This patch adds basic driver implementation for Broadcom's static adc controller used in iProc SoC's family. Signed-off-by: Raveendra Padasalagi <raveendra.padasalagi@xxxxxxxxxxxx> Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx> Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx> --- drivers/iio/adc/Kconfig | 12 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/bcm_iproc_adc.c | 556 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 569 insertions(+) create mode 100644 drivers/iio/adc/bcm_iproc_adc.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 25378c5..86ce29d 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -160,6 +160,18 @@ config BERLIN2_ADC Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for temperature measurement. +config BCM_IPROC_ADC + tristate "Broadcom IPROC ADC driver" + depends on ARCH_BCM_IPROC || COMPILE_TEST + depends on MFD_SYSCON + default ARCH_BCM_CYGNUS + help + Say Y here if you want to add support for the Broadcom static + ADC driver. + + The driver allows the user to read the values + from the static ADC. + config CC10001_ADC tristate "Cosmic Circuits 10001 ADC driver" depends on HAS_IOMEM && HAVE_CLK && REGULATOR diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 38638d4..0ba0d50 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_AD799X) += ad799x.o obj-$(CONFIG_AT91_ADC) += at91_adc.o obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o obj-$(CONFIG_AXP288_ADC) += axp288_adc.o +obj-$(CONFIG_BCM_IPROC_ADC) += bcm_iproc_adc.o obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o diff --git a/drivers/iio/adc/bcm_iproc_adc.c b/drivers/iio/adc/bcm_iproc_adc.c new file mode 100644 index 0000000..6117db7 --- /dev/null +++ b/drivers/iio/adc/bcm_iproc_adc.c @@ -0,0 +1,556 @@ +/* + * Copyright 2016 Broadcom + * + * 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 (the "GPL"). + * + * 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 version 2 (GPLv2) for more details. + * + * You should have received a copy of the GNU General Public License + * version 2 (GPLv2) along with this source code. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/iio/iio.h> +#include <linux/iio/machine.h> +#include <linux/iio/driver.h> + +#define ADC_READ_TIMEOUT (HZ*2) + +/* Register offsets */ +#define REGCTL1 0x00 +#define REGCTL2 0x04 +#define INTERRUPT_THRES 0x08 +#define INTRPT_MASK 0x0c +#define INTRPT_STATUS 0x10 +#define ANALOG_CONTROL 0x1c +#define CONTROLLER_STATUS 0x14 +#define AUX_DATA 0x20 +#define SOFT_BYPASS_CONTROL 0x38 +#define SOFT_BYPASS_DATA 0x3C + +/* ADC Channel register offsets */ +#define ADC_CHANNEL_REGCTL1 (0x800) +#define ADC_CHANNEL_REGCTL2 (0x804) +#define ADC_CHANNEL_STATUS (0x808) +#define ADC_CHANNEL_INTERRUPT_STATUS (0x80c) +#define ADC_CHANNEL_INTERRUPT_MASK (0x810) +#define ADC_CHANNEL_DATA (0x814) +#define ADC_CHANNEL_OFFSET (0x20) +/* Masks for RegCtl2 */ +#define ADC_AUXIN_SCAN_ENA (1 << 0) +#define ADC_PWR_LDO (1 << 5) +#define ADC_PWR_ADC (1 << 4) +#define ADC_PWR_BG (1 << 3) +#define ADC_CONTROLLER_EN (1 << 17) + +/* Masks for Interrupt_Mask and Interrupt_Status reg */ +#define ADC_AUXDATA_RDY_INTR (1 << 3) +#define ADC_INTR_SHIFT 9 +#define ADC_INTR_MASK (0xFF << ADC_INTR_SHIFT) + +/* Number of time to retry a set of the interrupt mask reg */ +#define INTMASK_RETRY_ATTEMPTS 10 + +/* ANALOG_CONTROL Bit Masks */ +#define CHANNEL_SEL_SHIFT 11 +#define CHANNEL_SEL_MASK (0x7 << CHANNEL_SEL_SHIFT) + +/* ADC_CHANNEL_REGCTL1 Bit Masks */ +#define CHANNEL_ROUNDS_SHIFT 0x2 +#define CHANNEL_ROUNDS_MASK (0x3F << CHANNEL_ROUNDS_SHIFT) +#define CHANNEL_MODE_SHIFT 0x1 +#define CHANNEL_MODE_MASK (0x1 << CHANNEL_MODE_SHIFT) +#define CHANNEL_MODE_TDM (0x1) +#define CHANNEL_MODE_SNAPSHOT (0x0) +#define CHANNEL_ENABLE_SHIFT 0x0 +#define CHANNEL_ENABLE_MASK (0x1) + +#define CHANNEL_ENABLE (0x1) +#define CHANNEL_DISABLE (0x0) + +/* ADC_CHANNEL_REGCTL2 Bit Masks */ +#define CHANNEL_WATERMARK_SHIFT 0x0 +#define CHANNEL_WATERMARK_MASK (0x3F << CHANNEL_WATERMARK_SHIFT) + +#define WATER_MARK_LEVEL (0x1) + +/* ADC_CHANNEL_STATUS Bit Masks */ +#define CHANNEL_DATA_LOST_SHIFT 0x0 +#define CHANNEL_DATA_LOST_MASK (0x0 << CHANNEL_DATA_LOST_SHIFT) +#define CHANNEL_VALID_ENTERIES_SHIFT 0x1 +#define CHANNEL_VALID_ENTERIES_MASK (0xFF << CHANNEL_VALID_ENTERIES_SHIFT) +#define CHANNEL_TOTAL_ENTERIES_SHIFT 0x9 +#define CHANNEL_TOTAL_ENTERIES_MASK (0xFF << CHANNEL_TOTAL_ENTERIES_SHIFT) + +/* ADC_CHANNEL_INTERRUPT_MASK Bit Masks */ +#define CHANNEL_WTRMRK_INTR_SHIFT (0x0) +#define CHANNEL_WTRMRK_INTR_MASK (0x1 << CHANNEL_WTRMRK_INTR_SHIFT) +#define CHANNEL_FULL_INTR_SHIFT 0x1 +#define CHANNEL_FULL_INTR_MASK (0x1 << CHANNEL_FULL_INTR_SHIFT) +#define CHANNEL_EMPTY_INTR_SHIFT 0x2 +#define CHANNEL_EMPTY_INTR_MASK (0x1 << CHANNEL_EMPTY_INTR_SHIFT) + +#define WATER_MARK_INTR_ENABLE (0x1) + +#define dbg_reg(dev, priv, reg) \ +do { \ + u32 val; \ + regmap_read(priv->regmap, reg, &val); \ + dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \ +} while (0) + +struct iproc_adc_priv { + struct regmap *regmap; + struct clk *adc_clk; + struct mutex mutex; + int irqno; + int chan_val; + int chan_id; /* Channel id */ + struct completion completion; +}; + +static void iproc_adc_reg_dump(struct iio_dev *indio_dev) +{ + struct iproc_adc_priv *adc_priv; + struct device *dev = &indio_dev->dev; + + adc_priv = iio_priv(indio_dev); + + dbg_reg(dev, adc_priv, REGCTL1); + dbg_reg(dev, adc_priv, REGCTL2); + dbg_reg(dev, adc_priv, INTERRUPT_THRES); + dbg_reg(dev, adc_priv, INTRPT_MASK); + dbg_reg(dev, adc_priv, INTRPT_STATUS); + dbg_reg(dev, adc_priv, CONTROLLER_STATUS); + dbg_reg(dev, adc_priv, ANALOG_CONTROL); + dbg_reg(dev, adc_priv, AUX_DATA); + dbg_reg(dev, adc_priv, SOFT_BYPASS_CONTROL); + dbg_reg(dev, adc_priv, SOFT_BYPASS_DATA); +} + +static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data) +{ + struct iproc_adc_priv *adc_priv; + struct iio_dev *indio_dev = data; + u32 channel_intr_status = 0; + u32 intr_status = 0; + u32 intr_mask = 0; + irqreturn_t retval = IRQ_NONE; + + adc_priv = iio_priv(indio_dev); + + /* This interrupt is shared with the touchscreen driver. + * Make sure this interrupt is intended for us. + * Handle only ADC channel specific interrupts. + */ + regmap_read(adc_priv->regmap, INTRPT_STATUS, &intr_status); + regmap_read(adc_priv->regmap, INTRPT_MASK, &intr_mask); + intr_status = intr_status & intr_mask; + channel_intr_status = (intr_status & ADC_INTR_MASK) >> (ADC_INTR_SHIFT); + if (channel_intr_status) + retval = IRQ_WAKE_THREAD; + return retval; +} + +static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data) +{ + irqreturn_t retval = IRQ_NONE; + struct iproc_adc_priv *adc_priv; + struct iio_dev *indio_dev = data; + unsigned int valid_entries; + u32 intr_status = 0; + u32 intr_channels = 0; + u32 channel_status = 0; + u32 ch_intr_status = 0; + + adc_priv = iio_priv(indio_dev); + + regmap_read(adc_priv->regmap, INTRPT_STATUS, &intr_status); + dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_work(), INTSTS:%x\n", + intr_status); + + intr_channels = (intr_status & ADC_INTR_MASK) >> (ADC_INTR_SHIFT); + if (intr_channels) { + regmap_read(adc_priv->regmap, + ADC_CHANNEL_INTERRUPT_STATUS + + ADC_CHANNEL_OFFSET * adc_priv->chan_id, + &ch_intr_status); + if (ch_intr_status & CHANNEL_WTRMRK_INTR_MASK) { + regmap_write(adc_priv->regmap, + ADC_CHANNEL_INTERRUPT_MASK + + ADC_CHANNEL_OFFSET * + adc_priv->chan_id, + (ch_intr_status & + ~(CHANNEL_WTRMRK_INTR_MASK))); + + regmap_read(adc_priv->regmap, + ADC_CHANNEL_STATUS + + ADC_CHANNEL_OFFSET * adc_priv->chan_id, + &channel_status); + + valid_entries = ((channel_status & + CHANNEL_VALID_ENTERIES_MASK) >> + CHANNEL_VALID_ENTERIES_SHIFT); + if (valid_entries >= 1) { + regmap_read(adc_priv->regmap, + ADC_CHANNEL_DATA + + ADC_CHANNEL_OFFSET * + adc_priv->chan_id, + &adc_priv->chan_val); + complete(&adc_priv->completion); + } else { + dev_err(&indio_dev->dev, + "No data rcvd on channel %d\n", + adc_priv->chan_id); + } + } + regmap_write(adc_priv->regmap, + ADC_CHANNEL_INTERRUPT_STATUS + + ADC_CHANNEL_OFFSET * adc_priv->chan_id, + ch_intr_status); + regmap_write(adc_priv->regmap, INTRPT_STATUS, intr_channels); + retval = IRQ_HANDLED; + } + return retval; +} + +int bcm_iproc_adc_read_raw(struct iio_dev *indio_dev, + int channel, + u16 *p_adc_data16) +{ + int read_len = 0; + u32 val; + u32 mask; + u32 val_check; + int failed_cnt = 0; + struct iproc_adc_priv *adc_priv; + + adc_priv = iio_priv(indio_dev); + + mutex_lock(&adc_priv->mutex); + + /* After a read is complete the ADC interrupts will be disabled so + * we can assume this section of code is save from interrupts. + */ + adc_priv->chan_val = -1; + adc_priv->chan_id = channel; + + reinit_completion(&adc_priv->completion); + /* Clear any pending interrupt */ + regmap_update_bits(adc_priv->regmap, INTRPT_STATUS, ADC_INTR_MASK | + ADC_AUXDATA_RDY_INTR, ((CHANNEL_DISABLE << channel)<< + ADC_INTR_SHIFT) | ADC_AUXDATA_RDY_INTR); + + /* Configure channel for snapshot mode and enable */ + val = (BIT(CHANNEL_ROUNDS_SHIFT) | + (CHANNEL_MODE_SNAPSHOT << CHANNEL_MODE_SHIFT) | + (CHANNEL_ENABLE << CHANNEL_ENABLE_SHIFT)); + + mask = CHANNEL_ROUNDS_MASK | CHANNEL_MODE_MASK | CHANNEL_ENABLE_MASK; + regmap_update_bits(adc_priv->regmap, (ADC_CHANNEL_REGCTL1 + + ADC_CHANNEL_OFFSET * channel), + mask, val); + + /* Set the Watermark for a channel */ + regmap_update_bits(adc_priv->regmap, (ADC_CHANNEL_REGCTL2 + + ADC_CHANNEL_OFFSET * channel), + CHANNEL_WATERMARK_MASK, WATER_MARK_LEVEL); + + /* Enable water mark interrupt */ + regmap_update_bits(adc_priv->regmap, (ADC_CHANNEL_INTERRUPT_MASK + + ADC_CHANNEL_OFFSET * channel), + CHANNEL_WTRMRK_INTR_MASK, WATER_MARK_INTR_ENABLE); + regmap_read(adc_priv->regmap, INTRPT_MASK, &val); + + /* Enable ADC interrupt for a channel */ + val |= (BIT(channel) << ADC_INTR_SHIFT); + regmap_write(adc_priv->regmap, INTRPT_MASK, val); + + /* There seems to be a very rare issue where writing to this register + * does not take effect. To work around the issue we will try multiple + * writes. In total we will spend about 10*10 = 100 us attempting this. + * Testing has shown that this may loop a few time, but we have never + * hit the full count. + */ + regmap_read(adc_priv->regmap, INTRPT_MASK, &val_check); + while (val_check != val) { + failed_cnt++; + + if (failed_cnt > INTMASK_RETRY_ATTEMPTS) + break; + + udelay(10); + regmap_update_bits(adc_priv->regmap, INTRPT_MASK, + ADC_INTR_MASK, + ((CHANNEL_ENABLE << channel) << + ADC_INTR_SHIFT)); + + regmap_read(adc_priv->regmap, INTRPT_MASK, &val_check); + } + + if (failed_cnt) { + dev_dbg(&indio_dev->dev, + "IntMask failed (%d times)", failed_cnt); + if (failed_cnt > INTMASK_RETRY_ATTEMPTS) { + dev_err(&indio_dev->dev, + "IntMask set failed. Read will likely fail."); + read_len = -EIO; + goto adc_err; + }; + } + regmap_read(adc_priv->regmap, INTRPT_MASK, &val_check); + + if (wait_for_completion_timeout(&adc_priv->completion, + ADC_READ_TIMEOUT) > 0) { + + /* Only the lower 16 bits are relevant */ + *p_adc_data16 = adc_priv->chan_val & 0xFFFF; + read_len = sizeof(*p_adc_data16); + + } else { + /* We never got the interrupt, something went wrong. + * Perhaps the interrupt may still be coming, we do not want + * that now. Lets disable the ADC interrupt, and clear the + * status to put it back in to normal state. + */ + read_len = -ETIMEDOUT; + goto adc_err; + } + mutex_unlock(&adc_priv->mutex); + return read_len; + +adc_err: + regmap_update_bits(adc_priv->regmap, INTRPT_MASK, + ADC_INTR_MASK, + ((CHANNEL_DISABLE << channel) << ADC_INTR_SHIFT)); + + regmap_update_bits(adc_priv->regmap, INTRPT_STATUS, + ADC_INTR_MASK, ((CHANNEL_DISABLE << channel) + << ADC_INTR_SHIFT)); + + dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n"); + iproc_adc_reg_dump(indio_dev); + mutex_unlock(&adc_priv->mutex); + return read_len; +} + + +static void iproc_adc_enable(struct iio_dev *indio_dev) +{ + u32 val; + u32 channel_id; + struct iproc_adc_priv *adc_priv; + + adc_priv = iio_priv(indio_dev); + + /* Set i_amux = 3b'000, select channel 0 */ + regmap_update_bits(adc_priv->regmap, ANALOG_CONTROL, + CHANNEL_SEL_MASK, 0); + adc_priv->chan_val = -1; + + /* PWR up LDO, ADC, and Band Gap (0 to enable) + * Also enable ADC controller (set high) + */ + regmap_read(adc_priv->regmap, REGCTL2, &val); + + val &= ~(ADC_PWR_LDO | ADC_PWR_ADC | ADC_PWR_BG); + + regmap_write(adc_priv->regmap, REGCTL2, val); + + regmap_read(adc_priv->regmap, REGCTL2, &val); + val |= ADC_CONTROLLER_EN; + regmap_write(adc_priv->regmap, REGCTL2, val); + for (channel_id = 0; channel_id < indio_dev->num_channels; + channel_id++) { + regmap_write(adc_priv->regmap, ADC_CHANNEL_INTERRUPT_MASK + + ADC_CHANNEL_OFFSET * channel_id, 0); + regmap_write(adc_priv->regmap, ADC_CHANNEL_INTERRUPT_STATUS + + ADC_CHANNEL_OFFSET * channel_id, 0); + } +} + + +static int iproc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long mask) +{ + u16 adc_data16; + int err; + + dev_dbg(&indio_dev->dev, "iproc_read_raw: channel no-%d\n", + chan->channel); + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + err = bcm_iproc_adc_read_raw(indio_dev, + chan->channel, + &adc_data16); + if (err < 0) + return err; + + *val = adc_data16; + *val2 = 0; + return IIO_VAL_INT; +} + +static const struct iio_info iproc_adc_iio_info = { + .read_raw = &iproc_read_raw, + .driver_module = THIS_MODULE, +}; + +#define ADC_CHANNEL(_index, _id) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = _index, \ + .scan_index = _index, \ + .address = _index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .datasheet_name = _id, \ + .scan_type.sign = 'u', \ + .scan_type.realbits = 10, \ + .scan_type.storagebits = 16, \ +} + +static const struct iio_chan_spec iproc_adc_iio_channels[] = { + ADC_CHANNEL(0, "adc0"), + ADC_CHANNEL(1, "adc1"), + ADC_CHANNEL(2, "adc2"), + ADC_CHANNEL(3, "adc3"), + ADC_CHANNEL(4, "adc4"), + ADC_CHANNEL(5, "adc5"), + ADC_CHANNEL(6, "adc6"), + ADC_CHANNEL(7, "adc7"), +}; + +static int iproc_adc_probe(struct platform_device *pdev) +{ + struct iproc_adc_priv *adc_priv; + struct iio_dev *indio_dev = NULL; + int ret; + + indio_dev = iio_device_alloc(sizeof(struct iproc_adc_priv)); + if (!indio_dev) { + dev_err(&pdev->dev, "failed to allocate iio device\n"); + return -ENOMEM; + } + adc_priv = iio_priv(indio_dev); + platform_set_drvdata(pdev, indio_dev); + + mutex_init(&adc_priv->mutex); + + init_completion(&adc_priv->completion); + + adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, + "adc-syscon"); + if (IS_ERR(adc_priv->regmap)) { + dev_err(&pdev->dev, "failed to get handle for tsc syscon\n"); + ret = PTR_ERR(adc_priv->regmap); + goto err_iio; + } + + adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk"); + if (IS_ERR(adc_priv->adc_clk)) { + dev_err(&pdev->dev, + "%s Failed getting clock tsc_clk\n", __func__); + ret = PTR_ERR(adc_priv->adc_clk); + goto err_iio; + } + + /* get interrupt */ + adc_priv->irqno = platform_get_irq(pdev, 0); + if (adc_priv->irqno <= 0) { + dev_err(&pdev->dev, "%s platform_get_irq failed\n", __func__); + ret = -ENODEV; + goto err_iio; + } + + regmap_update_bits(adc_priv->regmap, REGCTL2, ADC_AUXIN_SCAN_ENA, 0); + + ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno, + iproc_adc_interrupt_thread, + iproc_adc_interrupt_handler, + IRQF_SHARED, "iproc-adc", indio_dev); + if (ret) { + dev_err(&pdev->dev, "request_irq error %d\n", ret); + goto err_iio; + } + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->dev.parent = &pdev->dev; + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->info = &iproc_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = iproc_adc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret); + goto err_iio; + } + + /* Enable clock */ + ret = clk_prepare_enable(adc_priv->adc_clk); + if (ret) { + dev_err(&pdev->dev, + "%s clk_prepare_enable failed %d\n", __func__, ret); + goto err_iio_dev; + } + iproc_adc_enable(indio_dev); + return 0; +err_iio_dev: + iio_device_unregister(indio_dev); +err_iio: + iio_device_free(indio_dev); + return ret; +} + +static int iproc_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct iproc_adc_priv *adc_priv = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + clk_disable_unprepare(adc_priv->adc_clk); + iio_device_free(indio_dev); + platform_set_drvdata(pdev, NULL); + return 0; +} + +static const struct of_device_id iproc_adc_of_match[] = { + {.compatible = "brcm,iproc-static-adc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, iproc_adc_of_match); + +static struct platform_driver iproc_adc_driver = { + .probe = iproc_adc_probe, + .remove = iproc_adc_remove, + .driver = { + .name = "iproc-static-adc", + .of_match_table = of_match_ptr(iproc_adc_of_match), + }, +}; + + +module_platform_driver(iproc_adc_driver); + +MODULE_DESCRIPTION("IPROC ADC driver"); +MODULE_AUTHOR("Broadcom"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html