linux/drivers/scsi/ufs/ufshcd-pci.c
Subhash Jadavani 57d104c153 ufs: add UFS power management support
This patch adds support for UFS device and UniPro link power management
during runtime/system PM.

Main idea is to define multiple UFS low power levels based on UFS device
and UFS link power states. This would allow any specific platform or pci
driver to choose the best suited low power level during runtime and
system suspend based on their power goals.

bkops handlig:
To put the UFS device in sleep state when bkops is disabled, first query
the bkops status from the device and enable bkops on device only if
device needs time to perform the bkops.

START_STOP handling:
Before sending START_STOP_UNIT to the device well-known logical unit
(w-lun) to make sure that the device w-lun unit attention condition is
cleared.

Write protection:
UFS device specification allows LUs to be write protected, either
permanently or power on write protected. If any LU is power on write
protected and if the card is power cycled (by powering off VCCQ and/or
VCC rails), LU's write protect status would be lost. So this means those
LUs can be written now. To ensures that UFS device is power cycled only
if the power on protect is not set for any of the LUs, check if power on
write protect is set and if device is in sleep/power-off state & link in
inactive state (Hibern8 or OFF state).
If none of the Logical Units on UFS device is power on write protected
then all UFS device power rails (VCC, VCCQ & VCCQ2) can be turned off if
UFS device is in power-off state and UFS link is in OFF state. But current
implementation would disable all device power rails even if UFS link is
not in OFF state.

Low power mode:
If UFS link is in OFF state then UFS host controller can be power collapsed
to avoid leakage current from it. Note that if UFS host controller is power
collapsed, full UFS reinitialization will be required on resume to
re-establish the link between host and device.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-10-01 13:11:23 +02:00

196 lines
5.3 KiB
C

/*
* Universal Flash Storage Host controller PCI glue driver
*
* This code is based on drivers/scsi/ufs/ufshcd-pci.c
* Copyright (C) 2011-2013 Samsung India Software Operations
*
* Authors:
* Santosh Yaraganavi <santosh.sy@samsung.com>
* Vinayak Holikatti <h.vinayak@samsung.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* See the COPYING file in the top-level directory or visit
* <http://www.gnu.org/licenses/gpl-2.0.html>
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* This program is provided "AS IS" and "WITH ALL FAULTS" and
* without warranty of any kind. You are solely responsible for
* determining the appropriateness of using and distributing
* the program and assume all risks associated with your exercise
* of rights with respect to the program, including but not limited
* to infringement of third party rights, the risks and costs of
* program errors, damage to or loss of data, programs or equipment,
* and unavailability or interruption of operations. Under no
* circumstances will the contributor of this Program be liable for
* any damages of any kind arising from your use or distribution of
* this program.
*/
#include "ufshcd.h"
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#ifdef CONFIG_PM
/**
* ufshcd_pci_suspend - suspend power management function
* @pdev: pointer to PCI device handle
* @state: power state
*
* Returns 0 if successful
* Returns non-zero otherwise
*/
static int ufshcd_pci_suspend(struct device *dev)
{
return ufshcd_system_suspend(dev_get_drvdata(dev));
}
/**
* ufshcd_pci_resume - resume power management function
* @pdev: pointer to PCI device handle
*
* Returns 0 if successful
* Returns non-zero otherwise
*/
static int ufshcd_pci_resume(struct device *dev)
{
return ufshcd_system_resume(dev_get_drvdata(dev));
}
#else
#define ufshcd_pci_suspend NULL
#define ufshcd_pci_resume NULL
#endif /* CONFIG_PM */
#ifdef CONFIG_PM_RUNTIME
static int ufshcd_pci_runtime_suspend(struct device *dev)
{
return ufshcd_runtime_suspend(dev_get_drvdata(dev));
}
static int ufshcd_pci_runtime_resume(struct device *dev)
{
return ufshcd_runtime_resume(dev_get_drvdata(dev));
}
static int ufshcd_pci_runtime_idle(struct device *dev)
{
return ufshcd_runtime_idle(dev_get_drvdata(dev));
}
#else /* !CONFIG_PM_RUNTIME */
#define ufshcd_pci_runtime_suspend NULL
#define ufshcd_pci_runtime_resume NULL
#define ufshcd_pci_runtime_idle NULL
#endif /* CONFIG_PM_RUNTIME */
/**
* ufshcd_pci_shutdown - main function to put the controller in reset state
* @pdev: pointer to PCI device handle
*/
static void ufshcd_pci_shutdown(struct pci_dev *pdev)
{
ufshcd_shutdown((struct ufs_hba *)pci_get_drvdata(pdev));
}
/**
* ufshcd_pci_remove - de-allocate PCI/SCSI host and host memory space
* data structure memory
* @pdev - pointer to PCI handle
*/
static void ufshcd_pci_remove(struct pci_dev *pdev)
{
struct ufs_hba *hba = pci_get_drvdata(pdev);
pm_runtime_forbid(&pdev->dev);
pm_runtime_get_noresume(&pdev->dev);
ufshcd_remove(hba);
}
/**
* ufshcd_pci_probe - probe routine of the driver
* @pdev: pointer to PCI device handle
* @id: PCI device id
*
* Returns 0 on success, non-zero value on failure
*/
static int
ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct ufs_hba *hba;
void __iomem *mmio_base;
int err;
err = pcim_enable_device(pdev);
if (err) {
dev_err(&pdev->dev, "pcim_enable_device failed\n");
return err;
}
pci_set_master(pdev);
err = pcim_iomap_regions(pdev, 1 << 0, UFSHCD);
if (err < 0) {
dev_err(&pdev->dev, "request and iomap failed\n");
return err;
}
mmio_base = pcim_iomap_table(pdev)[0];
err = ufshcd_alloc_host(&pdev->dev, &hba);
if (err) {
dev_err(&pdev->dev, "Allocation failed\n");
return err;
}
INIT_LIST_HEAD(&hba->clk_list_head);
err = ufshcd_init(hba, mmio_base, pdev->irq);
if (err) {
dev_err(&pdev->dev, "Initialization failed\n");
return err;
}
pci_set_drvdata(pdev, hba);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_allow(&pdev->dev);
return 0;
}
static const struct dev_pm_ops ufshcd_pci_pm_ops = {
.suspend = ufshcd_pci_suspend,
.resume = ufshcd_pci_resume,
.runtime_suspend = ufshcd_pci_runtime_suspend,
.runtime_resume = ufshcd_pci_runtime_resume,
.runtime_idle = ufshcd_pci_runtime_idle,
};
static const struct pci_device_id ufshcd_pci_tbl[] = {
{ PCI_VENDOR_ID_SAMSUNG, 0xC00C, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
{ } /* terminate list */
};
MODULE_DEVICE_TABLE(pci, ufshcd_pci_tbl);
static struct pci_driver ufshcd_pci_driver = {
.name = UFSHCD,
.id_table = ufshcd_pci_tbl,
.probe = ufshcd_pci_probe,
.remove = ufshcd_pci_remove,
.shutdown = ufshcd_pci_shutdown,
.driver = {
.pm = &ufshcd_pci_pm_ops
},
};
module_pci_driver(ufshcd_pci_driver);
MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
MODULE_DESCRIPTION("UFS host controller PCI glue driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(UFSHCD_DRIVER_VERSION);