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authorBoris Brezillon <boris.brezillon@free-electrons.com>2015-03-17 12:15:46 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-18 08:28:35 -0400
commite32643a7443e2a601f86cb1be4a0c080949e007f (patch)
treedf3e99bf3b22531dcf933617c38deea53bcdad26 /drivers/usb
parent963ffa3e97d4011cbc545d4236179f227e199f3f (diff)
USB: ehci-atmel: rework clk handling
The EHCI IP only needs the UTMI/UPLL (uclk) and the peripheral (iclk) clocks to work properly. Remove the useless system clock (fclk). Avoid calling set_rate on the fixed rate UTMI/IPLL clock and remove useless IS_ENABLED(CONFIG_COMMON_CLK) tests (all at91 platforms have been moved to the CCF). This patch also fixes a bug introduced by 3440ef1 (ARM: at91/dt: fix USB high-speed clock to select UTMI), which was leaving the usb clock uninitialized and preventing the OHCI driver from setting the usb clock rate to 48MHz. This bug was caused by several things: 1/ usb clock drivers set the CLK_SET_RATE_GATE flag, which means the rate cannot be changed once the clock is prepared 2/ The EHCI driver was retrieving and preparing/enabling the uhpck clock which was in turn preparing its parent clock (the usb clock), thus preventing any rate change because of 1/ Fixes: 3440ef169100 ("ARM: at91/dt: fix USB high-speed clock to select UTMI") Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/ehci-atmel.c30
1 files changed, 9 insertions, 21 deletions
diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 663f7908b15c..be0964a801e8 100644
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -34,7 +34,6 @@ static const char hcd_name[] = "ehci-atmel";
34 34
35struct atmel_ehci_priv { 35struct atmel_ehci_priv {
36 struct clk *iclk; 36 struct clk *iclk;
37 struct clk *fclk;
38 struct clk *uclk; 37 struct clk *uclk;
39 bool clocked; 38 bool clocked;
40}; 39};
@@ -51,12 +50,9 @@ static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci)
51{ 50{
52 if (atmel_ehci->clocked) 51 if (atmel_ehci->clocked)
53 return; 52 return;
54 if (IS_ENABLED(CONFIG_COMMON_CLK)) { 53
55 clk_set_rate(atmel_ehci->uclk, 48000000); 54 clk_prepare_enable(atmel_ehci->uclk);
56 clk_prepare_enable(atmel_ehci->uclk);
57 }
58 clk_prepare_enable(atmel_ehci->iclk); 55 clk_prepare_enable(atmel_ehci->iclk);
59 clk_prepare_enable(atmel_ehci->fclk);
60 atmel_ehci->clocked = true; 56 atmel_ehci->clocked = true;
61} 57}
62 58
@@ -64,10 +60,9 @@ static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci)
64{ 60{
65 if (!atmel_ehci->clocked) 61 if (!atmel_ehci->clocked)
66 return; 62 return;
67 clk_disable_unprepare(atmel_ehci->fclk); 63
68 clk_disable_unprepare(atmel_ehci->iclk); 64 clk_disable_unprepare(atmel_ehci->iclk);
69 if (IS_ENABLED(CONFIG_COMMON_CLK)) 65 clk_disable_unprepare(atmel_ehci->uclk);
70 clk_disable_unprepare(atmel_ehci->uclk);
71 atmel_ehci->clocked = false; 66 atmel_ehci->clocked = false;
72} 67}
73 68
@@ -146,20 +141,13 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
146 retval = -ENOENT; 141 retval = -ENOENT;
147 goto fail_request_resource; 142 goto fail_request_resource;
148 } 143 }
149 atmel_ehci->fclk = devm_clk_get(&pdev->dev, "uhpck"); 144
150 if (IS_ERR(atmel_ehci->fclk)) { 145 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
151 dev_err(&pdev->dev, "Error getting function clock\n"); 146 if (IS_ERR(atmel_ehci->uclk)) {
152 retval = -ENOENT; 147 dev_err(&pdev->dev, "failed to get uclk\n");
148 retval = PTR_ERR(atmel_ehci->uclk);
153 goto fail_request_resource; 149 goto fail_request_resource;
154 } 150 }
155 if (IS_ENABLED(CONFIG_COMMON_CLK)) {
156 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk");
157 if (IS_ERR(atmel_ehci->uclk)) {
158 dev_err(&pdev->dev, "failed to get uclk\n");
159 retval = PTR_ERR(atmel_ehci->uclk);
160 goto fail_request_resource;
161 }
162 }
163 151
164 ehci = hcd_to_ehci(hcd); 152 ehci = hcd_to_ehci(hcd);
165 /* registers start at offset 0x0 */ 153 /* registers start at offset 0x0 */