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authorBoris Brezillon <boris.brezillon@free-electrons.com>2014-11-17 16:16:56 +0300
committerMichael Turquette <mturquette@linaro.org>2014-11-17 21:38:40 +0300
commit69daf75aafc8410ef046c70be65c71f2dd4e08f9 (patch)
treebe9397ee4a44717bcd8648816ddeff31284ef83c /drivers/clk/at91/clk-usb.c
parentff553ea1a3d5b903becda790eeb6bd3debf239f9 (diff)
downloadlinux-69daf75aafc8410ef046c70be65c71f2dd4e08f9.tar.xz
clk: at91: usb: fix at91sam9x5 recalc, round and set rate
First check for rate == 0 in set_rate and round_rate to avoid div by zero. Then, in order to get the closest rate, round all divisions to the closest result instead of rounding them down. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/at91/clk-usb.c')
-rw-r--r--drivers/clk/at91/clk-usb.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c
index 5b3b63c07524..a23ac0c724f0 100644
--- a/drivers/clk/at91/clk-usb.c
+++ b/drivers/clk/at91/clk-usb.c
@@ -52,29 +52,26 @@ static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
tmp = pmc_read(pmc, AT91_PMC_USB);
usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
- return parent_rate / (usbdiv + 1);
+
+ return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
}
static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned long div;
- unsigned long bestrate;
- unsigned long tmp;
+
+ if (!rate)
+ return -EINVAL;
if (rate >= *parent_rate)
return *parent_rate;
- div = *parent_rate / rate;
- if (div >= SAM9X5_USB_MAX_DIV)
- return *parent_rate / (SAM9X5_USB_MAX_DIV + 1);
-
- bestrate = *parent_rate / div;
- tmp = *parent_rate / (div + 1);
- if (bestrate - rate > rate - tmp)
- bestrate = tmp;
+ div = DIV_ROUND_CLOSEST(*parent_rate, rate);
+ if (div > SAM9X5_USB_MAX_DIV + 1)
+ div = SAM9X5_USB_MAX_DIV + 1;
- return bestrate;
+ return DIV_ROUND_CLOSEST(*parent_rate, div);
}
static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
@@ -106,9 +103,13 @@ static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
u32 tmp;
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc;
- unsigned long div = parent_rate / rate;
+ unsigned long div;
- if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV)
+ if (!rate)
+ return -EINVAL;
+
+ div = DIV_ROUND_CLOSEST(parent_rate, rate);
+ if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
return -EINVAL;
tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;