From patchwork Sun Jul 13 11:26:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Heiko_St=C3=BCbner?= X-Patchwork-Id: 4541111 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 563849F36A for ; Sun, 13 Jul 2014 11:28:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0F55A20179 for ; Sun, 13 Jul 2014 11:27:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D62F72017E for ; Sun, 13 Jul 2014 11:27:56 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X6HuA-0001VL-HL; Sun, 13 Jul 2014 11:25:18 +0000 Received: from gloria.sntech.de ([95.129.55.99]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X6Hu5-0000PY-8b for linux-arm-kernel@lists.infradead.org; Sun, 13 Jul 2014 11:25:16 +0000 Received: from ip9234425c.dynamic.kabel-deutschland.de ([146.52.66.92] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1X6HtZ-0000dd-98; Sun, 13 Jul 2014 13:24:41 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Jonathan Cameron Subject: [PATCH v4 1/2] iio: adc: add driver for Rockchip saradc Date: Sun, 13 Jul 2014 13:26:09 +0200 Message-ID: <3234956.d4q5ZB3IB8@diego> User-Agent: KMail/4.11.5 (Linux/3.13-1-amd64; KDE/4.11.3; x86_64; ; ) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140713_042515_478657_41082B93 X-CRM114-Status: GOOD ( 20.02 ) X-Spam-Score: -0.7 (/) Cc: Mark Rutland , devicetree@vger.kernel.org, huangtao@rock-chips.com, Pawel Moll , Ian Campbell , linux-iio@vger.kernel.org, Kumar Gala , linux-kernel@vger.kernel.org, Rob Herring , Peter Meerwald , Hartmut Knaack , =?utf-8?B?ZWRkaWUo6JSh5p6rKQ==?= , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The ADC is a 3-channel signal-ended 10-bit Successive Approximation Register (SAR) A/D Converter. It uses the supply and ground as its reference and converts the analog input signal into 10-bit binary digital codes. Signed-off-by: Heiko Stuebner --- changes since v3: - address comments from Jonathan Cameron - explicitly check for negative values in error checks - change Kconfig depends to ARCH_ROCKCHIP || (ARM && COMPILE_TEST) to prevent issues due to undefined writel_relaxed functions The previous check for OF was unecessary, as the only used function is of_property_read_u32, for which a stub is defined for the !OF case. changes since v2: - address more comments from Peter Meerwald mainly the missing info_mask_shared_by_type element changes since v1: - address comments from Peter Meerwald drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/rockchip_saradc.c | 315 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 326 insertions(+) create mode 100644 drivers/iio/adc/rockchip_saradc.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index a80d236..01c6ed6 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -187,6 +187,16 @@ config NAU7802 To compile this driver as a module, choose M here: the module will be called nau7802. +config ROCKCHIP_SARADC + tristate "Rockchip SARADC driver" + depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST) + help + Say yes here to build support for the SARADC found in SoCs from + Rockchip. + + To compile this driver as a module, choose M here: the + module will be called rockchip_saradc. + config TI_ADC081C tristate "Texas Instruments ADC081C021/027" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 9d60f2d..8e2932d 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o obj-$(CONFIG_NAU7802) += nau7802.o +obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c new file mode 100644 index 0000000..37218ea --- /dev/null +++ b/drivers/iio/adc/rockchip_saradc.c @@ -0,0 +1,315 @@ +/* + * Rockchip Successive Approximation Register (SAR) A/D Converter + * Copyright (C) 2014 ROCKCHIP, Inc. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SARADC_DATA 0x00 +#define SARADC_DATA_MASK 0x3ff + +#define SARADC_STAS 0x04 +#define SARADC_STAS_BUSY BIT(0) + +#define SARADC_CTRL 0x08 +#define SARADC_CTRL_IRQ_STATUS BIT(6) +#define SARADC_CTRL_IRQ_ENABLE BIT(5) +#define SARADC_CTRL_POWER_CTRL BIT(3) +#define SARADC_CTRL_CHN_MASK 0x7 + +#define SARADC_DLY_PU_SOC 0x0c +#define SARADC_DLY_PU_SOC_MASK 0x3f + +#define SARADC_BITS 10 +#define SARADC_TIMEOUT msecs_to_jiffies(100) + +struct rockchip_saradc { + void __iomem *regs; + struct clk *pclk; + struct clk *clk; + struct completion completion; + struct regulator *vref; + int vref_mv; + u16 last_val; +}; + +static int rockchip_saradc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct rockchip_saradc *info = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&indio_dev->mlock); + + /* Select the channel to be used and trigger conversion */ + writel_relaxed(0x08, info->regs + SARADC_DLY_PU_SOC); + writel(SARADC_CTRL_POWER_CTRL + | (chan->channel & SARADC_CTRL_CHN_MASK) + | SARADC_CTRL_IRQ_ENABLE, + info->regs + SARADC_CTRL); + + if (!wait_for_completion_timeout(&info->completion, + SARADC_TIMEOUT)) { + writel_relaxed(0, info->regs + SARADC_CTRL); + mutex_unlock(&indio_dev->mlock); + return -ETIMEDOUT; + } + + *val = info->last_val; + mutex_unlock(&indio_dev->mlock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = info->vref_mv; + *val2 = SARADC_BITS; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id) +{ + struct rockchip_saradc *info = (struct rockchip_saradc *)dev_id; + + /* Read value */ + info->last_val = readl_relaxed(info->regs + SARADC_DATA); + info->last_val &= SARADC_DATA_MASK; + + /* Clear irq & power down adc */ + writel_relaxed(0, info->regs + SARADC_CTRL); + + complete(&info->completion); + + return IRQ_HANDLED; +} + +static const struct iio_info rockchip_saradc_iio_info = { + .read_raw = rockchip_saradc_read_raw, + .driver_module = THIS_MODULE, +}; + +#define ADC_CHANNEL(_index, _id) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = _index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .datasheet_name = _id, \ +} + +static const struct iio_chan_spec rockchip_saradc_iio_channels[] = { + ADC_CHANNEL(0, "adc0"), + ADC_CHANNEL(1, "adc1"), + ADC_CHANNEL(2, "adc2"), +}; + +static int rockchip_saradc_probe(struct platform_device *pdev) +{ + struct rockchip_saradc *info = NULL; + struct device_node *np = pdev->dev.of_node; + struct iio_dev *indio_dev = NULL; + struct resource *mem; + int ret = -ENODEV; + int irq; + u32 rate; + + if (!np) + return ret; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); + if (!indio_dev) { + dev_err(&pdev->dev, "failed allocating iio device\n"); + return -ENOMEM; + } + info = iio_priv(indio_dev); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + info->regs = devm_request_and_ioremap(&pdev->dev, mem); + if (!info->regs) + return -ENOMEM; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no irq resource?\n"); + return irq; + } + + ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr, + 0, dev_name(&pdev->dev), info); + if (ret < 0) { + dev_err(&pdev->dev, "failed requesting irq %d\n", irq); + return ret; + } + + init_completion(&info->completion); + + info->pclk = devm_clk_get(&pdev->dev, "apb_pclk"); + if (IS_ERR(info->pclk)) { + dev_err(&pdev->dev, "failed to get pclk\n"); + return PTR_ERR(info->pclk); + } + + info->clk = devm_clk_get(&pdev->dev, "saradc"); + if (IS_ERR(info->clk)) { + dev_err(&pdev->dev, "failed to get adc clock\n"); + return PTR_ERR(info->clk); + } + + info->vref = devm_regulator_get(&pdev->dev, "vref"); + if (IS_ERR(info->vref)) { + dev_err(&pdev->dev, "failed to get regulator, %ld\n", + PTR_ERR(info->vref)); + return PTR_ERR(info->vref); + } + + /* use a default of 1MHz for the converter clock */ + ret = of_property_read_u32(np, "clock-frequency", &rate); + if (ret < 0) + rate = 1000000; + + ret = clk_set_rate(info->clk, rate); + if (ret < 0) { + dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret); + return ret; + } + + ret = regulator_enable(info->vref); + if (ret < 0) { + dev_err(&pdev->dev, "failed to enable vref regulator\n"); + return ret; + } + + ret = regulator_get_voltage(info->vref); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get regulator voltage\n"); + goto err_reg_voltage; + } + info->vref_mv = ret / 1000; + + ret = clk_prepare_enable(info->pclk); + if (ret < 0) { + dev_err(&pdev->dev, "failed to enable pclk\n"); + goto err_reg_voltage; + } + + ret = clk_prepare_enable(info->clk); + if (ret < 0) { + dev_err(&pdev->dev, "failed to enable converter clock\n"); + goto err_pclk; + } + + platform_set_drvdata(pdev, indio_dev); + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->dev.parent = &pdev->dev; + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->info = &rockchip_saradc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + indio_dev->channels = rockchip_saradc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels); + + ret = iio_device_register(indio_dev); + if (ret) + goto err_clk; + + return 0; + +err_clk: + clk_disable_unprepare(info->clk); +err_pclk: + clk_disable_unprepare(info->pclk); +err_reg_voltage: + regulator_disable(info->vref); + return ret; +} + +static int rockchip_saradc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct rockchip_saradc *info = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + clk_disable_unprepare(info->clk); + clk_disable_unprepare(info->pclk); + regulator_disable(info->vref); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int rockchip_saradc_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct rockchip_saradc *info = iio_priv(indio_dev); + + clk_disable_unprepare(info->clk); + clk_disable_unprepare(info->pclk); + regulator_disable(info->vref); + + return 0; +} + +static int rockchip_saradc_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct rockchip_saradc *info = iio_priv(indio_dev); + int ret; + + ret = regulator_enable(info->vref); + if (ret) + return ret; + + ret = clk_prepare_enable(info->pclk); + if (ret) + return ret; + + ret = clk_prepare_enable(info->clk); + if (ret) + return ret; + + return ret; +} +#endif + +static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops, + rockchip_saradc_suspend, rockchip_saradc_resume); + +static const struct of_device_id rockchip_saradc_match[] = { + { .compatible = "rockchip,saradc" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rockchip_saradc_match); + +static struct platform_driver rockchip_saradc_driver = { + .probe = rockchip_saradc_probe, + .remove = rockchip_saradc_remove, + .driver = { + .name = "rockchip-saradc", + .owner = THIS_MODULE, + .of_match_table = rockchip_saradc_match, + .pm = &rockchip_saradc_pm_ops, + }, +}; + +module_platform_driver(rockchip_saradc_driver);