On 09/13/2012 12:40 PM, Patil, Rachna wrote: > This patch adds support for TI's ADC driver. > This is a multifunctional device. > Analog input lines are provided on which > voltage measurements can be carried out. > You can have upto 8 input lines. >
Hi, couple of minor issues inline. > Signed-off-by: Patil, Rachna <[email protected]> > --- > Changes in v2: > Addressed review comments from Matthias Kaehlcke > > Changes in v3: > Addressed review comments from Jonathan Cameron. > Added comments, new line appropriately. > > drivers/iio/adc/Kconfig | 7 + > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ti_adc.c | 223 > ++++++++++++++++++++++++++++++++++ > drivers/mfd/ti_tscadc.c | 18 +++- > include/linux/mfd/ti_tscadc.h | 9 ++- > include/linux/platform_data/ti_adc.h | 14 ++ > 6 files changed, 270 insertions(+), 2 deletions(-) > create mode 100644 drivers/iio/adc/ti_adc.c > create mode 100644 include/linux/platform_data/ti_adc.h > [...] > + > +struct adc_device { Not really an issue, but I'd use a consistent function/struct prefix. Currently you use both "adc" and "tiadc" > + struct ti_tscadc_dev *mfd_tscadc; > + struct iio_dev *idev; idev is used only once in the remove callback. But you can get a pointer to it easily using platform_get_drvdata. So I'd remove it from the adc_device struct. > + int channels; > +}; > + > +static unsigned int adc_readl(struct adc_device *adc, unsigned int reg) > +{ > + return readl(adc->mfd_tscadc->tscadc_base + reg); > +} > + > +static void adc_writel(struct adc_device *adc, unsigned int reg, > + unsigned int val) > +{ > + writel(val, adc->mfd_tscadc->tscadc_base + reg); > +} > + > +static void adc_step_config(struct adc_device *adc_dev) > +{ > + unsigned int stepconfig; extra whitespace > + int i, channels = 0, steps; > + > + /* > + * There are 16 configurable steps and 8 analog input > + * lines available which are shared between Touchscreen and ADC. > + * > + * Steps backwards i.e. from 16 towards 0 are used by ADC > + * depending on number of input lines needed. > + * Channel would represent which analog input > + * needs to be given to ADC to digitalize data. > + */ > + > + steps = TOTAL_STEPS - adc_dev->channels; > + channels = TOTAL_CHANNELS - adc_dev->channels; > + > + stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1; > + > + for (i = (steps + 1); i <= TOTAL_STEPS; i++) { > + adc_writel(adc_dev, REG_STEPCONFIG(i), > + stepconfig | STEPCONFIG_INP(channels)); > + adc_writel(adc_dev, REG_STEPDELAY(i), > + STEPCONFIG_OPENDLY); > + channels++; > + } > + adc_writel(adc_dev, REG_SE, STPENB_STEPENB); > +} > + > [...] > + > +static const struct iio_info tiadc_info = { > + .read_raw = &tiadc_read_raw, .driver_module = THIS_MODULE, > +}; > + > +static int __devinit tiadc_probe(struct platform_device *pdev) > +{ > + struct iio_dev *idev; For consistency with other drivers please rename idev to indio_dev throughout the driver. > + int err; > + struct adc_device *adc_dev; > + struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data; > + struct mfd_tscadc_board *pdata; > + > + pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data; The cast should not be necessary. > + if (!pdata || !pdata->adc_init) { > + dev_err(tscadc_dev->dev, "Could not find platform data\n"); I'd still use pdev->dev for the device parameter here. Seeing a message printed by this driver for another device might be confusing. > + return -EINVAL; > + } > + > + idev = iio_device_alloc(sizeof(struct adc_device)); > + if (idev == NULL) { > + dev_err(&pdev->dev, "failed to allocate iio device.\n"); > + err = -ENOMEM; > + goto err_ret; > + } > + adc_dev = iio_priv(idev); > + > + tscadc_dev->adc = adc_dev; This there any reason why you need to store a pointer to the adc struct in the mfd struct? Is it going to be used outside of the adc driver? Currently it is, as far as I can see, only used in the remove callback and suspend/resume handlers. But there you can use iio_priv just as easily to get the pointer to the adc device struct and it certainly will be also be cleaner to do it that way. > + adc_dev->mfd_tscadc = tscadc_dev; > + adc_dev->idev = idev; > + adc_dev->channels = pdata->adc_init->adc_channels; > + > + idev->dev.parent = &pdev->dev; > + idev->name = dev_name(&pdev->dev); > + idev->modes = INDIO_DIRECT_MODE; > + idev->info = &tiadc_info; > + > + adc_step_config(adc_dev); > + > + err = tiadc_channel_init(idev, adc_dev->channels); > + if (err < 0) > + goto err_free_device; > + > + err = iio_device_register(idev); > + if (err) > + goto err_free_channels; > + > + dev_info(&pdev->dev, "attached adc driver\n"); I'd remove that line, it's just noise. > + platform_set_drvdata(pdev, idev); > + > + return 0; > + > +err_free_channels: > + tiadc_channels_remove(idev); > +err_free_device: > + iio_device_free(idev); > +err_ret: > + return err; > +} > + [...] > diff --git a/include/linux/platform_data/ti_adc.h > b/include/linux/platform_data/ti_adc.h > new file mode 100644 > index 0000000..5a89f1d > --- /dev/null > +++ b/include/linux/platform_data/ti_adc.h > @@ -0,0 +1,14 @@ > +#ifndef __LINUX_TI_ADC_H > +#define __LINUX_TI_ADC_H > + > +/** > + * struct adc_data ADC Input information > + * @adc_channels: Number of analog inputs > + * available for ADC. > + */ > + > +struct adc_data { The struct name might be a bit to generic. > + int adc_channels; It does not really matter, but considering that there hardly ever going to be a negative number of channels I'd make this unsigned. > +}; > + > +#endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
