[v3] usb: uhci: Add clk support to uhci-platform
From: Alan Stern <stern@rowland.harvard.edu>
Date: 2018-01-13 03:35:28
On Sat, 13 Jan 2018, Benjamin Herrenschmidt wrote:
The Aspeed SoCs use uhci-platform. With the new dynamic clock
control framework, the corresponding IP block clock must be
properly enabled.
This is a simplified variant of what ehci-platform does, it
looks for *one* clock attached to the device, and if it's
there, enables it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
v3. Fix tab vs. spaces and probe error path
v2. Don't forget to git add latest changes :-) This adds the
part where we turn the clock off when removing the driver.quoted hunk
drivers/usb/host/uhci-hcd.h | 3 +++ drivers/usb/host/uhci-platform.c | 24 ++++++++++++++++++++++-- 2 files changed, 25 insertions(+), 2 deletions(-)diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h index f1cc47292a59..7f9f33c8c232 100644 --- a/drivers/usb/host/uhci-hcd.h +++ b/drivers/usb/host/uhci-hcd.h@@ -4,6 +4,7 @@ #include <linux/list.h> #include <linux/usb.h> +#include <linux/clk.h> #define usb_packetid(pipe) (usb_pipein(pipe) ? USB_PID_IN : USB_PID_OUT) #define PIPE_DEVEP_MASK 0x0007ff00@@ -447,6 +448,8 @@ struct uhci_hcd { int total_load; /* Sum of array values */ short load[MAX_PHASE]; /* Periodic allocations */ + struct clk *clk; /* (optional) clock source */ + /* Reset host controller */ void (*reset_hc) (struct uhci_hcd *uhci); int (*check_and_reset_hc) (struct uhci_hcd *uhci);diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c index 6cb16d4b2257..0d86ad244922 100644 --- a/drivers/usb/host/uhci-platform.c +++ b/drivers/usb/host/uhci-platform.c@@ -89,6 +89,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev) if (!hcd) return -ENOMEM; + uhci = hcd_to_uhci(hcd); + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); hcd->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(hcd->regs)) {@@ -98,8 +100,6 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev) hcd->rsrc_start = res->start; hcd->rsrc_len = resource_size(res); - uhci = hcd_to_uhci(hcd); -
Any particular reason for moving this line up?
quoted hunk
uhci->regs = hcd->regs; /* Grab some things from the device-tree */@@ -119,6 +119,21 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev) "Enabled Aspeed implementation workarounds\n"); } } + + /* Get and enable clock if any specified */ + uhci->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(uhci->clk)) { + ret = PTR_ERR(uhci->clk); + goto err_rmr; + } + if (uhci->clk) { + ret = clk_prepare_enable(uhci->clk); + if (ret) { + dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", ret); + goto err_rmr; + } + } + ret = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED); if (ret) goto err_rmr;@@ -127,6 +142,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev) return 0; err_rmr: + if (uhci->clk) + clk_disable_unprepare(uhci->clk);
You don't actually need the test here or below. Both clk_disable and clk_unprepare test for IS_ERR_OR_NULL. Anyway, this all looks okay. If you want to submit a v4, you can add Acked-by: Alan Stern <stern@rowland.harvard.edu> Alan Stern
quoted hunk
usb_put_hcd(hcd); return ret;@@ -135,7 +152,10 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev) static int uhci_hcd_platform_remove(struct platform_device *pdev) { struct usb_hcd *hcd = platform_get_drvdata(pdev); + struct uhci_hcd *uhci = hcd_to_uhci(hcd); + if (uhci->clk) + clk_disable_unprepare(uhci->clk); usb_remove_hcd(hcd); usb_put_hcd(hcd);
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