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439 lines
11 KiB
439 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2014-2015 Imagination Technologies Ltd. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/err.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/platform_device.h> |
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#include <linux/regulator/consumer.h> |
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#include <linux/slab.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include <linux/iio/trigger.h> |
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#include <linux/iio/trigger_consumer.h> |
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#include <linux/iio/triggered_buffer.h> |
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/* Registers */ |
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#define CC10001_ADC_CONFIG 0x00 |
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#define CC10001_ADC_START_CONV BIT(4) |
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#define CC10001_ADC_MODE_SINGLE_CONV BIT(5) |
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#define CC10001_ADC_DDATA_OUT 0x04 |
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#define CC10001_ADC_EOC 0x08 |
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#define CC10001_ADC_EOC_SET BIT(0) |
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#define CC10001_ADC_CHSEL_SAMPLED 0x0c |
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#define CC10001_ADC_POWER_DOWN 0x10 |
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#define CC10001_ADC_POWER_DOWN_SET BIT(0) |
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#define CC10001_ADC_DEBUG 0x14 |
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#define CC10001_ADC_DATA_COUNT 0x20 |
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#define CC10001_ADC_DATA_MASK GENMASK(9, 0) |
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#define CC10001_ADC_NUM_CHANNELS 8 |
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#define CC10001_ADC_CH_MASK GENMASK(2, 0) |
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#define CC10001_INVALID_SAMPLED 0xffff |
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#define CC10001_MAX_POLL_COUNT 20 |
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/* |
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* As per device specification, wait six clock cycles after power-up to |
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* activate START. Since adding two more clock cycles delay does not |
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* impact the performance too much, we are adding two additional cycles delay |
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* intentionally here. |
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*/ |
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#define CC10001_WAIT_CYCLES 8 |
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struct cc10001_adc_device { |
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void __iomem *reg_base; |
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struct clk *adc_clk; |
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struct regulator *reg; |
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u16 *buf; |
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bool shared; |
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struct mutex lock; |
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unsigned int start_delay_ns; |
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unsigned int eoc_delay_ns; |
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}; |
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static inline void cc10001_adc_write_reg(struct cc10001_adc_device *adc_dev, |
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u32 reg, u32 val) |
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{ |
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writel(val, adc_dev->reg_base + reg); |
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} |
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static inline u32 cc10001_adc_read_reg(struct cc10001_adc_device *adc_dev, |
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u32 reg) |
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{ |
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return readl(adc_dev->reg_base + reg); |
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} |
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static void cc10001_adc_power_up(struct cc10001_adc_device *adc_dev) |
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{ |
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cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_DOWN, 0); |
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ndelay(adc_dev->start_delay_ns); |
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} |
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static void cc10001_adc_power_down(struct cc10001_adc_device *adc_dev) |
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{ |
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cc10001_adc_write_reg(adc_dev, CC10001_ADC_POWER_DOWN, |
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CC10001_ADC_POWER_DOWN_SET); |
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} |
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static void cc10001_adc_start(struct cc10001_adc_device *adc_dev, |
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unsigned int channel) |
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{ |
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u32 val; |
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/* Channel selection and mode of operation */ |
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val = (channel & CC10001_ADC_CH_MASK) | CC10001_ADC_MODE_SINGLE_CONV; |
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cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val); |
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udelay(1); |
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val = cc10001_adc_read_reg(adc_dev, CC10001_ADC_CONFIG); |
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val = val | CC10001_ADC_START_CONV; |
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cc10001_adc_write_reg(adc_dev, CC10001_ADC_CONFIG, val); |
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} |
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static u16 cc10001_adc_poll_done(struct iio_dev *indio_dev, |
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unsigned int channel, |
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unsigned int delay) |
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{ |
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struct cc10001_adc_device *adc_dev = iio_priv(indio_dev); |
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unsigned int poll_count = 0; |
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while (!(cc10001_adc_read_reg(adc_dev, CC10001_ADC_EOC) & |
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CC10001_ADC_EOC_SET)) { |
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ndelay(delay); |
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if (poll_count++ == CC10001_MAX_POLL_COUNT) |
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return CC10001_INVALID_SAMPLED; |
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} |
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poll_count = 0; |
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while ((cc10001_adc_read_reg(adc_dev, CC10001_ADC_CHSEL_SAMPLED) & |
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CC10001_ADC_CH_MASK) != channel) { |
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ndelay(delay); |
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if (poll_count++ == CC10001_MAX_POLL_COUNT) |
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return CC10001_INVALID_SAMPLED; |
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} |
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/* Read the 10 bit output register */ |
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return cc10001_adc_read_reg(adc_dev, CC10001_ADC_DDATA_OUT) & |
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CC10001_ADC_DATA_MASK; |
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} |
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static irqreturn_t cc10001_adc_trigger_h(int irq, void *p) |
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{ |
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struct cc10001_adc_device *adc_dev; |
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struct iio_poll_func *pf = p; |
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struct iio_dev *indio_dev; |
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unsigned int delay_ns; |
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unsigned int channel; |
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unsigned int scan_idx; |
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bool sample_invalid; |
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u16 *data; |
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int i; |
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indio_dev = pf->indio_dev; |
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adc_dev = iio_priv(indio_dev); |
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data = adc_dev->buf; |
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mutex_lock(&adc_dev->lock); |
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if (!adc_dev->shared) |
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cc10001_adc_power_up(adc_dev); |
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/* Calculate delay step for eoc and sampled data */ |
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delay_ns = adc_dev->eoc_delay_ns / CC10001_MAX_POLL_COUNT; |
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i = 0; |
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sample_invalid = false; |
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for_each_set_bit(scan_idx, indio_dev->active_scan_mask, |
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indio_dev->masklength) { |
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channel = indio_dev->channels[scan_idx].channel; |
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cc10001_adc_start(adc_dev, channel); |
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data[i] = cc10001_adc_poll_done(indio_dev, channel, delay_ns); |
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if (data[i] == CC10001_INVALID_SAMPLED) { |
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dev_warn(&indio_dev->dev, |
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"invalid sample on channel %d\n", channel); |
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sample_invalid = true; |
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goto done; |
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} |
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i++; |
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} |
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done: |
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if (!adc_dev->shared) |
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cc10001_adc_power_down(adc_dev); |
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mutex_unlock(&adc_dev->lock); |
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if (!sample_invalid) |
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iio_push_to_buffers_with_timestamp(indio_dev, data, |
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iio_get_time_ns(indio_dev)); |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static u16 cc10001_adc_read_raw_voltage(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan) |
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{ |
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struct cc10001_adc_device *adc_dev = iio_priv(indio_dev); |
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unsigned int delay_ns; |
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u16 val; |
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if (!adc_dev->shared) |
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cc10001_adc_power_up(adc_dev); |
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/* Calculate delay step for eoc and sampled data */ |
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delay_ns = adc_dev->eoc_delay_ns / CC10001_MAX_POLL_COUNT; |
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cc10001_adc_start(adc_dev, chan->channel); |
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val = cc10001_adc_poll_done(indio_dev, chan->channel, delay_ns); |
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if (!adc_dev->shared) |
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cc10001_adc_power_down(adc_dev); |
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return val; |
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} |
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static int cc10001_adc_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct cc10001_adc_device *adc_dev = iio_priv(indio_dev); |
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int ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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if (iio_buffer_enabled(indio_dev)) |
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return -EBUSY; |
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mutex_lock(&adc_dev->lock); |
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*val = cc10001_adc_read_raw_voltage(indio_dev, chan); |
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mutex_unlock(&adc_dev->lock); |
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if (*val == CC10001_INVALID_SAMPLED) |
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return -EIO; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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ret = regulator_get_voltage(adc_dev->reg); |
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if (ret < 0) |
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return ret; |
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*val = ret / 1000; |
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*val2 = chan->scan_type.realbits; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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default: |
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return -EINVAL; |
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} |
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} |
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static int cc10001_update_scan_mode(struct iio_dev *indio_dev, |
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const unsigned long *scan_mask) |
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{ |
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struct cc10001_adc_device *adc_dev = iio_priv(indio_dev); |
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kfree(adc_dev->buf); |
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adc_dev->buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL); |
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if (!adc_dev->buf) |
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return -ENOMEM; |
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return 0; |
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} |
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static const struct iio_info cc10001_adc_info = { |
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.read_raw = &cc10001_adc_read_raw, |
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.update_scan_mode = &cc10001_update_scan_mode, |
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}; |
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static int cc10001_adc_channel_init(struct iio_dev *indio_dev, |
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unsigned long channel_map) |
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{ |
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struct iio_chan_spec *chan_array, *timestamp; |
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unsigned int bit, idx = 0; |
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indio_dev->num_channels = bitmap_weight(&channel_map, |
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CC10001_ADC_NUM_CHANNELS) + 1; |
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chan_array = devm_kcalloc(&indio_dev->dev, indio_dev->num_channels, |
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sizeof(struct iio_chan_spec), |
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GFP_KERNEL); |
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if (!chan_array) |
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return -ENOMEM; |
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for_each_set_bit(bit, &channel_map, CC10001_ADC_NUM_CHANNELS) { |
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struct iio_chan_spec *chan = &chan_array[idx]; |
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chan->type = IIO_VOLTAGE; |
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chan->indexed = 1; |
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chan->channel = bit; |
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chan->scan_index = idx; |
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chan->scan_type.sign = 'u'; |
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chan->scan_type.realbits = 10; |
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chan->scan_type.storagebits = 16; |
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chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE); |
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chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); |
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idx++; |
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} |
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timestamp = &chan_array[idx]; |
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timestamp->type = IIO_TIMESTAMP; |
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timestamp->channel = -1; |
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timestamp->scan_index = idx; |
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timestamp->scan_type.sign = 's'; |
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timestamp->scan_type.realbits = 64; |
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timestamp->scan_type.storagebits = 64; |
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indio_dev->channels = chan_array; |
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return 0; |
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} |
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static int cc10001_adc_probe(struct platform_device *pdev) |
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{ |
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struct device_node *node = pdev->dev.of_node; |
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struct cc10001_adc_device *adc_dev; |
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unsigned long adc_clk_rate; |
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struct iio_dev *indio_dev; |
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unsigned long channel_map; |
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int ret; |
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indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev)); |
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if (indio_dev == NULL) |
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return -ENOMEM; |
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adc_dev = iio_priv(indio_dev); |
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channel_map = GENMASK(CC10001_ADC_NUM_CHANNELS - 1, 0); |
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if (!of_property_read_u32(node, "adc-reserved-channels", &ret)) { |
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adc_dev->shared = true; |
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channel_map &= ~ret; |
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} |
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adc_dev->reg = devm_regulator_get(&pdev->dev, "vref"); |
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if (IS_ERR(adc_dev->reg)) |
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return PTR_ERR(adc_dev->reg); |
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ret = regulator_enable(adc_dev->reg); |
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if (ret) |
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return ret; |
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indio_dev->name = dev_name(&pdev->dev); |
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indio_dev->info = &cc10001_adc_info; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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adc_dev->reg_base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(adc_dev->reg_base)) { |
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ret = PTR_ERR(adc_dev->reg_base); |
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goto err_disable_reg; |
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} |
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adc_dev->adc_clk = devm_clk_get(&pdev->dev, "adc"); |
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if (IS_ERR(adc_dev->adc_clk)) { |
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dev_err(&pdev->dev, "failed to get the clock\n"); |
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ret = PTR_ERR(adc_dev->adc_clk); |
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goto err_disable_reg; |
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} |
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ret = clk_prepare_enable(adc_dev->adc_clk); |
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if (ret) { |
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dev_err(&pdev->dev, "failed to enable the clock\n"); |
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goto err_disable_reg; |
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} |
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adc_clk_rate = clk_get_rate(adc_dev->adc_clk); |
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if (!adc_clk_rate) { |
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ret = -EINVAL; |
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dev_err(&pdev->dev, "null clock rate!\n"); |
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goto err_disable_clk; |
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} |
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adc_dev->eoc_delay_ns = NSEC_PER_SEC / adc_clk_rate; |
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adc_dev->start_delay_ns = adc_dev->eoc_delay_ns * CC10001_WAIT_CYCLES; |
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/* |
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* There is only one register to power-up/power-down the AUX ADC. |
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* If the ADC is shared among multiple CPUs, always power it up here. |
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* If the ADC is used only by the MIPS, power-up/power-down at runtime. |
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*/ |
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if (adc_dev->shared) |
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cc10001_adc_power_up(adc_dev); |
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/* Setup the ADC channels available on the device */ |
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ret = cc10001_adc_channel_init(indio_dev, channel_map); |
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if (ret < 0) |
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goto err_disable_clk; |
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mutex_init(&adc_dev->lock); |
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ret = iio_triggered_buffer_setup(indio_dev, NULL, |
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&cc10001_adc_trigger_h, NULL); |
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if (ret < 0) |
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goto err_disable_clk; |
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ret = iio_device_register(indio_dev); |
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if (ret < 0) |
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goto err_cleanup_buffer; |
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platform_set_drvdata(pdev, indio_dev); |
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return 0; |
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err_cleanup_buffer: |
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iio_triggered_buffer_cleanup(indio_dev); |
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err_disable_clk: |
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clk_disable_unprepare(adc_dev->adc_clk); |
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err_disable_reg: |
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regulator_disable(adc_dev->reg); |
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return ret; |
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} |
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static int cc10001_adc_remove(struct platform_device *pdev) |
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{ |
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struct iio_dev *indio_dev = platform_get_drvdata(pdev); |
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struct cc10001_adc_device *adc_dev = iio_priv(indio_dev); |
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cc10001_adc_power_down(adc_dev); |
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iio_device_unregister(indio_dev); |
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iio_triggered_buffer_cleanup(indio_dev); |
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clk_disable_unprepare(adc_dev->adc_clk); |
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regulator_disable(adc_dev->reg); |
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return 0; |
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} |
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static const struct of_device_id cc10001_adc_dt_ids[] = { |
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{ .compatible = "cosmic,10001-adc", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, cc10001_adc_dt_ids); |
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static struct platform_driver cc10001_adc_driver = { |
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.driver = { |
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.name = "cc10001-adc", |
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.of_match_table = cc10001_adc_dt_ids, |
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}, |
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.probe = cc10001_adc_probe, |
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.remove = cc10001_adc_remove, |
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}; |
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module_platform_driver(cc10001_adc_driver); |
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MODULE_AUTHOR("Phani Movva <[email protected]>"); |
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MODULE_DESCRIPTION("Cosmic Circuits ADC driver"); |
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MODULE_LICENSE("GPL v2");
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