Re: [PATCH v2 2/2] bus: mhi: host: pci_generic: Add edl callback to enter EDL

From: Qiang Yu
Date: Mon Apr 15 2024 - 01:49:26 EST



On 4/13/2024 1:09 AM, Manivannan Sadhasivam wrote:
On Fri, Apr 12, 2024 at 08:16:52AM -0600, Jeffrey Hugo wrote:
On 4/12/2024 1:13 AM, Qiang Yu wrote:
On 4/11/2024 10:46 PM, Jeffrey Hugo wrote:
On 4/10/2024 9:15 PM, Qiang Yu wrote:
Add mhi_pci_generic_edl_trigger as edl_trigger for some devices
(eg. SDX65)
to enter EDL mode by writing the 0xEDEDEDED cookie to the channel 91
doorbell register and forcing an SOC reset afterwards.

Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
---
  drivers/bus/mhi/host/pci_generic.c | 50
++++++++++++++++++++++++++++++++++++++
  1 file changed, 50 insertions(+)

diff --git a/drivers/bus/mhi/host/pci_generic.c
b/drivers/bus/mhi/host/pci_generic.c
index 51639bf..a529815 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -27,12 +27,23 @@
  #define PCI_VENDOR_ID_THALES    0x1269
  #define PCI_VENDOR_ID_QUECTEL    0x1eac
  +#define MHI_EDL_DB            91
+#define MHI_EDL_COOKIE            0xEDEDEDED
+
+/* Device can enter EDL by first setting edl cookie then
issuing inband reset*/
+#define MHI_PCI_GENERIC_EDL_TRIGGER    BIT(0)
+
+#define CHDBOFF            0x18
This is already in drivers/bus/mhi/common.h why duplicate it here?
I only see common.h be included in ep/internal.h host/internal.h and
host/trace.h. So I thought it can only be used by MHI stack. Can we
include common.h in pci_generic.c?
Up to Mani, but duplicating the definition seems like it would result in
maintence overhead over time. An alternative to including the header might
be a new API between MHI and controller which allow the setting of a CHDB to
a specific value.

+1 to the new API suggestion.

- Mani

OK, will add a new API in MHI to allow controller get CHDB address.
+#define CHDBOFF_CHDBOFF_MASK 0xFFFFFFFF
+#define CHDBOFF_CHDBOFF_SHIFT    0
+
  /**
   * struct mhi_pci_dev_info - MHI PCI device specific information
   * @config: MHI controller configuration
   * @name: name of the PCI module
   * @fw: firmware path (if any)
   * @edl: emergency download mode firmware path (if any)
+ * @edl_trigger: each bit represents a different way to enter EDL
   * @bar_num: PCI base address register to use for MHI MMIO
register space
   * @dma_data_width: DMA transfer word size (32 or 64 bits)
   * @mru_default: default MRU size for MBIM network packets
@@ -44,6 +55,7 @@ struct mhi_pci_dev_info {
      const char *name;
      const char *fw;
      const char *edl;
+    unsigned int edl_trigger;
      unsigned int bar_num;
      unsigned int dma_data_width;
      unsigned int mru_default;
@@ -292,6 +304,7 @@ static const struct mhi_pci_dev_info
mhi_qcom_sdx75_info = {
      .name = "qcom-sdx75m",
      .fw = "qcom/sdx75m/xbl.elf",
      .edl = "qcom/sdx75m/edl.mbn",
+    .edl_trigger = MHI_PCI_GENERIC_EDL_TRIGGER,
      .config = &modem_qcom_v2_mhiv_config,
      .bar_num = MHI_PCI_DEFAULT_BAR_NUM,
      .dma_data_width = 32,
@@ -302,6 +315,7 @@ static const struct mhi_pci_dev_info
mhi_qcom_sdx65_info = {
      .name = "qcom-sdx65m",
      .fw = "qcom/sdx65m/xbl.elf",
      .edl = "qcom/sdx65m/edl.mbn",
+    .edl_trigger = MHI_PCI_GENERIC_EDL_TRIGGER,
      .config = &modem_qcom_v1_mhiv_config,
      .bar_num = MHI_PCI_DEFAULT_BAR_NUM,
      .dma_data_width = 32,
@@ -312,6 +326,7 @@ static const struct mhi_pci_dev_info
mhi_qcom_sdx55_info = {
      .name = "qcom-sdx55m",
      .fw = "qcom/sdx55m/sbl1.mbn",
      .edl = "qcom/sdx55m/edl.mbn",
+    .edl_trigger = MHI_PCI_GENERIC_EDL_TRIGGER,
      .config = &modem_qcom_v1_mhiv_config,
      .bar_num = MHI_PCI_DEFAULT_BAR_NUM,
      .dma_data_width = 32,
@@ -928,6 +943,38 @@ static void health_check(struct timer_list *t)
      mod_timer(&mhi_pdev->health_check_timer, jiffies +
HEALTH_CHECK_PERIOD);
  }
  +static int mhi_pci_generic_edl_trigger(struct mhi_controller
*mhi_cntrl)
+{
+    int ret;
+    u32 val;
+    void __iomem *edl_db;
+    void __iomem *base = mhi_cntrl->regs;
It looks like this file follows reverse christmas tree, but this
function does not. you should fix it.
Will fix it in next version patch.
+
+    ret = mhi_device_get_sync(mhi_cntrl->mhi_dev);
+    if (ret) {
+        dev_err(mhi_cntrl->cntrl_dev, "Wake up device fail
before trigger EDL\n");
+        return ret;
+    }
+
+    pm_wakeup_event(&mhi_cntrl->mhi_dev->dev, 0);
+    mhi_cntrl->runtime_get(mhi_cntrl);
+
+    mhi_cntrl->read_reg(mhi_cntrl, base + CHDBOFF, &val);
+    val = (val & CHDBOFF_CHDBOFF_MASK) >> CHDBOFF_CHDBOFF_SHIFT;
+
+    edl_db = base + val + (8 * MHI_EDL_DB);
+
+    mhi_cntrl->write_reg(mhi_cntrl, edl_db + 4,
upper_32_bits(MHI_EDL_COOKIE));
+    mhi_cntrl->write_reg(mhi_cntrl, edl_db,
lower_32_bits(MHI_EDL_COOKIE));
+
+    mhi_soc_reset(mhi_cntrl);
+
+    mhi_cntrl->runtime_put(mhi_cntrl);
+    mhi_device_put(mhi_cntrl->mhi_dev);
+
+    return 0;
+}
+
  static int mhi_pci_probe(struct pci_dev *pdev, const struct
pci_device_id *id)
  {
      const struct mhi_pci_dev_info *info = (struct
mhi_pci_dev_info *) id->driver_data;
@@ -962,6 +1009,9 @@ static int mhi_pci_probe(struct pci_dev
*pdev, const struct pci_device_id *id)
      mhi_cntrl->runtime_put = mhi_pci_runtime_put;
      mhi_cntrl->mru = info->mru_default;
  +    if (info->edl_trigger & MHI_PCI_GENERIC_EDL_TRIGGER)
+        mhi_cntrl->edl_trigger = mhi_pci_generic_edl_trigger;
+
      if (info->sideband_wake) {
          mhi_cntrl->wake_get = mhi_pci_wake_get_nop;
          mhi_cntrl->wake_put = mhi_pci_wake_put_nop;