usb: uhci: Add clk support to uhci-platform
PATCH v4 1/1 usb: uhci: Add clk support to uhci-platform
Quoted 93 lines · Sergei Shtylyov
Hello!
Quoted 89 lines · Benjamin Herrenschmidt
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 <[email protected]>Acked-by Alan Stern <[email protected]>---
v4. Remove unnecessary NULL checks
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.--- drivers/usb/host/uhci-hcd.h | 3 +++ drivers/usb/host/uhci-platform.c | 20 ++++++++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-)drivers/usb/host/uhci-hcd.h +3
-0@@ -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);drivers/usb/host/uhci-platform.c +15
-2@@ -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); - uhci->regs = hcd->regs;/* Grab some things from the device-tree */ @@ -119,6 +119,19 @@ 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; + } + 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 +140,7 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)return 0 ;
Quoted 5 lines
drivers/usb/host/uhci-platform.c static int uhci_hcd_platform_probe(struct platform_device *pdev) · line 143
Quoted 2 lines
drivers/usb/host/uhci-platform.c +1
-0err_rmr: +clk_disable_unprepare (uhci->clk);Really? You haven't enabled the clock before either *goto* above, why
disable it here?
If clk is NULL or an error, disable will do nothing. The only case would be if enable at failed but then disable will do nothing in that case.
The above change was done at the suggestion of Alan. If you really prefer I could add a clk_put and clearing of "clk" in the error path of clk_prepare_enable, but that's about it.
BTW. DO we really need to bike shed such a simple patch to death like that ?
Quoted 8 lines
drivers/usb/host/uhci-platform.c static int uhci_hcd_platform_probe(struct platform_device *pdev) · line 146
Quoted 4 lines
drivers/usb/host/uhci-platform.c +0
-0usb_put_hcd (hcd);return ret;[...]
MBR, Sergei
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