From patchwork Wed May 29 08:46:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Sewior X-Patchwork-Id: 2628231 Return-Path: X-Original-To: patchwork-linux-input@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id DC175DF24C for ; Wed, 29 May 2013 08:47:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965214Ab3E2IrA (ORCPT ); Wed, 29 May 2013 04:47:00 -0400 Received: from www.linutronix.de ([62.245.132.108]:54972 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965224Ab3E2Iqr (ORCPT ); Wed, 29 May 2013 04:46:47 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.72) (envelope-from ) id 1Uhc1q-0004lV-Og; Wed, 29 May 2013 10:46:42 +0200 Date: Wed, 29 May 2013 10:46:42 +0200 From: Sebastian Andrzej Siewior To: linux-input@vger.kernel.org, linux-iio@vger.kernel.org Cc: Samuel Ortiz , Jonathan Cameron , Dmitry Torokhov , Felipe Balbi , Mark Brown Subject: Re: [PATCH 19/19 v2] mfd/ti_am335x_tscadc: add private lock/unlock function for regmap read/write Message-ID: <20130529084642.GA18273@linutronix.de> References: <1369681926-22185-1-git-send-email-bigeasy@linutronix.de> <1369681926-22185-20-git-send-email-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1369681926-22185-20-git-send-email-bigeasy@linutronix.de> X-Key-Id: 97C4700B X-Key-Fingerprint: 09E2 D1F3 9A3A FF13 C3D3 961C 0688 1C1E 97C4 700B User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Without this, devm_regmap_init_mmio() creates & uses a simple spin_lock() and this should be enough. Within the probe function the registers are read and written in process context. Later they are accessed from the ISR and lockdep complains because now the lock is taken suddenly with IRQs enabled. Currently I don't see any other way to keep lockdep quiet than doing this. Cc: Mark Brown Signed-off-by: Sebastian Andrzej Siewior --- v1..v2: pass a ti_tscadc_dev via lock arg drivers/mfd/ti_am335x_tscadc.c | 21 ++++++++++++++++++++- include/linux/mfd/ti_am335x_tscadc.h | 2 ++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c index 5e4076f..bd982e5 100644 --- a/drivers/mfd/ti_am335x_tscadc.c +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -42,11 +42,27 @@ static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg, regmap_write(tsadc->regmap_tscadc, reg, val); } +static void tscadc_lock_spinlock(void *__map) +{ + struct ti_tscadc_dev *tsadc = __map; + + spin_lock_irqsave(&tsadc->reg_map_lock, tsadc->reg_map_flags); +} + +static void tscadc_unlock_spinlock(void *__map) +{ + struct ti_tscadc_dev *tsadc = __map; + + spin_unlock_irqrestore(&tsadc->reg_map_lock, tsadc->reg_map_flags); +} + static const struct regmap_config tscadc_regmap_config = { .name = "ti_tscadc", .reg_bits = 32, .reg_stride = 4, .val_bits = 32, + .lock = tscadc_lock_spinlock, + .unlock = tscadc_unlock_spinlock, }; static void tscadc_idle_config(struct ti_tscadc_dev *config) @@ -69,6 +85,7 @@ static int ti_tscadc_probe(struct platform_device *pdev) int err, ctrl; int clk_value, clock_rate; int tsc_wires = 0, adc_channels = 0, total_channels; + struct regmap_config tscadc_regmap_cfg = tscadc_regmap_config; if (!pdev->dev.of_node) { dev_err(&pdev->dev, "Could not find valid DT data.\n"); @@ -110,6 +127,7 @@ static int ti_tscadc_probe(struct platform_device *pdev) } else tscadc->irq = err; + spin_lock_init(&tscadc->reg_map_lock); res = devm_request_mem_region(&pdev->dev, res->start, resource_size(res), pdev->name); if (!res) { @@ -124,8 +142,9 @@ static int ti_tscadc_probe(struct platform_device *pdev) return -ENOMEM; } + tscadc_regmap_cfg.lock_arg = tscadc; tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev, - tscadc->tscadc_base, &tscadc_regmap_config); + tscadc->tscadc_base, &tscadc_regmap_cfg); if (IS_ERR(tscadc->regmap_tscadc)) { dev_err(&pdev->dev, "regmap init failed\n"); err = PTR_ERR(tscadc->regmap_tscadc); diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index c985262..284e482 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -129,6 +129,8 @@ #define TSCADC_CELLS 2 struct ti_tscadc_dev { + spinlock_t reg_map_lock; + unsigned long reg_map_flags; struct device *dev; struct regmap *regmap_tscadc; void __iomem *tscadc_base;