From: maxime.ripard@free-electrons•com (Maxime Ripard)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver.
Date: Fri, 21 Oct 2011 19:54:05 +0200 [thread overview]
Message-ID: <4EA1B1BD.7000908@free-electrons.com> (raw)
In-Reply-To: <4E9FC916.2070800@metafoo.de>
Hi,
On 20/10/2011 09:09, Lars-Peter Clausen wrote:
> On 10/19/2011 06:18 PM, Maxime Ripard wrote:
>> Cc: Nicolas Ferre <nicolas.ferre@atmel•com>
>> Cc: Patrice Vilchez <patrice.vilchez@atmel•com>
>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons•com>
>> ---
>> [...]
>> +
>> +#define at91adc_reg_read(base, reg) __raw_readl((base) + (reg))
>> +#define at91adc_reg_write(base, reg, val) __raw_writel((val), (base) + (reg))
>
> Shouldn't this rather be {readl,writel}_relaxed?
Yep, corrected.
>> +
>> +struct at91adc_state {
>> + struct clk *clk;
>> + bool done;
>> + struct mutex lock;
>> + struct iio_chan_spec *channels;
>> + int nb_chan;
>> + int irq;
>> + wait_queue_head_t wq_data_avail;
>> + u16 lcdr;
>> + void __iomem *reg_base;
>> +
>> +};
>> +
>> +static irqreturn_t at91adc_eoc_trigger(int irq, void *private)
>> +{
>> + int chan;
>> + struct at91adc_state *st = private;
>> + struct iio_dev *idev = iio_priv_to_dev(st);
>> + unsigned int status = at91adc_reg_read(st->reg_base, AT91_ADC_SR);
>> +
>> + if (!(status & AT91_ADC_DRDY))
>> + return IRQ_HANDLED;
>> +
>> + for (chan = 0; chan < st->nb_chan; chan++) {
>> + if (status & AT91_ADC_EOC(chan)) {
>> + st->done = true;
>> + st->lcdr = at91adc_reg_read(st->reg_base,
>> + AT91_ADC_CHR(chan));
>> + }
>> + }
>> + wake_up_interruptible(&st->wq_data_avail);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int at91adc_channel_init(struct at91adc_state *st)
>> +{
>> + int ret = 0, i;
>> + st->channels = kzalloc(sizeof(struct iio_chan_spec) * st->nb_chan,
>> + GFP_KERNEL);
>
> kcalloc
Corrected
>> + if (st->channels == NULL)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < st->nb_chan; i++) {
>> + struct iio_chan_spec *chan = st->channels + i;
>> + chan->type = IIO_VOLTAGE;
>> + chan->indexed = 1;
>> + chan->channel = i;
>
>
> It probably makes sense to initialize scan_type as well.
Ah, didn't see that one, but yeah, you're right.
>> + ++ret;
>> + }
>> +
>> + return ret;
>
> Why do you need ret? Shouldn't this be just st->nb_chan?
The initial plan was to make sure all channels were initialised, but
obviously, my code isn't making such use of ret. You're right.
>> +}
>> +
>> +static int at91adc_read_raw(struct iio_dev *idev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2, long mask)
>> +{
>> + struct at91adc_state *st = iio_priv(idev);
>> +
>> + switch (mask) {
>> + case 0:
>> + mutex_lock(&st->lock);
>> +
>> + at91adc_reg_write(st->reg_base, AT91_ADC_CHER,
>> + AT91_ADC_CH(chan->channel));
>> + at91adc_reg_write(st->reg_base, AT91_ADC_IER,
>> + AT91_ADC_EOC(chan->channel));
>> + at91adc_reg_write(st->reg_base, AT91_ADC_CR, AT91_ADC_START);
>> +
>> + wait_event_interruptible(st->wq_data_avail, st->done);
>
> Its probably a good idea to add a timeout in case there is a problem with
> the hardware.
Indeed.
>> + *val = st->lcdr;
>> +
>> + at91adc_reg_write(st->reg_base, AT91_ADC_CHDR,
>> + AT91_ADC_CH(chan->channel));
>> + at91adc_reg_write(st->reg_base, AT91_ADC_IDR,
>> + AT91_ADC_EOC(chan->channel));
>> +
>> + st->lcdr = 0;
>> + st->done = false;
>> + mutex_unlock(&st->lock);
>> + return IIO_VAL_INT;
>> + default:
>> + break;
>> + }
>> + return -EINVAL;
>> +}
>> +
>> +static const struct iio_info at91adc_info = {
>> + .driver_module = THIS_MODULE,
>> + .read_raw = &at91adc_read_raw,
>> +};
>> +
>> +static int __devinit at91adc_probe(struct platform_device *pdev)
>> +{
>> + unsigned int prsc, mstrclk, ticks;
>> + int ret;
>> + struct iio_dev *idev;
>> + struct at91adc_state *st;
>> + struct resource *res;
>> + struct at91_adc_data *pdata = pdev->dev.platform_data;
>> +
>> + dev_dbg(&pdev->dev, "AT91ADC probed\n");
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!res) {
>> + dev_err(&pdev->dev, "No resource defined\n");
>> + ret = -ENXIO;
>> + goto error_ret;
>> + }
>> +
>> + idev = iio_allocate_device(sizeof(*st));
>> + if (idev == NULL) {
>> + dev_err(&pdev->dev, "Failed to allocate memory.\n");
>> + ret = -ENOMEM;
>> + goto error_ret;
>> + }
>> + platform_set_drvdata(pdev, idev);
>> +
>> + idev->dev.parent = &pdev->dev;
>> + idev->name = platform_get_device_id(pdev)->name;
>
> You don't use device ids. This should cause a NULL pointer deref? Maybe use
> dev_name(&pdev->dev) instead.
Ok.
>> + idev->modes = INDIO_DIRECT_MODE;
>> + idev->info = &at91adc_info;
>> +
>> +[...]
>> +}
>> +
>> +static int __devexit at91adc_remove(struct platform_device *pdev)
>> +{
>> + struct iio_dev *idev = platform_get_drvdata(pdev);
>> + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + struct at91adc_state *st = iio_priv(idev);
>> +
>> + free_irq(st->irq, st);
>> + iounmap(st->reg_base);
>> + release_mem_region(res->start, resource_size(res));
>> + iio_device_unregister(idev);
>> +
>
> The iio API changed a bit recently and uses a two stage unregistration now.
> You should call iio_device_unregister before freeing resources and
> iio_device_free afterwards.
Hmmm, I don't see the iio_device_free in Jonathan's git. Is it
iio_free_device, or should I use another git repo/branch as base ?
Thanks,
--
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2011-10-21 17:54 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-19 16:18 [PATCH] AT91: Add a driver for the ADC Maxime Ripard
2011-10-19 16:18 ` [PATCH 1/3] ARM: AT91: Add platform data for the ADCs Maxime Ripard
2011-10-19 16:18 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-10-19 16:42 ` Jonathan Cameron
2011-10-19 18:23 ` Maxime Ripard
2011-10-20 7:05 ` Thomas Petazzoni
2011-10-20 8:33 ` Jonathan Cameron
2011-10-20 8:49 ` Thomas Petazzoni
2011-10-20 9:19 ` Jonathan Cameron
2011-10-20 9:52 ` Mark Brown
2011-10-20 7:09 ` Lars-Peter Clausen
2011-10-21 17:54 ` Maxime Ripard [this message]
2011-10-21 17:55 ` Lars-Peter Clausen
2011-10-23 9:08 ` Jean-Christophe PLAGNIOL-VILLARD
2011-10-24 8:21 ` Maxime Ripard
2011-10-19 16:18 ` [PATCH 3/3] ARM: AT91: Add the ADC to the sam9g20ek board Maxime Ripard
2011-10-20 6:28 ` Alexander Stein
2011-10-21 17:47 ` Maxime Ripard
2011-10-20 7:14 ` Thomas Petazzoni
2011-11-03 10:11 ` [PATCHv2] AT91: Add a driver for the ADC Maxime Ripard
2011-11-03 10:11 ` [PATCH 1/3] ARM: AT91: Add platform data for the ADCs Maxime Ripard
2011-11-03 11:27 ` Linus Walleij
2011-11-03 16:27 ` Maxime Ripard
2011-11-03 16:38 ` Linus Walleij
2011-11-03 18:05 ` Jean-Christophe PLAGNIOL-VILLARD
2011-11-04 10:27 ` Jonathan Cameron
2011-11-04 10:36 ` Jonathan Cameron
2011-11-04 10:34 ` Jonathan Cameron
2011-11-04 15:22 ` Maxime Ripard
2011-11-04 16:28 ` Jonathan Cameron
2011-11-03 10:11 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-04 10:27 ` Jonathan Cameron
2011-11-04 16:29 ` Maxime Ripard
2011-11-04 16:40 ` Jonathan Cameron
2011-11-03 10:11 ` [PATCH 3/3] ARM: AT91: Add the ADC to the sam9g20ek board Maxime Ripard
2011-11-04 10:33 ` Jonathan Cameron
2011-11-04 11:25 ` Maxime Ripard
2011-11-04 15:52 ` Linus Walleij
2011-11-04 16:32 ` Jonathan Cameron
2011-11-07 16:08 ` [PATCHv3] AT91: Add a driver for the ADC Maxime Ripard
2011-11-07 16:08 ` [PATCH 1/3] ARM: AT91: Add platform data for the ADCs Maxime Ripard
2011-11-07 16:27 ` Jonathan Cameron
2011-11-08 13:19 ` Thomas Petazzoni
2011-11-07 16:08 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-08 13:30 ` Thomas Petazzoni
2011-11-07 16:08 ` [PATCH 3/3] ARM: AT91: Add the ADC to the sam9g20ek board Maxime Ripard
2011-11-09 10:19 ` [PATCHv4] AT91: Add a driver for the ADC Maxime Ripard
2011-11-09 10:19 ` [PATCH 1/3] ARM: AT91: Add platform data for the ADCs Maxime Ripard
2011-11-09 10:19 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-10 17:35 ` Jonathan Cameron
2011-11-11 12:34 ` Jonathan Cameron
2011-11-14 9:59 ` Maxime Ripard
2011-11-14 9:06 ` Maxime Ripard
2011-11-09 10:19 ` [PATCH 3/3] ARM: AT91: Add the ADC to the sam9g20ek board Maxime Ripard
2011-11-10 17:37 ` Jonathan Cameron
-- strict thread matches above, loose matches on Subject: below --
2011-11-14 10:06 [PATCHv5] AT91: Add a driver for the ADC Maxime Ripard
2011-11-14 10:06 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-14 11:30 ` Nicolas Ferre
2011-11-14 11:37 ` Marek Vasut
2011-11-14 14:23 ` Maxime Ripard
2011-11-14 17:30 [PATCH v6] AT91: Add a driver for the ADC Maxime Ripard
2011-11-14 17:30 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-14 21:32 ` Jonathan Cameron
2011-11-15 10:23 ` Maxime Ripard
2011-11-15 10:54 [PATCH v7] AT91: Add a driver for the ADC Maxime Ripard
2011-11-15 10:54 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-16 15:39 ` Maxime Ripard
2011-11-18 10:12 [PATCH v8] AT91: Add a driver for the ADC Maxime Ripard
2011-11-18 10:12 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-24 11:27 [PATCH v9] AT91: Add a driver for the ADC Maxime Ripard
2011-11-24 11:27 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-24 14:28 ` Jean-Christophe PLAGNIOL-VILLARD
2011-11-30 9:14 [PATCH v11] AT91: Add a driver for the ADC Maxime Ripard
2011-11-30 9:15 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-11-30 17:40 ` Arnd Bergmann
2011-12-02 13:17 [PATCH v12] AT91: Add a driver for the ADC Maxime Ripard
2011-12-02 13:17 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2011-12-14 10:01 [PATCH v13] AT91: Add a driver for the ADC Maxime Ripard
2011-12-14 10:01 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2012-01-16 21:36 [PATCH RESEND v13] AT91: Add a driver for the ADC Maxime Ripard
2012-01-16 21:36 ` [PATCH 2/3] ARM: AT91: IIO: Add AT91 ADC driver Maxime Ripard
2012-01-17 17:35 ` Arnd Bergmann
2012-01-17 19:08 ` Maxime Ripard
2012-01-18 10:27 ` Nicolas Ferre
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