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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>
This commit is contained in:
Boris Brezillon 2014-11-17 14:16:56 +01:00 committed by Michael Turquette
parent ff553ea1a3
commit 69daf75aaf
1 changed files with 15 additions and 14 deletions
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29
drivers/clk/at91/clk-usb.c
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@ -52,29 +52,26 @@ static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
tmp = pmc_read(pmc, AT91_PMC_USB); tmp = pmc_read(pmc, AT91_PMC_USB);
usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT; 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, static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate) unsigned long *parent_rate)
{ {
unsigned long div; unsigned long div;
unsigned long bestrate;
unsigned long tmp; if (!rate)
return -EINVAL;
if (rate >= *parent_rate) if (rate >= *parent_rate)
return *parent_rate; return *parent_rate;
div = *parent_rate / rate; div = DIV_ROUND_CLOSEST(*parent_rate, rate);
if (div >= SAM9X5_USB_MAX_DIV) if (div > SAM9X5_USB_MAX_DIV + 1)
return *parent_rate / (SAM9X5_USB_MAX_DIV + 1); div = SAM9X5_USB_MAX_DIV + 1;
bestrate = *parent_rate / div; return DIV_ROUND_CLOSEST(*parent_rate, div);
tmp = *parent_rate / (div + 1);
if (bestrate - rate > rate - tmp)
bestrate = tmp;
return bestrate;
} }
static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index) 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; u32 tmp;
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw); struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
struct at91_pmc *pmc = usb->pmc; 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; return -EINVAL;
tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV; tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;