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Message-ID: <53CB94C1.7080701@gmx.de> Date: Sun, 20 Jul 2014 12:06:57 +0200 From: Hartmut Knaack <knaack.h@....de> To: Heiko Stübner <heiko@...ech.de>, Jonathan Cameron <jic23@...nel.org> CC: Peter Meerwald <pmeerw@...erw.net>, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org, devicetree@...r.kernel.org, Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>, Mark Rutland <mark.rutland@....com>, Ian Campbell <ijc+devicetree@...lion.org.uk>, Kumar Gala <galak@...eaurora.org>, "eddie(蔡枫)" <cf@...k-chips.com>, huangtao@...k-chips.com Subject: Re: [PATCH v5 1/2] iio: adc: add driver for Rockchip saradc Heiko Stübner schrieb: > 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 <heiko@...ech.de> Reviewed-by: Hartmut Knaack <knaack.h@....de> > --- Looks good to me. The fact, that SARADC_DLY_PU_SOC_MASK is defined but never used should be fine under the given circumstances, that no datasheet with register definitions is publicly available. > changes since v4: > - address comments from Hartmut Knaack > - explain the DLY_PU_SOC value > - determine regulator voltage in IIO_CHAN_INFO_SCALE > - return ENODEV directly in the !np case > 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 | 316 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 327 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..9fa5653 > --- /dev/null > +++ b/drivers/iio/adc/rockchip_saradc.c > @@ -0,0 +1,316 @@ > +/* > + * 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 <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/of.h> > +#include <linux/clk.h> > +#include <linux/completion.h> > +#include <linux/regulator/consumer.h> > +#include <linux/iio/iio.h> > + > +#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; > + 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); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&indio_dev->mlock); > + > + /* 8 clock periods as delay between power up and start cmd */ > + writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC); > + > + /* Select the channel to be used and trigger conversion */ > + 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: > + ret = regulator_get_voltage(info->vref); > + if (ret < 0) { > + dev_err(&indio_dev->dev, "failed to get voltage\n"); > + return ret; > + } > + > + *val = ret / 1000; > + *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; > + int irq; > + u32 rate; > + > + if (!np) > + return -ENODEV; > + > + 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 = 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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