@@ -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);
+ div = DIV_ROUND_CLOSEST(*parent_rate, rate);
+ if (div > SAM9X5_USB_MAX_DIV + 1)
+ div = SAM9X5_USB_MAX_DIV + 1;
- bestrate = *parent_rate / div;
- tmp = *parent_rate / (div + 1);
- if (bestrate - rate > rate - tmp)
- bestrate = tmp;
-
- 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 (!rate)
+ return -EINVAL;
- if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV)
+ 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;
This is a note to let you know that I have just added a patch titled clk: at91: usb: fix at91sam9x5 recalc, round and set rate to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt11. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From f16f64f9e4eff1a52a8f455edf191e78849fedd9 Mon Sep 17 00:00:00 2001 From: Boris Brezillon <boris.brezillon@free-electrons.com> Date: Mon, 17 Nov 2014 14:16:56 +0100 Subject: clk: at91: usb: fix at91sam9x5 recalc, round and set rate commit 69daf75aafc8410ef046c70be65c71f2dd4e08f9 upstream. 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> [ luis: 3.16 prereq for: 4591243102fa "clk: at91: usb: propagate rate modification to the parent clk" ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/clk/at91/clk-usb.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-)