xfer) */
pio->enabled_irqs = STAT_ALL_ERRORS;
+}
+
+static int hci_pio_init(struct i3c_hci *hci)
+{
+ struct hci_pio_data *pio;
+ u32 size_val;
+
+ pio = devm_kzalloc(hci->master.dev.parent, sizeof(*pio), GFP_KERNEL);
+ if (!pio)
+ return -ENOMEM;
+
+ hci->io_data = pio;
+ spin_lock_init(&pio->lock);
+
+ __hci_pio_init(hci, &size_val);
+
+ dev_dbg(&hci->master.dev, "CMD/RESP FIFO = %ld entries\n",
+ FIELD_GET(CR_QUEUE_SIZE, size_val));
+ dev_dbg(&hci->master.dev, "IBI FIFO = %ld bytes\n",
+ 4 * FIELD_GET(IBI_STATUS_SIZE, size_val));
+ dev_dbg(&hci->master.dev, "RX data FIFO = %d bytes\n",
+ 4 * (2 << FIELD_GET(RX_DATA_BUFFER_SIZE, size_val)));
+ dev_dbg(&hci->master.dev, "TX data FIFO = %d bytes\n",
+ 4 * (2 << FIELD_GET(TX_DATA_BUFFER_SIZE, size_val)));

return 0;
}
--
2.51.0