Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Guru Das Srinagesh <gurus@codeaurora.org>
To:     linux-pwm@vger.kernel.org
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <uwe@kleine-koenig.org>,
        Subbaraman Narayanamurthy <subbaram@codeaurora.org>,
        linux-kernel@vger.kernel.org,
        Guru Das Srinagesh <gurus@codeaurora.org>,
        Alexander Shiyan <shc_work@mail.ru>
Subject: [PATCH v7 05/13] pwm: clps711x: Use 64-bit division macros for period and duty cycle
Date:   Mon,  9 Mar 2020 12:35:08 -0700
Message-Id: <3c2c8d50bfba2555e3f94c6aa43ae0ac9a0d3d7d.1583782035.git.gurus@codeaurora.org>
In-Reply-To: <cover.1583782035.git.gurus@codeaurora.org>
References: <cover.1583782035.git.gurus@codeaurora.org>
In-Reply-To: <cover.1583782035.git.gurus@codeaurora.org>
References: <cover.1583782035.git.gurus@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Because period and duty cycle are defined in the PWM framework structs
as ints with units of nanoseconds, the maximum time duration that can be
set is limited to ~2.147 seconds. Redefining them as u64 values will
enable larger time durations to be set.

As a first step, prepare drivers to handle the switch to u64 period and
duty_cycle by replacing division operations involving pwm period and duty cycle
with their 64-bit equivalents as appropriate. The actual switch to u64 period
and duty_cycle follows as a separate patch.

Where the dividend is 64-bit but the divisor is 32-bit, use *_ULL
macros:
- DIV_ROUND_UP_ULL
- DIV_ROUND_CLOSEST_ULL
- div_u64

Where the divisor is 64-bit (dividend may be 32-bit or 64-bit), use
DIV64_* macros:
- DIV64_U64_ROUND_CLOSEST
- div64_u64

Cc: Alexander Shiyan <shc_work@mail.ru>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-clps711x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c
index 924d39a..ba9500a 100644
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -43,7 +43,7 @@ static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
 static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
 {
 	/* Duty cycle 0..15 max */
-	return DIV_ROUND_CLOSEST(v * 0xf, pwm->args.period);
+	return DIV64_U64_ROUND_CLOSEST(v * 0xf, pwm->args.period);
 }
 
 static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project