@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ * This is the driver for the imx25 GCQ (Generic Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <dt-bindings/iio/adc/fsl-imx25-gcq.h>
+#include <linux/clk.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define MX25_GCQ_TIMEOUT (msecs_to_jiffies(2000))
+
+enum mx25_gcq_cfgs {
+ MX25_CFG_XP = 0,
+ MX25_CFG_YP,
+ MX25_CFG_XN,
+ MX25_CFG_YN,
+ MX25_CFG_WIPER,
+ MX25_CFG_INAUX0,
+ MX25_CFG_INAUX1,
+ MX25_CFG_INAUX2,
+ MX25_NUM_CFGS,
+};
+
+struct mx25_gcq_priv {
+ struct regmap *regs;
+ struct completion completed;
+ unsigned int settling_time;
+ struct clk *clk;
+ int irq;
+ struct regulator *ext_vref;
+ u32 channel_vref_mv[MX25_NUM_CFGS];
+};
+
+#define MX25_CQG_CHAN(chan, id) {\
+ .type = IIO_VOLTAGE,\
+ .indexed = 1,\
+ .channel = chan,\
+ .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 mx25_gcq_channels[MX25_NUM_CFGS] = {
+ MX25_CQG_CHAN(0, "xp"),
+ MX25_CQG_CHAN(1, "yp"),
+ MX25_CQG_CHAN(2, "xn"),
+ MX25_CQG_CHAN(3, "yn"),
+ MX25_CQG_CHAN(4, "wiper"),
+ MX25_CQG_CHAN(5, "inaux0"),
+ MX25_CQG_CHAN(6, "inaux1"),
+ MX25_CQG_CHAN(7, "inaux2"),
+};
+
+static irqreturn_t mx25_gcq_irq(int irq, void *data)
+{
+ struct mx25_gcq_priv *priv = data;
+ u32 stats;
+
+ regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+
+ if (stats & MX25_ADCQ_SR_EOQ) {
+ regmap_update_bits(priv->regs, MX25_ADCQ_MR,
+ MX25_ADCQ_MR_EOQ_IRQ, MX25_ADCQ_MR_EOQ_IRQ);
+ complete(&priv->completed);
+ }
+
+ /* Disable conversion queue run */
+ regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+
+ /* Acknowledge all possible irqs */
+ regmap_write(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+ MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
+ MX25_ADCQ_SR_EOQ | MX25_ADCQ_SR_PD);
+
+ return IRQ_HANDLED;
+}
+
+static int mx25_gcq_get_raw_value(struct device *dev,
+ struct iio_chan_spec const *chan,
+ struct mx25_gcq_priv *priv,
+ int *val)
+{
+ long timeout;
+ u32 data;
+
+ /* Setup the configuration we want to use */
+ regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+ MX25_ADCQ_ITEM(0, chan->channel));
+
+ regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ, 0);
+
+ /* Trigger queue for one run */
+ regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
+ MX25_ADCQ_CR_FQS);
+
+ timeout = wait_for_completion_interruptible_timeout(
+ &priv->completed, MX25_GCQ_TIMEOUT);
+ if (timeout < 0) {
+ dev_err(dev,
+ "ADC wait for measurement failed\n");
+ return timeout;
+ } else if (timeout == 0) {
+ dev_err(dev, "ADC timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+
+ *val = MX25_ADCQ_FIFO_DATA(data);
+
+ return IIO_VAL_INT;
+}
+
+static int mx25_gcq_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct mx25_gcq_priv *priv = iio_priv(indio_dev);
+ int ret = 0;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&indio_dev->mlock);
+ ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val);
+ mutex_unlock(&indio_dev->mlock);
+ return ret;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = priv->channel_vref_mv[chan->channel];
+ *val2 = 12;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info mx25_gcq_iio_info = {
+ .read_raw = mx25_gcq_read_raw,
+};
+
+static const struct regmap_config mx25_gcq_regconfig = {
+ .max_register = 0x5c,
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
+ struct mx25_gcq_priv *priv)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *child;
+ struct device *dev = &pdev->dev;
+ int ret, i;
+ bool external_ref_used = false;
+
+ /*
+ * Setup all configurations registers with a default conversion
+ * configuration for each input
+ */
+ for (i = 0; i < MX25_NUM_CFGS; ++i)
+ regmap_write(priv->regs, MX25_ADCQ_CFG(i),
+ MX25_ADCQ_CFG_YPLL_OFF |
+ MX25_ADCQ_CFG_XNUR_OFF |
+ MX25_ADCQ_CFG_XPUL_OFF |
+ MX25_ADCQ_CFG_REFP_INT |
+ MX25_ADCQ_CFG_IN(i) |
+ MX25_ADCQ_CFG_REFN_NGND2);
+
+ for_each_child_of_node(np, child) {
+ u32 reg;
+ u32 refp = MX25_ADCQ_CFG_REFP_INT;
+ u32 refn = MX25_ADCQ_CFG_REFN_NGND2;
+
+ ret = of_property_read_u32(child, "reg", ®);
+ if (ret) {
+ dev_err(dev, "Failed to get reg property\n");
+ return ret;
+ }
+
+ if (reg >= MX25_NUM_CFGS) {
+ dev_err(dev,
+ "reg value is greater than the number of available configuration registers\n");
+ return -EINVAL;
+ }
+
+ of_property_read_u32(child, "fsl,adc-refp", &refp);
+ of_property_read_u32(child, "fsl,adc-refn", &refn);
+
+ if (refp == MX25_ADC_REFP_EXT)
+ external_ref_used = true;
+
+ /*
+ * Shift the read values to the correct positions within the
+ * register.
+ */
+ refp = MX25_ADCQ_CFG_REFP(refp);
+ refn = MX25_ADCQ_CFG_REFN(refn);
+
+ if ((refp & MX25_ADCQ_CFG_REFP_MASK) != refp) {
+ dev_err(dev, "Invalid fsl,adc-refp property value\n");
+ return -EINVAL;
+ }
+ if ((refn & MX25_ADCQ_CFG_REFN_MASK) != refn) {
+ dev_err(dev, "Invalid fsl,adc-refn property value");
+ return -EINVAL;
+ }
+
+ regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
+ MX25_ADCQ_CFG_REFP_MASK |
+ MX25_ADCQ_CFG_REFN_MASK,
+ refp | refn);
+ }
+ regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+ MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST,
+ MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
+
+ regmap_write(priv->regs, MX25_ADCQ_CR,
+ MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS);
+
+ if (external_ref_used) {
+ priv->ext_vref = devm_regulator_get(&pdev->dev, "vref");
+ if (IS_ERR(priv->ext_vref)) {
+ dev_err(&pdev->dev, "Failed to get regulator for vref although the external reference voltage is used.\n");
+ return PTR_ERR(priv->ext_vref);
+ }
+ }
+
+ return 0;
+}
+
+static int mx25_gcq_probe(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev;
+ struct mx25_gcq_priv *priv;
+ struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ void __iomem *mem;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ priv = iio_priv(indio_dev);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mem = devm_ioremap_resource(dev, res);
+ if (!mem)
+ return -ENOMEM;
+
+ priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig);
+ if (IS_ERR(priv->regs)) {
+ dev_err(dev, "Failed to initialize regmap\n");
+ return PTR_ERR(priv->regs);
+ }
+
+ init_completion(&priv->completed);
+
+ ret = mx25_gcq_setup_cfgs(pdev, priv);
+ if (ret)
+ return ret;
+
+ if (!IS_ERR_OR_NULL(priv->ext_vref)) {
+ ret = regulator_enable(priv->ext_vref);
+ if (ret)
+ return ret;
+ }
+
+ priv->clk = tsadc->clk;
+ ret = clk_prepare_enable(priv->clk);
+ if (ret) {
+ dev_err(dev, "Failed to enable clock\n");
+ return ret;
+ }
+
+ priv->irq = platform_get_irq(pdev, 0);
+ if (priv->irq <= 0) {
+ dev_err(dev, "Failed to get IRQ\n");
+ ret = priv->irq;
+ goto err_clk_unprepare;
+ }
+
+ ret = request_irq(priv->irq, mx25_gcq_irq, 0, pdev->name, priv);
+ if (ret) {
+ dev_err(dev, "Failed requesting IRQ\n");
+ goto err_clk_unprepare;
+ }
+
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->channels = mx25_gcq_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
+ indio_dev->info = &mx25_gcq_iio_info;
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(dev, "Failed to register iio device\n");
+ goto err_irq_free;
+ }
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ return 0;
+
+err_irq_free:
+ free_irq(priv->irq, (void *)priv);
+err_clk_unprepare:
+ clk_disable_unprepare(priv->clk);
+ return ret;
+}
+
+static int mx25_gcq_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct mx25_gcq_priv *priv = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ free_irq(priv->irq, priv);
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static struct of_device_id mx25_gcq_ids[] = {
+ { .compatible = "fsl,imx25-gcq", },
+ { /* Sentinel */ }
+};
+
+static struct platform_driver mx25_gcq_driver = {
+ .driver = {
+ .name = "mx25-gcq",
+ .of_match_table = mx25_gcq_ids,
+ },
+ .probe = mx25_gcq_probe,
+ .remove = mx25_gcq_remove,
+};
+module_platform_driver(mx25_gcq_driver);
+
+MODULE_DESCRIPTION("ADC driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
+MODULE_LICENSE("GPL v2");