Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932600AbcDSPe7 (ORCPT ); Tue, 19 Apr 2016 11:34:59 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:55199 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932531AbcDSPe6 (ORCPT ); Tue, 19 Apr 2016 11:34:58 -0400 Subject: Re: [PATCH] pwms: pwm-ti*: Remove support for local clock gating To: , , , , , , , References: <1457379236-14797-1-git-send-email-fcooper@ti.com> From: "Franklin S Cooper Jr." Message-ID: <5716501B.7010901@ti.com> Date: Tue, 19 Apr 2016 10:34:51 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1457379236-14797-1-git-send-email-fcooper@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8957 Lines: 292 On 03/07/2016 01:33 PM, Franklin S Cooper Jr wrote: > The PWMSS local clock gating registers have no real purpose on OMAP ARM > devices. These registers were left over registers from DSP IP where the > PRCM doesn't exist. There is a silicon bug where gating and ungating clocks > don't function properly. TRMs will be update to indicate that these > registers shouldn't be touched. > > Therefore, all code that accesses the PWMSS_CLKCONFIG or PWMSS_CLKSTATUS > will be removed by this patch with zero loss of functionality by the ECAP > and EPWM drivers. > > Signed-off-by: Franklin S Cooper Jr > --- > Tested on: AM335x and AM437x GP evms. > > drivers/pwm/pwm-tiecap.c | 28 -------------------------- > drivers/pwm/pwm-tiehrpwm.c | 29 --------------------------- > drivers/pwm/pwm-tipwmss.c | 49 ---------------------------------------------- > drivers/pwm/pwm-tipwmss.h | 39 ------------------------------------ > 4 files changed, 145 deletions(-) > delete mode 100644 drivers/pwm/pwm-tipwmss.h > > diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c > index 616af76..9e0865d7 100644 > --- a/drivers/pwm/pwm-tiecap.c > +++ b/drivers/pwm/pwm-tiecap.c > @@ -27,8 +27,6 @@ > #include > #include > > -#include "pwm-tipwmss.h" > - > /* ECAP registers and bits definitions */ > #define CAP1 0x08 > #define CAP2 0x0C > @@ -206,7 +204,6 @@ static int ecap_pwm_probe(struct platform_device *pdev) > struct resource *r; > struct clk *clk; > struct ecap_pwm_chip *pc; > - u16 status; > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > if (!pc) > @@ -243,40 +240,15 @@ static int ecap_pwm_probe(struct platform_device *pdev) > } > > pm_runtime_enable(&pdev->dev); > - pm_runtime_get_sync(&pdev->dev); > - > - status = pwmss_submodule_state_change(pdev->dev.parent, > - PWMSS_ECAPCLK_EN); > - if (!(status & PWMSS_ECAPCLK_EN_ACK)) { > - dev_err(&pdev->dev, "PWMSS config space clock enable failed\n"); > - ret = -EINVAL; > - goto pwmss_clk_failure; > - } > - > - pm_runtime_put_sync(&pdev->dev); > > platform_set_drvdata(pdev, pc); > return 0; > - > -pwmss_clk_failure: > - pm_runtime_put_sync(&pdev->dev); > - pm_runtime_disable(&pdev->dev); > - pwmchip_remove(&pc->chip); > - return ret; > } > > static int ecap_pwm_remove(struct platform_device *pdev) > { > struct ecap_pwm_chip *pc = platform_get_drvdata(pdev); > > - pm_runtime_get_sync(&pdev->dev); > - /* > - * Due to hardware misbehaviour, acknowledge of the stop_req > - * is missing. Hence checking of the status bit skipped. > - */ > - pwmss_submodule_state_change(pdev->dev.parent, PWMSS_ECAPCLK_STOP_REQ); > - pm_runtime_put_sync(&pdev->dev); > - > pm_runtime_disable(&pdev->dev); > return pwmchip_remove(&pc->chip); > } > diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c > index 6a41e66..e09b1f0 100644 > --- a/drivers/pwm/pwm-tiehrpwm.c > +++ b/drivers/pwm/pwm-tiehrpwm.c > @@ -27,8 +27,6 @@ > #include > #include > > -#include "pwm-tipwmss.h" > - > /* EHRPWM registers and bits definitions */ > > /* Time base module registers */ > @@ -437,7 +435,6 @@ static int ehrpwm_pwm_probe(struct platform_device *pdev) > struct resource *r; > struct clk *clk; > struct ehrpwm_pwm_chip *pc; > - u16 status; > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > if (!pc) > @@ -487,27 +484,9 @@ static int ehrpwm_pwm_probe(struct platform_device *pdev) > } > > pm_runtime_enable(&pdev->dev); > - pm_runtime_get_sync(&pdev->dev); > - > - status = pwmss_submodule_state_change(pdev->dev.parent, > - PWMSS_EPWMCLK_EN); > - if (!(status & PWMSS_EPWMCLK_EN_ACK)) { > - dev_err(&pdev->dev, "PWMSS config space clock enable failed\n"); > - ret = -EINVAL; > - goto pwmss_clk_failure; > - } > - > - pm_runtime_put_sync(&pdev->dev); > > platform_set_drvdata(pdev, pc); > return 0; > - > -pwmss_clk_failure: > - pm_runtime_put_sync(&pdev->dev); > - pm_runtime_disable(&pdev->dev); > - pwmchip_remove(&pc->chip); > - clk_unprepare(pc->tbclk); > - return ret; > } > > static int ehrpwm_pwm_remove(struct platform_device *pdev) > @@ -516,14 +495,6 @@ static int ehrpwm_pwm_remove(struct platform_device *pdev) > > clk_unprepare(pc->tbclk); > > - pm_runtime_get_sync(&pdev->dev); > - /* > - * Due to hardware misbehaviour, acknowledge of the stop_req > - * is missing. Hence checking of the status bit skipped. > - */ > - pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ); > - pm_runtime_put_sync(&pdev->dev); > - > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > return pwmchip_remove(&pc->chip); > diff --git a/drivers/pwm/pwm-tipwmss.c b/drivers/pwm/pwm-tipwmss.c > index 5cf65a1..829f499 100644 > --- a/drivers/pwm/pwm-tipwmss.c > +++ b/drivers/pwm/pwm-tipwmss.c > @@ -22,32 +22,6 @@ > #include > #include > > -#include "pwm-tipwmss.h" > - > -#define PWMSS_CLKCONFIG 0x8 /* Clock gating reg */ > -#define PWMSS_CLKSTATUS 0xc /* Clock gating status reg */ > - > -struct pwmss_info { > - void __iomem *mmio_base; > - struct mutex pwmss_lock; > - u16 pwmss_clkconfig; > -}; > - > -u16 pwmss_submodule_state_change(struct device *dev, int set) > -{ > - struct pwmss_info *info = dev_get_drvdata(dev); > - u16 val; > - > - mutex_lock(&info->pwmss_lock); > - val = readw(info->mmio_base + PWMSS_CLKCONFIG); > - val |= set; > - writew(val , info->mmio_base + PWMSS_CLKCONFIG); > - mutex_unlock(&info->pwmss_lock); > - > - return readw(info->mmio_base + PWMSS_CLKSTATUS); > -} > -EXPORT_SYMBOL(pwmss_submodule_state_change); > - > static const struct of_device_id pwmss_of_match[] = { > { .compatible = "ti,am33xx-pwmss" }, > {}, > @@ -57,24 +31,10 @@ MODULE_DEVICE_TABLE(of, pwmss_of_match); > static int pwmss_probe(struct platform_device *pdev) > { > int ret; > - struct resource *r; > - struct pwmss_info *info; > struct device_node *node = pdev->dev.of_node; > > - info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); > - if (!info) > - return -ENOMEM; > - > - mutex_init(&info->pwmss_lock); > - > - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - info->mmio_base = devm_ioremap_resource(&pdev->dev, r); > - if (IS_ERR(info->mmio_base)) > - return PTR_ERR(info->mmio_base); > - > pm_runtime_enable(&pdev->dev); > pm_runtime_get_sync(&pdev->dev); > - platform_set_drvdata(pdev, info); > > /* Populate all the child nodes here... */ > ret = of_platform_populate(node, NULL, NULL, &pdev->dev); > @@ -86,30 +46,21 @@ static int pwmss_probe(struct platform_device *pdev) > > static int pwmss_remove(struct platform_device *pdev) > { > - struct pwmss_info *info = platform_get_drvdata(pdev); > - > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > - mutex_destroy(&info->pwmss_lock); > return 0; > } > > #ifdef CONFIG_PM_SLEEP > static int pwmss_suspend(struct device *dev) > { > - struct pwmss_info *info = dev_get_drvdata(dev); > - > - info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG); > pm_runtime_put_sync(dev); > return 0; > } > > static int pwmss_resume(struct device *dev) > { > - struct pwmss_info *info = dev_get_drvdata(dev); > - > pm_runtime_get_sync(dev); > - writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG); > return 0; > } > #endif > diff --git a/drivers/pwm/pwm-tipwmss.h b/drivers/pwm/pwm-tipwmss.h > deleted file mode 100644 > index 10ad804..0000000 > --- a/drivers/pwm/pwm-tipwmss.h > +++ /dev/null > @@ -1,39 +0,0 @@ > -/* > - * TI PWM Subsystem driver > - * > - * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ > - * > - * 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; either version 2 of the License, or > - * (at your option) any later version. > - * > - * This program is distributed in the hope that it will be useful, > - * but WITHOUT ANY WARRANTY; without even the implied warranty of > - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > - * GNU General Public License for more details. > - * > - */ > - > -#ifndef __TIPWMSS_H > -#define __TIPWMSS_H > - > -/* PWM substem clock gating */ > -#define PWMSS_ECAPCLK_EN BIT(0) > -#define PWMSS_ECAPCLK_STOP_REQ BIT(1) > -#define PWMSS_EPWMCLK_EN BIT(8) > -#define PWMSS_EPWMCLK_STOP_REQ BIT(9) > - > -#define PWMSS_ECAPCLK_EN_ACK BIT(0) > -#define PWMSS_EPWMCLK_EN_ACK BIT(8) > - > -#ifdef CONFIG_PWM_TIPWMSS > -extern u16 pwmss_submodule_state_change(struct device *dev, int set); > -#else > -static inline u16 pwmss_submodule_state_change(struct device *dev, int set) > -{ > - /* return success status value */ > - return 0xFFFF; > -} > -#endif > -#endif /* __TIPWMSS_H */ > gentle ping on this.