From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030357AbcIVSgn (ORCPT ); Thu, 22 Sep 2016 14:36:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57246 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965874AbcIVRo4 (ORCPT ); Thu, 22 Sep 2016 13:44:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Caesar Wang , Jonathan Cameron , Heiko Stuebner , Rob Herring , linux-iio@vger.kernel.org, linux-rockchip@lists.infradead.org, Guenter Roeck Subject: [PATCH 4.7 069/184] iio: adc: rockchip_saradc: reset saradc controller before programming it Date: Thu, 22 Sep 2016 19:40:03 +0200 Message-Id: <20160922174051.671741226@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160922174048.653794923@linuxfoundation.org> References: <20160922174048.653794923@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Caesar Wang commit 543852af8e5902aee8f7c72c89e1513663e0f696 upstream. SARADC controller needs to be reset before programming it, otherwise it will not function properly. Signed-off-by: Caesar Wang Cc: Jonathan Cameron Cc: Heiko Stuebner Cc: Rob Herring Cc: linux-iio@vger.kernel.org Cc: linux-rockchip@lists.infradead.org Tested-by: Guenter Roeck Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt | 7 ++ drivers/iio/adc/Kconfig | 1 drivers/iio/adc/rockchip_saradc.c | 30 ++++++++++ 3 files changed, 38 insertions(+) --- a/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt +++ b/Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt @@ -16,6 +16,11 @@ Required properties: - vref-supply: The regulator supply ADC reference voltage. - #io-channel-cells: Should be 1, see ../iio-bindings.txt +Optional properties: +- resets: Must contain an entry for each entry in reset-names if need support + this option. See ../reset/reset.txt for details. +- reset-names: Must include the name "saradc-apb". + Example: saradc: saradc@2006c000 { compatible = "rockchip,saradc"; @@ -23,6 +28,8 @@ Example: interrupts = ; clocks = <&cru SCLK_SARADC>, <&cru PCLK_SARADC>; clock-names = "saradc", "apb_pclk"; + resets = <&cru SRST_SARADC>; + reset-names = "saradc-apb"; #io-channel-cells = <1>; vref-supply = <&vcc18>; }; --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -377,6 +377,7 @@ config QCOM_SPMI_VADC config ROCKCHIP_SARADC tristate "Rockchip SARADC driver" depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST) + depends on RESET_CONTROLLER help Say yes here to build support for the SARADC found in SoCs from Rockchip. --- a/drivers/iio/adc/rockchip_saradc.c +++ b/drivers/iio/adc/rockchip_saradc.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #include @@ -53,6 +55,7 @@ struct rockchip_saradc { struct clk *clk; struct completion completion; struct regulator *vref; + struct reset_control *reset; const struct rockchip_saradc_data *data; u16 last_val; }; @@ -190,6 +193,16 @@ static const struct of_device_id rockchi }; MODULE_DEVICE_TABLE(of, rockchip_saradc_match); +/** + * Reset SARADC Controller. + */ +static void rockchip_saradc_reset_controller(struct reset_control *reset) +{ + reset_control_assert(reset); + usleep_range(10, 20); + reset_control_deassert(reset); +} + static int rockchip_saradc_probe(struct platform_device *pdev) { struct rockchip_saradc *info = NULL; @@ -218,6 +231,20 @@ static int rockchip_saradc_probe(struct if (IS_ERR(info->regs)) return PTR_ERR(info->regs); + /* + * The reset should be an optional property, as it should work + * with old devicetrees as well + */ + info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb"); + if (IS_ERR(info->reset)) { + ret = PTR_ERR(info->reset); + if (ret != -ENOENT) + return ret; + + dev_dbg(&pdev->dev, "no reset control found\n"); + info->reset = NULL; + } + init_completion(&info->completion); irq = platform_get_irq(pdev, 0); @@ -252,6 +279,9 @@ static int rockchip_saradc_probe(struct return PTR_ERR(info->vref); } + if (info->reset) + rockchip_saradc_reset_controller(info->reset); + /* * Use a default value for the converter clock. * This may become user-configurable in the future.