[RFC v2 06/11] scsi: ufs: Add support to manage multiple power domains in ufshcd-pltfrm

Rajendra Nayak
2019-03-20T09:50:04Z

Some UFS devices need to manage multiple powerdomains. Add support for
it as part of the ufshcd-pltfrm driver.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
---
drivers/scsi/ufs/ufshcd-pltfrm.c | 52 +++++++++++++++++++++++++++++++-
drivers/scsi/ufs/ufshcd.h | 3 ++
2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 238a79f21e74..ce33eb8b7510 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -34,6 +34,7 @@
*/

#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>

@@ -289,6 +290,43 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
}
}

+static int ufshcd_attach_pds(struct device *dev, struct ufs_hba *hba, int num_pds)
+{
+ int i, ret;
+
+ hba->virt_devs = devm_kzalloc(dev, sizeof(struct device *) * num_pds,
+ GFP_KERNEL);
+ if (!hba->virt_devs)
+ return -ENOMEM;
+
+ hba->num_virt_devs = num_pds;
+ for (i = 0; i < num_pds; i++) {
+ hba->virt_devs[i] = dev_pm_domain_attach_by_id(dev, i);
+ if (IS_ERR(hba->virt_devs[i])) {
+ ret = PTR_ERR(hba->virt_devs[i]);
+ goto unroll_attach;
+ }
+ device_link_add(dev,hba->virt_devs[i], DL_FLAG_RPM_ACTIVE |
+ DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+ }
+
+ return ret;
+
+unroll_attach:
+ for (i--; i >= 0; i--)
+ dev_pm_domain_detach(hba->virt_devs[i], false);
+
+ return ret;
+}
+
+static void ufshcd_detach_pds(struct ufs_hba *hba)
+{
+ int i;
+
+ for (i = 0; i < hba->num_virt_devs; i++)
+ dev_pm_domain_detach(hba->virt_devs[i], false);
+}
+
/**
* ufshcd_pltfrm_init - probe routine of the driver
* @pdev: pointer to Platform device handle
@@ -302,7 +340,7 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
struct ufs_hba *hba;
void __iomem *mmio_base;
struct resource *mem_res;
- int irq, err;
+ int irq, err, num_pds;
struct device *dev = &pdev->dev;

mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -340,6 +378,16 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
goto dealloc_host;
}

+ num_pds = of_count_phandle_with_args(dev->of_node, "power-domains",
+ "#power-domain-cells");
+ if (num_pds > 1) {
+ err = ufshcd_attach_pds(&pdev->dev, hba, num_pds);
+ if (err) {
+ dev_err(&pdev->dev, "%s: attach of power domains failed %d\n",
+ __func__, err);
+ goto dealloc_host;
+ }
+ }
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
@@ -358,6 +406,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
return 0;

out_disable_rpm:
+ if (num_pds > 1)
+ ufshcd_detach_pds(hba);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index ecfa898b9ccc..bca1e008f506 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -517,6 +517,9 @@ struct ufs_hba {

struct Scsi_Host *host;
struct device *dev;
+ struct device **virt_devs;
+ u8 num_virt_devs;
+
/*
* This field is to keep a reference to "scsi_device" corresponding to
* "UFS device" W-LU.