[PATCH v3 3/3] bus: mhi: host: pci_generic: Add edl callback to enter EDL

[Qiang Yu <quic_qianyu@quicinc.com>]

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@quicinc.com>
---
 drivers/bus/mhi/host/pci_generic.c | 47 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 51639bf..cbf8a58 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -27,12 +27,19 @@
 #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)
+
 /**
  * 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 +51,7 @@ 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 +300,7 @@ 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 +311,7 @@ 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 +322,7 @@ 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 +939,39 @@ 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)
+{
+	void __iomem *base = mhi_cntrl->regs;
+	void __iomem *edl_db;
+	int ret;
+	u32 val;
+
+	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);
+
+	ret = mhi_get_channel_doorbell(mhi_cntrl, &val);
+	if (ret)
+		return ret;
+
+	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 +1006,9 @@ 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;
-- 
2.7.4