From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752532AbbHPJYd (ORCPT ); Sun, 16 Aug 2015 05:24:33 -0400 Received: from down.free-electrons.com ([37.187.137.238]:59677 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751462AbbHPJX4 (ORCPT ); Sun, 16 Aug 2015 05:23:56 -0400 From: Alexandre Belloni To: Nicolas Ferre Cc: Boris Brezillon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandre Belloni , Daniel Lezcano , Thierry Reding , linux-pwm@vger.kernel.org Subject: [PATCH v4 4/4] misc: atmel_tclib: get and use slow clock Date: Sun, 16 Aug 2015 11:23:46 +0200 Message-Id: <1439717026-30634-5-git-send-email-alexandre.belloni@free-electrons.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1439717026-30634-1-git-send-email-alexandre.belloni@free-electrons.com> References: <1439717026-30634-1-git-send-email-alexandre.belloni@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Boris Brezillon Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang") added a workaround for the slow clock as it is not properly handled by its users. Get and use the slow clock as it is necessary for the timer counters. Signed-off-by: Boris Brezillon Signed-off-by: Alexandre Belloni Acked-by: Greg Kroah-Hartman --- Cc: Daniel Lezcano Cc: Thierry Reding Cc: linux-pwm@vger.kernel.org drivers/clocksource/tcb_clksrc.c | 10 +++++++++- drivers/misc/atmel_tclib.c | 4 ++++ drivers/pwm/pwm-atmel-tcb.c | 26 +++++++++++++++++++------- include/linux/atmel_tc.h | 1 + 4 files changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index b9b7277173c2..ba1e5d55d3bf 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -184,10 +184,17 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) struct clk *t2_clk = tc->clk[2]; int irq = tc->irq[2]; + ret = clk_prepare_enable(tc->slow_clk); + if (ret) + return ret; + /* try to enable t2 clk to avoid future errors in mode change */ ret = clk_prepare_enable(t2_clk); - if (ret) + if (ret) { + clk_disable_unprepare(tc->slow_clk); return ret; + } + clk_disable(t2_clk); clkevt.regs = tc->regs; @@ -200,6 +207,7 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx) ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt); if (ret) { clk_unprepare(t2_clk); + clk_disable_unprepare(tc->slow_clk); return ret; } diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c index 0ca05c3ec8d6..ac24a4bd63f7 100644 --- a/drivers/misc/atmel_tclib.c +++ b/drivers/misc/atmel_tclib.c @@ -125,6 +125,10 @@ static int __init tc_probe(struct platform_device *pdev) if (IS_ERR(clk)) return PTR_ERR(clk); + tc->slow_clk = devm_clk_get(&pdev->dev, "slow_clk"); + if (IS_ERR(tc->slow_clk)) + return PTR_ERR(tc->slow_clk); + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); tc->regs = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(tc->regs)) diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c index d14e0677c92d..f64ee392f620 100644 --- a/drivers/pwm/pwm-atmel-tcb.c +++ b/drivers/pwm/pwm-atmel-tcb.c @@ -305,7 +305,7 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, */ if (i == 5) { i = slowclk; - rate = 32768; + rate = clk_get_rate(tc->slow_clk); min = div_u64(NSEC_PER_SEC, rate); max = min << tc->tcb_config->counter_width; @@ -387,9 +387,9 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev) tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL); if (tcbpwm == NULL) { - atmel_tc_free(tc); + err = -ENOMEM; dev_err(&pdev->dev, "failed to allocate memory\n"); - return -ENOMEM; + goto err_free_tc; } tcbpwm->chip.dev = &pdev->dev; @@ -400,17 +400,27 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev) tcbpwm->chip.npwm = NPWM; tcbpwm->tc = tc; + err = clk_prepare_enable(tc->slow_clk); + if (err) + goto err_free_tc; + spin_lock_init(&tcbpwm->lock); err = pwmchip_add(&tcbpwm->chip); - if (err < 0) { - atmel_tc_free(tc); - return err; - } + if (err < 0) + goto err_disable_clk; platform_set_drvdata(pdev, tcbpwm); return 0; + +err_disable_clk: + clk_disable_unprepare(tcbpwm->tc->slow_clk); + +err_free_tc: + atmel_tc_free(tc); + + return err; } static int atmel_tcb_pwm_remove(struct platform_device *pdev) @@ -418,6 +428,8 @@ static int atmel_tcb_pwm_remove(struct platform_device *pdev) struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev); int err; + clk_disable_unprepare(tcbpwm->tc->slow_clk); + err = pwmchip_remove(&tcbpwm->chip); if (err < 0) return err; diff --git a/include/linux/atmel_tc.h b/include/linux/atmel_tc.h index b87c1c7c242a..468fdfa643f0 100644 --- a/include/linux/atmel_tc.h +++ b/include/linux/atmel_tc.h @@ -67,6 +67,7 @@ struct atmel_tc { const struct atmel_tcb_config *tcb_config; int irq[3]; struct clk *clk[3]; + struct clk *slow_clk; struct list_head node; bool allocated; }; -- 2.1.4