i3c: mipi-i3c-hci: Add a quirk to set PIO mode

The AMD HCI controller currently only supports PIO mode but exposes DMA
rings to the OS, which leads to the controller being configured in DMA
mode. To address this, add a quirk to avoid configuring the controller in
DMA mode and default to PIO mode.

Additionally, introduce a generic quirk infrastructure to the mipi-i3c-hci
driver to facilitate seamless future quirk additions.

Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Guruvendra Punugupati <Guruvendra.Punugupati@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20240829091713.736217-4-Shyam-sundar.S-k@amd.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index a6781cfeebb8468bad0928e5460f3ff30f8194d3..23abf91b277bee44adc9bf00a180634ae758f5d9 100644 (file)
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -756,6 +756,10 @@ static int i3c_hci_init(struct i3c_hci *hci)
        mode_selector = hci->version_major > 1 ||
                                (hci->version_major == 1 && hci->version_minor > 0);
 
+       /* Quirk for HCI_QUIRK_PIO_MODE on AMD platforms */
+       if (hci->quirks & HCI_QUIRK_PIO_MODE)
+               hci->RHS_regs = NULL;
+
        /* Try activating DMA operations first */
        if (hci->RHS_regs) {
                reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
@@ -806,6 +810,8 @@ static int i3c_hci_probe(struct platform_device *pdev)
        /* temporary for dev_printk's, to be replaced in i3c_master_register */
        hci->master.dev.init_name = dev_name(&pdev->dev);
 
+       hci->quirks = (unsigned long)device_get_match_data(&pdev->dev);
+
        ret = i3c_hci_init(hci);
        if (ret)
                return ret;
@@ -838,7 +844,7 @@ static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
 MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
 
 static const struct acpi_device_id i3c_hci_acpi_match[] = {
-       { "AMDI5017" },
+       { "AMDI5017", HCI_QUIRK_PIO_MODE },
        {}
 };
 MODULE_DEVICE_TABLE(acpi, i3c_hci_acpi_match);

diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index f94d95e024becc41106166073fd62edee55d032e..c56b838fb431338b20da0ee8fe5ae68679ed325a 100644 (file)
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -135,6 +135,7 @@ struct i3c_hci_dev_data {
 
 /* list of quirks */
 #define HCI_QUIRK_RAW_CCC      BIT(1)  /* CCC framing must be explicit */
+#define HCI_QUIRK_PIO_MODE     BIT(2)  /* Set PIO mode for AMD platforms */
 
 
 /* global functions */