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mhi: pci_generic: Add support for reset
Add support for resetting the device, reset can be triggered in case of error or manually via sysfs (/sys/bus/pci/devices/*/reset). Signed-off-by: Loic Poulain <loic.poulain@linaro.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
parent
eb96787a5d
commit
8ccc3279fc
1 changed files with 108 additions and 13 deletions
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@ -8,6 +8,7 @@
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* Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
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*/
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/mhi.h>
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#include <linux/module.h>
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@ -15,6 +16,7 @@
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#define MHI_PCI_DEFAULT_BAR_NUM 0
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#define MHI_POST_RESET_DELAY_MS 500
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/**
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* struct mhi_pci_dev_info - MHI PCI device specific information
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* @config: MHI controller configuration
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@ -177,6 +179,16 @@ static const struct pci_device_id mhi_pci_id_table[] = {
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};
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MODULE_DEVICE_TABLE(pci, mhi_pci_id_table);
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enum mhi_pci_device_status {
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MHI_PCI_DEV_STARTED,
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};
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struct mhi_pci_device {
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struct mhi_controller mhi_cntrl;
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struct pci_saved_state *pci_state;
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unsigned long status;
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};
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static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl,
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void __iomem *addr, u32 *out)
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{
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@ -196,6 +208,20 @@ static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl,
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/* Nothing to do for now */
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}
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static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
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{
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struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
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u16 vendor = 0;
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if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
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return false;
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if (vendor == (u16) ~0 || vendor == 0)
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return false;
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return true;
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}
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static int mhi_pci_claim(struct mhi_controller *mhi_cntrl,
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unsigned int bar_num, u64 dma_mask)
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{
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@ -291,16 +317,20 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
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{
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const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *) id->driver_data;
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const struct mhi_controller_config *mhi_cntrl_config;
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struct mhi_pci_device *mhi_pdev;
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struct mhi_controller *mhi_cntrl;
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int err;
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dev_dbg(&pdev->dev, "MHI PCI device found: %s\n", info->name);
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mhi_cntrl = mhi_alloc_controller();
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if (!mhi_cntrl)
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/* mhi_pdev.mhi_cntrl must be zero-initialized */
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mhi_pdev = devm_kzalloc(&pdev->dev, sizeof(*mhi_pdev), GFP_KERNEL);
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if (!mhi_pdev)
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return -ENOMEM;
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mhi_cntrl_config = info->config;
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mhi_cntrl = &mhi_pdev->mhi_cntrl;
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mhi_cntrl->cntrl_dev = &pdev->dev;
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mhi_cntrl->iova_start = 0;
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mhi_cntrl->iova_stop = (dma_addr_t)DMA_BIT_MASK(info->dma_data_width);
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@ -315,17 +345,21 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
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err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width));
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if (err)
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goto err_release;
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return err;
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err = mhi_pci_get_irqs(mhi_cntrl, mhi_cntrl_config);
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if (err)
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goto err_release;
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return err;
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pci_set_drvdata(pdev, mhi_cntrl);
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pci_set_drvdata(pdev, mhi_pdev);
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/* Have stored pci confspace at hand for restore in sudden PCI error */
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pci_save_state(pdev);
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mhi_pdev->pci_state = pci_store_saved_state(pdev);
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err = mhi_register_controller(mhi_cntrl, mhi_cntrl_config);
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if (err)
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goto err_release;
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return err;
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/* MHI bus does not power up the controller by default */
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err = mhi_prepare_for_power_up(mhi_cntrl);
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@ -340,33 +374,94 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
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goto err_unprepare;
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}
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set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
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return 0;
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err_unprepare:
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mhi_unprepare_after_power_down(mhi_cntrl);
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err_unregister:
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mhi_unregister_controller(mhi_cntrl);
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err_release:
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mhi_free_controller(mhi_cntrl);
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return err;
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}
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static void mhi_pci_remove(struct pci_dev *pdev)
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{
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struct mhi_controller *mhi_cntrl = pci_get_drvdata(pdev);
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struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
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struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
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if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
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mhi_power_down(mhi_cntrl, true);
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mhi_unprepare_after_power_down(mhi_cntrl);
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}
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mhi_power_down(mhi_cntrl, true);
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mhi_unprepare_after_power_down(mhi_cntrl);
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mhi_unregister_controller(mhi_cntrl);
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mhi_free_controller(mhi_cntrl);
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}
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static void mhi_pci_reset_prepare(struct pci_dev *pdev)
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{
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struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
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struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
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dev_info(&pdev->dev, "reset\n");
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/* Clean up MHI state */
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if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
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mhi_power_down(mhi_cntrl, false);
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mhi_unprepare_after_power_down(mhi_cntrl);
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}
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/* cause internal device reset */
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mhi_soc_reset(mhi_cntrl);
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/* Be sure device reset has been executed */
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msleep(MHI_POST_RESET_DELAY_MS);
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}
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static void mhi_pci_reset_done(struct pci_dev *pdev)
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{
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struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
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struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
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int err;
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/* Restore initial known working PCI state */
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pci_load_saved_state(pdev, mhi_pdev->pci_state);
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pci_restore_state(pdev);
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/* Is device status available ? */
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if (!mhi_pci_is_alive(mhi_cntrl)) {
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dev_err(&pdev->dev, "reset failed\n");
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return;
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}
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err = mhi_prepare_for_power_up(mhi_cntrl);
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if (err) {
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dev_err(&pdev->dev, "failed to prepare MHI controller\n");
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return;
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}
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err = mhi_sync_power_up(mhi_cntrl);
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if (err) {
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dev_err(&pdev->dev, "failed to power up MHI controller\n");
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mhi_unprepare_after_power_down(mhi_cntrl);
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return;
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}
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set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
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}
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static const struct pci_error_handlers mhi_pci_err_handler = {
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.reset_prepare = mhi_pci_reset_prepare,
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.reset_done = mhi_pci_reset_done,
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};
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static struct pci_driver mhi_pci_driver = {
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.name = "mhi-pci-generic",
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.id_table = mhi_pci_id_table,
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.probe = mhi_pci_probe,
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.remove = mhi_pci_remove
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.remove = mhi_pci_remove,
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.err_handler = &mhi_pci_err_handler,
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};
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module_pci_driver(mhi_pci_driver);
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