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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-05 18:16:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-05 18:16:23 -0700
commitc6a677c6f37bb7abc85ba7e3465e82b9f7eb1d91 (patch)
tree9d0d4bb2e150837297cddc5be7f1b4950e9ab228 /drivers/iio/adc/lpc32xx_adc.c
parente87d51ac61f88ae44fe14b34abe08566032d726b (diff)
parent11270059e8d0b6f80801fac910c4ef751ca05c4c (diff)
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Merge tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO updates from Greg KH: "Here is the big staging tree update for 4.12-rc1. It's a big one, adding about 350k new lines of crap^Wcode, mostly all in a big dump of media drivers from Intel. But there's other new drivers in here as well, yet-another-wifi driver, new IIO drivers, and a new crypto accelerator. We also deleted a bunch of stuff, mostly in patch cleanups, but also the Android ION code has shrunk a lot, and the Android low memory killer driver was finally deleted, much to the celebration of the -mm developers. All of these have been in linux-next with a few build issues that will show up when you merge to your tree" Merge conflicts in the new rtl8723bs driver (due to the wifi changes this merge window) handled as per linux-next, courtesy of Stephen Rothwell. * tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1182 commits) staging: fsl-mc/dpio: add cpu <--> LE conversion for dpaa2_fd staging: ks7010: remove line continuations in quoted strings staging: vt6656: use tabs instead of spaces staging: android: ion: Fix unnecessary initialization of static variable staging: media: atomisp: fix range checking on clk_num staging: media: atomisp: fix misspelled word in comment staging: media: atomisp: kmap() can't fail staging: atomisp: remove #ifdef for runtime PM functions staging: atomisp: satm include directory is gone atomisp: remove some more unused files atomisp: remove hmm_load/store/clear indirections atomisp: kill off mmgr_free atomisp: clean up the hmm init/cleanup indirections atomisp: handle allocation calls before init in the hmm layer staging: fsl-dpaa2/eth: Add maintainer for Ethernet driver staging: fsl-dpaa2/eth: Add TODO file staging: fsl-dpaa2/eth: Add trace points staging: fsl-dpaa2/eth: Add driver specific stats staging: fsl-dpaa2/eth: Add ethtool support staging: fsl-dpaa2/eth: Add Freescale DPAA2 Ethernet driver ...
Diffstat (limited to 'drivers/iio/adc/lpc32xx_adc.c')
-rw-r--r--drivers/iio/adc/lpc32xx_adc.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
new file mode 100644
index 000000000000..0de709b4288b
--- /dev/null
+++ b/drivers/iio/adc/lpc32xx_adc.c
@@ -0,0 +1,219 @@
+/*
+ * lpc32xx_adc.c - Support for ADC in LPC32XX
+ *
+ * 3-channel, 10-bit ADC
+ *
+ * Copyright (C) 2011, 2012 Roland Stigge <stigge@antcom.de>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/completion.h>
+#include <linux/of.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+/*
+ * LPC32XX registers definitions
+ */
+#define LPC32XXAD_SELECT(x) ((x) + 0x04)
+#define LPC32XXAD_CTRL(x) ((x) + 0x08)
+#define LPC32XXAD_VALUE(x) ((x) + 0x48)
+
+/* Bit definitions for LPC32XXAD_SELECT: */
+/* constant, always write this value! */
+#define LPC32XXAD_REFm 0x00000200
+/* constant, always write this value! */
+#define LPC32XXAD_REFp 0x00000080
+ /* multiple of this is the channel number: 0, 1, 2 */
+#define LPC32XXAD_IN 0x00000010
+/* constant, always write this value! */
+#define LPC32XXAD_INTERNAL 0x00000004
+
+/* Bit definitions for LPC32XXAD_CTRL: */
+#define LPC32XXAD_STROBE 0x00000002
+#define LPC32XXAD_PDN_CTRL 0x00000004
+
+/* Bit definitions for LPC32XXAD_VALUE: */
+#define LPC32XXAD_VALUE_MASK 0x000003FF
+
+#define LPC32XXAD_NAME "lpc32xx-adc"
+
+struct lpc32xx_adc_state {
+ void __iomem *adc_base;
+ struct clk *clk;
+ struct completion completion;
+
+ u32 value;
+};
+
+static int lpc32xx_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long mask)
+{
+ struct lpc32xx_adc_state *st = iio_priv(indio_dev);
+
+ if (mask == IIO_CHAN_INFO_RAW) {
+ mutex_lock(&indio_dev->mlock);
+ clk_prepare_enable(st->clk);
+ /* Measurement setup */
+ __raw_writel(LPC32XXAD_INTERNAL | (chan->address) |
+ LPC32XXAD_REFp | LPC32XXAD_REFm,
+ LPC32XXAD_SELECT(st->adc_base));
+ /* Trigger conversion */
+ __raw_writel(LPC32XXAD_PDN_CTRL | LPC32XXAD_STROBE,
+ LPC32XXAD_CTRL(st->adc_base));
+ wait_for_completion(&st->completion); /* set by ISR */
+ clk_disable_unprepare(st->clk);
+ *val = st->value;
+ mutex_unlock(&indio_dev->mlock);
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info lpc32xx_adc_iio_info = {
+ .read_raw = &lpc32xx_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#define LPC32XX_ADC_CHANNEL(_index) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = _index, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .address = LPC32XXAD_IN * _index, \
+ .scan_index = _index, \
+}
+
+static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
+ LPC32XX_ADC_CHANNEL(0),
+ LPC32XX_ADC_CHANNEL(1),
+ LPC32XX_ADC_CHANNEL(2),
+};
+
+static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
+{
+ struct lpc32xx_adc_state *st = dev_id;
+
+ /* Read value and clear irq */
+ st->value = __raw_readl(LPC32XXAD_VALUE(st->adc_base)) &
+ LPC32XXAD_VALUE_MASK;
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+}
+
+static int lpc32xx_adc_probe(struct platform_device *pdev)
+{
+ struct lpc32xx_adc_state *st = NULL;
+ struct resource *res;
+ int retval = -ENODEV;
+ struct iio_dev *iodev = NULL;
+ int irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get platform I/O memory\n");
+ return -ENXIO;
+ }
+
+ iodev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+ if (!iodev)
+ return -ENOMEM;
+
+ st = iio_priv(iodev);
+
+ st->adc_base = devm_ioremap(&pdev->dev, res->start,
+ resource_size(res));
+ if (!st->adc_base) {
+ dev_err(&pdev->dev, "failed mapping memory\n");
+ return -EBUSY;
+ }
+
+ st->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(st->clk)) {
+ dev_err(&pdev->dev, "failed getting clock\n");
+ return PTR_ERR(st->clk);
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0) {
+ dev_err(&pdev->dev, "failed getting interrupt resource\n");
+ return -ENXIO;
+ }
+
+ retval = devm_request_irq(&pdev->dev, irq, lpc32xx_adc_isr, 0,
+ LPC32XXAD_NAME, st);
+ if (retval < 0) {
+ dev_err(&pdev->dev, "failed requesting interrupt\n");
+ return retval;
+ }
+
+ platform_set_drvdata(pdev, iodev);
+
+ init_completion(&st->completion);
+
+ iodev->name = LPC32XXAD_NAME;
+ iodev->dev.parent = &pdev->dev;
+ iodev->info = &lpc32xx_adc_iio_info;
+ iodev->modes = INDIO_DIRECT_MODE;
+ iodev->channels = lpc32xx_adc_iio_channels;
+ iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
+
+ retval = devm_iio_device_register(&pdev->dev, iodev);
+ if (retval)
+ return retval;
+
+ dev_info(&pdev->dev, "LPC32XX ADC driver loaded, IRQ %d\n", irq);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id lpc32xx_adc_match[] = {
+ { .compatible = "nxp,lpc3220-adc" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_adc_match);
+#endif
+
+static struct platform_driver lpc32xx_adc_driver = {
+ .probe = lpc32xx_adc_probe,
+ .driver = {
+ .name = LPC32XXAD_NAME,
+ .of_match_table = of_match_ptr(lpc32xx_adc_match),
+ },
+};
+
+module_platform_driver(lpc32xx_adc_driver);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("LPC32XX ADC driver");
+MODULE_LICENSE("GPL");