From 69daf75aafc8410ef046c70be65c71f2dd4e08f9 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 17 Nov 2014 14:16:56 +0100 Subject: [PATCH] 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 Acked-by: Nicolas Ferre Signed-off-by: Michael Turquette --- drivers/clk/at91/clk-usb.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c index 5b3b63c..a23ac0c 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; -- 2.7.4