From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/drivers/pwm/pwm-bcm2835.c | 28 ++++++++++++----------------
1 files changed, 12 insertions(+), 16 deletions(-)
diff --git a/kernel/drivers/pwm/pwm-bcm2835.c b/kernel/drivers/pwm/pwm-bcm2835.c
index e340ad7..6841dcf 100644
--- a/kernel/drivers/pwm/pwm-bcm2835.c
+++ b/kernel/drivers/pwm/pwm-bcm2835.c
@@ -1,9 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2014 Bart Tanghe <bart.tanghe@thomasmore.be>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2.
*/
#include <linux/clk.h>
@@ -24,7 +21,7 @@
#define PERIOD(x) (((x) * 0x10) + 0x10)
#define DUTY(x) (((x) * 0x10) + 0x14)
-#define MIN_PERIOD 108 /* 9.2 MHz max. PWM clock */
+#define PERIOD_MIN 0x2
struct bcm2835_pwm {
struct pwm_chip chip;
@@ -67,22 +64,22 @@
struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
unsigned long rate = clk_get_rate(pc->clk);
unsigned long scaler;
+ u32 period;
if (!rate) {
dev_err(pc->dev, "failed to get clock rate\n");
return -EINVAL;
}
- scaler = NSEC_PER_SEC / rate;
+ scaler = DIV_ROUND_CLOSEST(NSEC_PER_SEC, rate);
+ period = DIV_ROUND_CLOSEST(period_ns, scaler);
- if (period_ns <= MIN_PERIOD) {
- dev_err(pc->dev, "period %d not supported, minimum %d\n",
- period_ns, MIN_PERIOD);
+ if (period < PERIOD_MIN)
return -EINVAL;
- }
- writel(duty_ns / scaler, pc->base + DUTY(pwm->hwpwm));
- writel(period_ns / scaler, pc->base + PERIOD(pwm->hwpwm));
+ writel(DIV_ROUND_CLOSEST(duty_ns, scaler),
+ pc->base + DUTY(pwm->hwpwm));
+ writel(period, pc->base + PERIOD(pwm->hwpwm));
return 0;
}
@@ -155,10 +152,9 @@
return PTR_ERR(pc->base);
pc->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(pc->clk)) {
- dev_err(&pdev->dev, "clock not found: %ld\n", PTR_ERR(pc->clk));
- return PTR_ERR(pc->clk);
- }
+ if (IS_ERR(pc->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
+ "clock not found\n");
ret = clk_prepare_enable(pc->clk);
if (ret)
--
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