diff options
| author | Boris Brezillon <boris.brezillon@free-electrons.com> | 2014-11-17 14:16:56 +0100 |
|---|---|---|
| committer | Michael Turquette <mturquette@linaro.org> | 2014-11-17 10:38:40 -0800 |
| commit | 69daf75aafc8410ef046c70be65c71f2dd4e08f9 (patch) | |
| tree | be9397ee4a44717bcd8648816ddeff31284ef83c /drivers/clk/at91 | |
| parent | ff553ea1a3d5b903becda790eeb6bd3debf239f9 (diff) | |
| download | linux-69daf75aafc8410ef046c70be65c71f2dd4e08f9.tar.bz2 | |
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')
| -rw-r--r-- | drivers/clk/at91/clk-usb.c | 29 |
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; |