From: Guru Das Srinagesh <gurus@codeaurora.org>
Date: Tue, 2 Jun 2020 22:31:15 +0000 (-0700)
Subject: clk: pwm: Use 64-bit division function
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a6733474ba4bf3150120bacc1d2db446d89d3dbe;p=linux.git

clk: pwm: Use 64-bit division function

Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using div64_u64() to handle a
64-bit divisor.

Also ensure that divide-by-zero (with fixed_rate as denominator) does
not happen with an explicit check with probe failure as a consequence.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
---

diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
index 87fe0b0e01a3d..86f2e2d3fc022 100644
--- a/drivers/clk/clk-pwm.c
+++ b/drivers/clk/clk-pwm.c
@@ -89,7 +89,12 @@ static int clk_pwm_probe(struct platform_device *pdev)
 	}
 
 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
-		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
+		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
+
+	if (!clk_pwm->fixed_rate) {
+		dev_err(&pdev->dev, "fixed_rate cannot be zero\n");
+		return -EINVAL;
+	}
 
 	if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
 	    pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {