// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann * * This is the driver for the imx25 GCQ (Generic Conversion Queue) * connected to the imx25 ADC. */ #include #include #include #include #include #include #include #include #include #include #include #define MX25_GCQ_TIMEOUT (msecs_to_jiffies(2000)) static const char * const driver_name = "mx25-gcq"; 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; struct clk *clk; int irq; struct regulator *vref[4]; u32 channel_vref_mv[MX25_NUM_CFGS]; /* * Lock to protect the device state during a potential concurrent * read access from userspace. Reading a raw value requires a sequence * of register writes, then a wait for a completion callback, * and finally a register read, during which userspace could issue * another read request. This lock protects a read access from * ocurring before another one has finished. */ struct mutex lock; }; #define MX25_CQG_CHAN(chan, id) {\ .type = IIO_VOLTAGE,\ .indexed = 1,\ .channel = chan,\ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_SCALE),\ .datasheet_name = id,\ } static const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = { MX25_CQG_CHAN(MX25_CFG_XP, "xp"), MX25_CQG_CHAN(MX25_CFG_YP, "yp"), MX25_CQG_CHAN(MX25_CFG_XN, "xn"), MX25_CQG_CHAN(MX25_CFG_YN, "yn"), MX25_CQG_CHAN(MX25_CFG_WIPER, "wiper"), MX25_CQG_CHAN(MX25_CFG_INAUX0, "inaux0"), MX25_CQG_CHAN(MX25_CFG_INAUX1, "inaux1"), MX25_CQG_CHAN(MX25_CFG_INAUX2, "inaux2"), }; static const char * const mx25_gcq_refp_names[] = { [MX25_ADC_REFP_YP] = "yp", [MX25_ADC_REFP_XP] = "xp", [MX25_ADC_REFP_INT] = "int", [MX25_ADC_REFP_EXT] = "ext", }; 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_set_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ); complete(&priv->completed); } /* Disable conversion queue run */ regmap_clear_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS); /* 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 time_left; 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_clear_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ); /* Trigger queue for one run */ regmap_set_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS); time_left = wait_for_completion_interruptible_timeout( &priv->completed, MX25_GCQ_TIMEOUT); if (time_left < 0) { dev_err(dev, "ADC wait for measurement failed\n"); return time_left; } else if (time_left == 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; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&priv->lock); ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val); mutex_unlock(&priv->lock); 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_ext_regulator_setup(struct device *dev, struct mx25_gcq_priv *priv, u32 refp) { char reg_name[12]; int ret; if (priv->vref[refp]) return 0; ret = snprintf(reg_name, sizeof(reg_name), "vref-%s", mx25_gcq_refp_names[refp]); if (ret < 0) return ret; priv->vref[refp] = devm_regulator_get_optional(dev, reg_name); if (IS_ERR(priv->vref[refp])) return dev_err_probe(dev, PTR_ERR(priv->vref[refp]), "Error, trying to use external voltage reference without a %s regulator.", reg_name); return 0; } static int mx25_gcq_setup_cfgs(struct platform_device *pdev, struct mx25_gcq_priv *priv) { struct device *dev = &pdev->dev; int ret, i; /* * 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); device_for_each_child_node_scoped(dev, child) { u32 reg; u32 refp = MX25_ADCQ_CFG_REFP_INT; u32 refn = MX25_ADCQ_CFG_REFN_NGND2; ret = fwnode_property_read_u32(child, "reg", ®); if (ret) return dev_err_probe(dev, ret, "Failed to get reg property\n"); if (reg >= MX25_NUM_CFGS) return dev_err_probe(dev, -EINVAL, "reg value is greater than the number of available configuration registers\n"); fwnode_property_read_u32(child, "fsl,adc-refp", &refp); fwnode_property_read_u32(child, "fsl,adc-refn", &refn); switch (refp) { case MX25_ADC_REFP_EXT: case MX25_ADC_REFP_XP: case MX25_ADC_REFP_YP: ret = mx25_gcq_ext_regulator_setup(&pdev->dev, priv, refp); if (ret) return ret; priv->channel_vref_mv[reg] = regulator_get_voltage(priv->vref[refp]); /* Conversion from uV to mV */ priv->channel_vref_mv[reg] /= 1000; break; case MX25_ADC_REFP_INT: priv->channel_vref_mv[reg] = 2500; break; default: return dev_err_probe(dev, -EINVAL, "Invalid positive reference %d\n", refp); } /* * 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) return dev_err_probe(dev, -EINVAL, "Invalid fsl,adc-refp property value\n"); if ((refn & MX25_ADCQ_CFG_REFN_MASK) != refn) return dev_err_probe(dev, -EINVAL, "Invalid fsl,adc-refn property value\n"); regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg), MX25_ADCQ_CFG_REFP_MASK | MX25_ADCQ_CFG_REFN_MASK, refp | refn); } regmap_set_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST); regmap_write(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS); return 0; } static void mx25_gcq_reg_disable(void *reg) { regulator_disable(reg); } /* Custom handling needed as this driver doesn't own the clock */ static void mx25_gcq_clk_disable(void *clk) { clk_disable_unprepare(clk); } 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; void __iomem *mem; int ret; int i; indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); if (!indio_dev) return -ENOMEM; priv = iio_priv(indio_dev); mem = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(mem)) return PTR_ERR(mem); priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig); if (IS_ERR(priv->regs)) return dev_err_probe(dev, PTR_ERR(priv->regs), "Failed to initialize regmap\n"); mutex_init(&priv->lock); init_completion(&priv->completed); ret = mx25_gcq_setup_cfgs(pdev, priv); if (ret) return ret; for (i = 0; i != 4; ++i) { if (!priv->vref[i]) continue; ret = regulator_enable(priv->vref[i]); if (ret) return ret; ret = devm_add_action_or_reset(dev, mx25_gcq_reg_disable, priv->vref[i]); if (ret) return ret; } priv->clk = tsadc->clk; ret = clk_prepare_enable(priv->clk); if (ret) return dev_err_probe(dev, ret, "Failed to enable clock\n"); ret = devm_add_action_or_reset(dev, mx25_gcq_clk_disable, priv->clk); if (ret) return ret; ret = platform_get_irq(pdev, 0); if (ret < 0) return ret; priv->irq = ret; ret = devm_request_irq(dev, priv->irq, mx25_gcq_irq, 0, pdev->name, priv); if (ret) return dev_err_probe(dev, ret, "Failed requesting IRQ\n"); indio_dev->channels = mx25_gcq_channels; indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels); indio_dev->info = &mx25_gcq_iio_info; indio_dev->name = driver_name; ret = devm_iio_device_register(dev, indio_dev); if (ret) return dev_err_probe(dev, ret, "Failed to register iio device\n"); return 0; } static const struct of_device_id mx25_gcq_ids[] = { { .compatible = "fsl,imx25-gcq", }, { /* Sentinel */ } }; MODULE_DEVICE_TABLE(of, mx25_gcq_ids); static struct platform_driver mx25_gcq_driver = { .driver = { .name = "mx25-gcq", .of_match_table = mx25_gcq_ids, }, .probe = mx25_gcq_probe, }; module_platform_driver(mx25_gcq_driver); MODULE_DESCRIPTION("ADC driver for Freescale mx25"); MODULE_AUTHOR("Markus Pargmann "); MODULE_LICENSE("GPL v2");