Re: [PATCH 2/3] iio: adc: mxs-lradc: Add support for adc driver
From: Jonathan Cameron <jic23@kernel.org>
Date: 2016-05-29 16:47:03
Also in:
linux-iio, lkml
On 28/05/16 18:49, Ksenija Stanojević wrote:
On Sun, May 1, 2016 at 6:38 PM, Jonathan Cameron [off-list ref] wrote:quoted
On 29/04/16 12:48, Ksenija Stanojevic wrote:quoted
Add mxs-lradc adc driver. Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>Mostly looking good. A few nitpicks and suggestions inline. Jonathanquoted
--- drivers/iio/adc/Kconfig | 37 +- drivers/iio/adc/Makefile | 1 + drivers/iio/adc/mxs-lradc-adc.c | 832 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 858 insertions(+), 12 deletions(-) create mode 100644 drivers/iio/adc/mxs-lradc-adc.cdiff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 82c718c..50847b8 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig@@ -233,6 +233,19 @@ config IMX7D_ADC This driver can also be built as a module. If so, the module will be called imx7d_adc. +config MXS_LRADC_ADC + tristate "Freescale i.MX23/i.MX28 LRADC ADC" + depends on MFD_MXS_LRADC + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for the ADC functions of the + i.MX23/i.MX28 LRADC. This includes general-purpose ADC readings, + battery voltage measurement, and die temperature measurement. + + This driver can also be built as a module. If so, the module will be + called mxs-lradc-adc. + config LP8788_ADC tristate "LP8788 ADC driver" depends on MFD_LP8788@@ -306,18 +319,18 @@ config MEN_Z188_ADC called men_z188_adc. config MXS_LRADC - tristate "Freescale i.MX23/i.MX28 LRADC" - depends on (ARCH_MXS || COMPILE_TEST) && HAS_IOMEM - depends on INPUT - select STMP_DEVICE - select IIO_BUFFER - select IIO_TRIGGERED_BUFFER - help - Say yes here to build support for i.MX23/i.MX28 LRADC convertor - built into these chips. - - To compile this driver as a module, choose M here: the - module will be called mxs-lradc. + tristate "Freescale i.MX23/i.MX28 LRADC" + depends on (ARCH_MXS || COMPILE_TEST) && HAS_IOMEM + depends on INPUT + select STMP_DEVICE + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for i.MX23/i.MX28 LRADC convertor + built into these chips. + + To compile this driver as a module, choose M here: the + module will be called mxs-lradc. config NAU7802 tristate "Nuvoton NAU7802 ADC driver"diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 0cb7921..ca7d6aa 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile@@ -31,6 +31,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o +obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o obj-$(CONFIG_NAU7802) += nau7802.o obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.odiff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c new file mode 100644 index 0000000..793c369 --- /dev/null +++ b/drivers/iio/adc/mxs-lradc-adc.c@@ -0,0 +1,832 @@ +/* + * Freescale MXS LRADC ADC driver + * + * Copyright (c) 2012 DENX Software Engineering, GmbH. + * Marek Vasut <marex@denx.de>You should probably add your own copyright as you are making substantial improvements!quoted
+ * + * 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. + */ + +#include <linux/mfd/mxs-lradc.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/sysfs.h> + +/* + * Make this runtime configurable if necessary. Currently, if the buffered mode + * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before + * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000) + * seconds. The result is that the samples arrive every 500mS. + */ +#define LRADC_DELAY_TIMER_PER 200 +#define LRADC_DELAY_TIMER_LOOP 5 + +#define VREF_MV_BASE 1850 + +static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = { + [IMX23_LRADC] = { + VREF_MV_BASE, /* CH0 */ + VREF_MV_BASE, /* CH1 */ + VREF_MV_BASE, /* CH2 */ + VREF_MV_BASE, /* CH3 */ + VREF_MV_BASE, /* CH4 */ + VREF_MV_BASE, /* CH5 */ + VREF_MV_BASE * 2, /* CH6 VDDIO */ + VREF_MV_BASE * 4, /* CH7 VBATT */ + VREF_MV_BASE, /* CH8 Temp sense 0 */ + VREF_MV_BASE, /* CH9 Temp sense 1 */ + VREF_MV_BASE, /* CH10 */ + VREF_MV_BASE, /* CH11 */ + VREF_MV_BASE, /* CH12 USB_DP */ + VREF_MV_BASE, /* CH13 USB_DN */ + VREF_MV_BASE, /* CH14 VBG */ + VREF_MV_BASE * 4, /* CH15 VDD5V */ + }, + [IMX28_LRADC] = { + VREF_MV_BASE, /* CH0 */ + VREF_MV_BASE, /* CH1 */ + VREF_MV_BASE, /* CH2 */ + VREF_MV_BASE, /* CH3 */ + VREF_MV_BASE, /* CH4 */ + VREF_MV_BASE, /* CH5 */ + VREF_MV_BASE, /* CH6 */ + VREF_MV_BASE * 4, /* CH7 VBATT */ + VREF_MV_BASE, /* CH8 Temp sense 0 */ + VREF_MV_BASE, /* CH9 Temp sense 1 */ + VREF_MV_BASE * 2, /* CH10 VDDIO */ + VREF_MV_BASE, /* CH11 VTH */ + VREF_MV_BASE * 2, /* CH12 VDDA */ + VREF_MV_BASE, /* CH13 VDDD */ + VREF_MV_BASE, /* CH14 VBG */ + VREF_MV_BASE * 4, /* CH15 VDD5V */ + }, +}; + +enum mxs_lradc_divbytwo { + MXS_LRADC_DIV_DISABLED = 0, + MXS_LRADC_DIV_ENABLED, +}; + +struct mxs_lradc_scale { + unsigned int integer; + unsigned int nano; +}; + +struct mxs_lradc_adc { + struct mxs_lradc *lradc; + struct device *dev; + + u32 *buffer; + struct iio_trigger *trig; + struct mutex lock; + struct completion completion; + + const u32 *vref_mv; + struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2]; + unsigned long is_divided; +}; + +/* + * Raw I/O operations + */ +static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan, + int *val) +{ + struct mxs_lradc_adc *adc = iio_priv(iio_dev); + struct mxs_lradc *lradc = adc->lradc; + int ret; + + /* + * See if there is no buffered operation in progress. If there is simply + * bail out. This can be improved to support both buffered and raw IO at + * the same time, yet the code becomes horribly complicated. Therefore I + * applied KISS principle here.This is true in lots of devices! Hence we often have a similar check.quoted
+ */ + ret = mutex_trylock(&adc->lock); + if (!ret) + return -EBUSY;We have standard core infrastructure for this now that should do the trick. iio_device_claim_direct_mode() etc.quoted
+ + reinit_completion(&adc->completion); + + /* + * No buffered operation in progress, map the channel and trigger it. + * Virtual channel 0 is always used here as the others are always not + * used if doing raw sampling. + */ + if (lradc->soc == IMX28_LRADC) + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), + LRADC_CTRL1); + mxs_lradc_reg_clear(lradc, 0x1, LRADC_CTRL0); + + /* Enable / disable the divider per requirement */ + if (test_bit(chan, &adc->is_divided)) + mxs_lradc_reg_set(lradc, + 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, + LRADC_CTRL2); + else + mxs_lradc_reg_clear(lradc, + 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, + LRADC_CTRL2); + + /* Clean the slot's previous content, then set new one. */ + mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0), + LRADC_CTRL4); + mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4); + + mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0)); + + /* Enable the IRQ and start sampling the channel. */ + mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1); + mxs_lradc_reg_set(lradc, BIT(0), LRADC_CTRL0); + + /* Wait for completion on the channel, 1 second max. */ + ret = wait_for_completion_killable_timeout(&adc->completion, HZ); + if (!ret) + ret = -ETIMEDOUT; + if (ret < 0) + goto err; + + /* Read the data. */ + *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK; + ret = IIO_VAL_INT; + +err: + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1); + + mutex_unlock(&adc->lock); + + return ret; +} + +static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val) +{ + int ret, min, max; + + ret = mxs_lradc_adc_read_single(iio_dev, 8, &min); + if (ret != IIO_VAL_INT) + return ret; + + ret = mxs_lradc_adc_read_single(iio_dev, 9, &max); + if (ret != IIO_VAL_INT) + return ret; + + *val = max - min; + + return IIO_VAL_INT; +} + +static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long m) +{ + struct mxs_lradc_adc *adc = iio_priv(iio_dev); + + switch (m) { + case IIO_CHAN_INFO_RAW: + if (chan->type == IIO_TEMP) + return mxs_lradc_adc_read_temp(iio_dev, val); + + return mxs_lradc_adc_read_single(iio_dev, chan->channel, val); + + case IIO_CHAN_INFO_SCALE: + if (chan->type == IIO_TEMP) { + /* From the datasheet, we have to multiply by 1.012 and + * divide by 4 + */ + *val = 0; + *val2 = 253000; + return IIO_VAL_INT_PLUS_MICRO; + } + + *val = adc->vref_mv[chan->channel]; + *val2 = chan->scan_type.realbits - + test_bit(chan->channel, &adc->is_divided);blank line here as you have done elsewhere...quoted
+ return IIO_VAL_FRACTIONAL_LOG2; + + case IIO_CHAN_INFO_OFFSET: + if (chan->type == IIO_TEMP) {standard multiline comment syntax please. Please fix this throughout. /* * The ...quoted
+ /* The calculated value from the ADC is in Kelvin, we + * want Celsius for hwmon so the offset is -273.15 + * The offset is applied before scaling so it is + * actually -213.15 * 4 / 1.012 = -1079.644268 + */ + *val = -1079; + *val2 = 644268; + + return IIO_VAL_INT_PLUS_MICRO; + } + + return -EINVAL; + + default: + break; + } + + return -EINVAL; +} + +static int mxs_lradc_adc_write_raw(struct iio_dev *iio_dev, + const struct iio_chan_spec *chan, + int val, int val2, long m) +{ + struct mxs_lradc_adc *adc = iio_priv(iio_dev); + struct mxs_lradc_scale *scale_avail = + adc->scale_avail[chan->channel]; + int ret; + + ret = mutex_trylock(&adc->lock); + if (!ret) + return -EBUSY; + + switch (m) { + case IIO_CHAN_INFO_SCALE: + ret = -EINVAL; + if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer && + val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) { + /* divider by two disabled */ + clear_bit(chan->channel, &adc->is_divided); + ret = 0; + } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer && + val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) { + /* divider by two enabled */ + set_bit(chan->channel, &adc->is_divided); + ret = 0; + } + + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&adc->lock); + + return ret; +} + +static int mxs_lradc_adc_write_raw_get_fmt(struct iio_dev *iio_dev, + const struct iio_chan_spec *chan, + long m) +{ + return IIO_VAL_INT_PLUS_NANO; +} + +static ssize_t mxs_lradc_adc_show_scale_avail_ch(struct device *dev, + struct device_attribute *attr, + char *buf, + int ch) +{ + struct iio_dev *iio = dev_to_iio_dev(dev); + struct mxs_lradc_adc *adc = iio_priv(iio); + int i, len = 0; + + for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++) + len += sprintf(buf + len, "%u.%09u ", + adc->scale_avail[ch][i].integer, + adc->scale_avail[ch][i].nano); + + len += sprintf(buf + len, "\n"); + + return len; +} +I'm unconvinced this wrapper adds anything...quoted
+static ssize_t mxs_lradc_adc_show_scale_avail(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr); + + return mxs_lradc_adc_show_scale_avail_ch(dev, attr, buf, + iio_attr->address); +} + +#define SHOW_SCALE_AVAILABLE_ATTR(ch) \ +static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \ + mxs_lradc_adc_show_scale_avail, NULL, ch) + +SHOW_SCALE_AVAILABLE_ATTR(0); +SHOW_SCALE_AVAILABLE_ATTR(1); +SHOW_SCALE_AVAILABLE_ATTR(2); +SHOW_SCALE_AVAILABLE_ATTR(3); +SHOW_SCALE_AVAILABLE_ATTR(4); +SHOW_SCALE_AVAILABLE_ATTR(5); +SHOW_SCALE_AVAILABLE_ATTR(6); +SHOW_SCALE_AVAILABLE_ATTR(7); +SHOW_SCALE_AVAILABLE_ATTR(10); +SHOW_SCALE_AVAILABLE_ATTR(11); +SHOW_SCALE_AVAILABLE_ATTR(12); +SHOW_SCALE_AVAILABLE_ATTR(13); +SHOW_SCALE_AVAILABLE_ATTR(14); +SHOW_SCALE_AVAILABLE_ATTR(15); + +static struct attribute *mxs_lradc_adc_attributes[] = { + &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr, + &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group mxs_lradc_adc_attribute_group = { + .attrs = mxs_lradc_adc_attributes, +}; + +static const struct iio_info mxs_lradc_adc_iio_info = { + .driver_module = THIS_MODULE, + .read_raw = mxs_lradc_adc_read_raw, + .write_raw = mxs_lradc_adc_write_raw, + .write_raw_get_fmt = mxs_lradc_adc_write_raw_get_fmt, + .attrs = &mxs_lradc_adc_attribute_group, +}; + +/* + * IRQ Handling + */Single line comment syntax preferred.quoted
+static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data) +{ + struct iio_dev *iio = data; + struct mxs_lradc_adc *adc = iio_priv(iio); + struct mxs_lradc *lradc = adc->lradc; + unsigned long reg = readl(lradc->base + LRADC_CTRL1); + + if (!(reg & mxs_lradc_irq_mask(lradc))) + return IRQ_NONE; + + if (iio_buffer_enabled(iio)) { + if (reg & lradc->buffer_vchans) + iio_trigger_poll(iio->trig); + } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) { + complete(&adc->completion); + } + + mxs_lradc_reg_clear(lradc, reg & mxs_lradc_irq_mask(lradc), + LRADC_CTRL1); + + return IRQ_HANDLED; +} + +/* + * Trigger handlingSingle line comment - Clearly it's kind of more of a heading but I'd rather not deal with the inevitable patch converting it to the standard single line format!quoted
+ */ +static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *iio = pf->indio_dev; + struct mxs_lradc_adc *adc = iio_priv(iio); + const u32 chan_value = LRADC_CH_ACCUMULATE | + ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); + unsigned int i, j = 0; + + for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { + adc->buffer[j] = readl(adc->lradc->base + LRADC_CH(j)); + mxs_lradc_reg_wrt(adc->lradc, chan_value, LRADC_CH(j)); + adc->buffer[j] &= LRADC_CH_VALUE_MASK; + adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP; + j++; + } + + iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp); + + iio_trigger_notify_done(iio->trig); + + return IRQ_HANDLED; +} + +static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state) +{ + struct iio_dev *iio = iio_trigger_get_drvdata(trig); + struct mxs_lradc_adc *adc = iio_priv(iio); + const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR; + + mxs_lradc_reg_wrt(adc->lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st); + + return 0; +} + +static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = { + .owner = THIS_MODULE, + .set_trigger_state = &mxs_lradc_adc_configure_trigger, +}; + +static int mxs_lradc_adc_trigger_init(struct iio_dev *iio) +{ + int ret; + struct iio_trigger *trig; + struct mxs_lradc_adc *adc = iio_priv(iio); +Could simplify things ever so slightly by using devm_iio_trigger_alloc if you were to reorder the trigger init to be before the buffer setup (which I think should be fine). Perhaps it is not worth the hassle...quoted
+ trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id); + if (!trig) + return -ENOMEM; + + trig->dev.parent = adc->dev; + iio_trigger_set_drvdata(trig, iio); + trig->ops = &mxs_lradc_adc_trigger_ops; + + ret = iio_trigger_register(trig); + if (ret) { + iio_trigger_free(trig); + return ret; + } + + adc->trig = trig; + + return 0; +} + +static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio) +{ + struct mxs_lradc_adc *adc = iio_priv(iio); + + iio_trigger_unregister(adc->trig); + iio_trigger_free(adc->trig); +} + +static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio) +{ + struct mxs_lradc_adc *adc = iio_priv(iio); + struct mxs_lradc *lradc = adc->lradc; + int ret = 0, chan, ofs = 0; + unsigned long enable = 0; + u32 ctrl4_set = 0; + u32 ctrl4_clr = 0; + u32 ctrl1_irq = 0; + const u32 chan_value = LRADC_CH_ACCUMULATE | + ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET); + const int len = bitmap_weight(iio->active_scan_mask, + LRADC_MAX_TOTAL_CHANS); + + if (!len) + return -EINVAL; + + /* + * Lock the driver so raw access can not be done during buffered + * operation. This simplifies the code a lot. + */ + ret = mutex_trylock(&adc->lock); + if (!ret) + return -EBUSY;Hmm. could this use iio_dev->mlock? That is what that particular lock is for and it has nice wrapper functions to make it clear.quoted
+ + adc->buffer = kmalloc_array(len, sizeof(*adc->buffer), GFP_KERNEL); + if (!adc->buffer) { + ret = -ENOMEM; + goto err_mem; + }I wonder if it's worth the hassel of doing this dynamically. Maybe just have a buffer that is big enough to take all possibilities as part of the adc struct?quoted
+ + if (lradc->soc == IMX28_LRADC) + mxs_lradc_reg_clear( + lradc, + lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET, + LRADC_CTRL1); + mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0); + + for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) { + ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs); + ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs); + ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs); + mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs)); + bitmap_set(&enable, ofs, 1); + ofs++; + } + + mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK | + LRADC_DELAY_KICK, LRADC_DELAY(0)); + mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4); + mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4); + mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1); + mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET, + LRADC_DELAY(0)); + + return 0; + +err_mem: + mutex_unlock(&adc->lock); + return ret; +} + +static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio) +{ + struct mxs_lradc_adc *adc = iio_priv(iio); + struct mxs_lradc *lradc = adc->lradc; + + mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK | + LRADC_DELAY_KICK, LRADC_DELAY(0)); + + mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0); + if (lradc->soc == IMX28_LRADC) + mxs_lradc_reg_clear( + lradc, + lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET, + LRADC_CTRL1); + + kfree(adc->buffer); + mutex_unlock(&adc->lock); + + return 0; +} + +static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio, + const unsigned long *mask) +{ + struct mxs_lradc_adc *adc = iio_priv(iio); + struct mxs_lradc *lradc = adc->lradc; + const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS); + int rsvd_chans = 0; + unsigned long rsvd_mask = 0; + + if (lradc->use_touchbutton) + rsvd_mask |= CHAN_MASK_TOUCHBUTTON; + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE) + rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE; + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE) + rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE; + + if (lradc->use_touchbutton) + rsvd_chans++; + if (lradc->use_touchscreen) + rsvd_chans += 2; + + /* Test for attempts to map channels with special mode of operation. */ + if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS)) + return false; + + /* Test for attempts to map more channels then available slots. */ + if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS) + return false; + + return true; +} + +static const struct iio_buffer_setup_ops mxs_lradc_adc_buffer_ops = { + .preenable = &mxs_lradc_adc_buffer_preenable, + .postenable = &iio_triggered_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, + .postdisable = &mxs_lradc_adc_buffer_postdisable, + .validate_scan_mask = &mxs_lradc_adc_validate_scan_mask, +}; + +/* + * Driver initialization + */ + +#define MXS_ADC_CHAN(idx, chan_type, name) { \ + .type = (chan_type), \ + .indexed = 1, \ + .scan_index = (idx), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .channel = (idx), \ + .address = (idx), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = LRADC_RESOLUTION, \ + .storagebits = 32, \ + }, \ + .datasheet_name = (name), \ +} + +static const struct iio_chan_spec mx23_lradc_chan_spec[] = { + MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"), + MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"), + MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"), + MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"), + MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"), + MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"), + MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"), + MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"), + /* Combined Temperature sensors */ + { + .type = IIO_TEMP, + .indexed = 1, + .scan_index = 8, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE), + .channel = 8, + .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,}, + .datasheet_name = "TEMP_DIE", + }, + /* Hidden channel to keep indexes */ + { + .type = IIO_TEMP, + .indexed = 1, + .scan_index = -1, + .channel = 9, + }, + MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL), + MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL), + MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"), + MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"), + MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"), + MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"), +}; + +static const struct iio_chan_spec mx28_lradc_chan_spec[] = { + MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"), + MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"), + MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"), + MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"), + MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"), + MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"), + MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"), + MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"), + /* Combined Temperature sensors */ + { + .type = IIO_TEMP, + .indexed = 1, + .scan_index = 8, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE), + .channel = 8, + .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,}, + .datasheet_name = "TEMP_DIE", + }, + /* Hidden channel to keep indexes */ + { + .type = IIO_TEMP, + .indexed = 1, + .scan_index = -1, + .channel = 9, + }, + MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"), + MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"), + MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"), + MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"), + MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"), + MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"), +}; + +static void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc) +{ + struct mxs_lradc *lradc = adc->lradc; + + /* The ADC always uses DELAY CHANNEL 0. */ + const u32 adc_cfg = + (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) | + (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET); + + /* Configure DELAY CHANNEL 0 for generic ADC sampling. */ + mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0)); + + /* Start internal temperature sensing. */We start internal temperature sensing, do we ever want to stop it?According to manual[1] there is no need to: To use the internal die temperature sensor, HW_LRADC_CTRL2_TEMPSENSE_PWD should be cleared. (This bit can be left cleared after power up. There is no need to toggle it on and off.)
Fair enough - perhaps a note here to make that clear to future readers?
quoted
quoted
+ mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2); +} + +static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc) +{ + mxs_lradc_reg_wrt(adc->lradc, 0, LRADC_DELAY(0)); +} + +static int mxs_lradc_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mxs_lradc *lradc = dev_get_platdata(dev); + struct mxs_lradc_adc *adc; + struct iio_dev *iio; + int ret, i, s; + u64 scale_uv; + + /* Allocate the IIO device. */ + iio = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!iio) { + dev_err(dev, "Failed to allocate IIO device\n"); + return -ENOMEM; + } + + adc = iio_priv(iio); + adc->lradc = lradc; + adc->dev = dev; + + init_completion(&adc->completion); + mutex_init(&adc->lock); + + for (i = 0; i < lradc->irq_count; i++) { + ret = devm_request_irq(dev, lradc->irq[i], + mxs_lradc_adc_handle_irq, + IRQF_SHARED, lradc->irq_name[i], iio); + if (ret) + return ret;This seems to be getting a whole load of irq's whether or not they are actually going to be used by the ADC? Aren't some of these going to be typically used by the touchscreen?quoted
+ } + + platform_set_drvdata(pdev, iio); + + iio->name = pdev->name; + iio->dev.parent = dev; + iio->dev.of_node = dev->parent->of_node; + iio->info = &mxs_lradc_adc_iio_info; + iio->modes = INDIO_DIRECT_MODE; + iio->masklength = LRADC_MAX_TOTAL_CHANS; + + if (lradc->soc == IMX23_LRADC) { + iio->channels = mx23_lradc_chan_spec; + iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec); + } else { + iio->channels = mx28_lradc_chan_spec; + iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec); + } + + ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time, + &mxs_lradc_adc_trigger_handler, + &mxs_lradc_adc_buffer_ops); + if (ret) + return ret; + + ret = mxs_lradc_adc_trigger_init(iio); + if (ret) + goto err_trig; + + adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc]; + + /* Populate available ADC input ranges */ + for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) { + for (s = 0; s < ARRAY_SIZE(adc->scale_avail[i]); s++) { + /* + * [s=0] = optional divider by two disabled (default) + * [s=1] = optional divider by two enabled + * + * The scale is calculated by doing: + * Vref >> (realbits - s) + * which multiplies by two on the second component + * of the array. + */ + scale_uv = ((u64)adc->vref_mv[i] * 100000000) >> + (LRADC_RESOLUTION - s); + adc->scale_avail[i][s].nano = + do_div(scale_uv, 100000000) * 10; + adc->scale_avail[i][s].integer = scale_uv; + } + } + + /* Configure the hardware. */ + mxs_lradc_adc_hw_init(adc); + + /* Register IIO device. */ + ret = iio_device_register(iio); + if (ret) { + dev_err(dev, "Failed to register IIO device\n"); + goto err_dev; + } + + return 0; + +err_dev: + mxs_lradc_adc_hw_stop(adc); + mxs_lradc_adc_trigger_remove(iio); +err_trig: + iio_triggered_buffer_cleanup(iio); + return ret; +} + +static int mxs_lradc_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *iio = platform_get_drvdata(pdev); + struct mxs_lradc_adc *adc = iio_priv(iio); + + iio_device_unregister(iio); + mxs_lradc_adc_hw_stop(adc); + mxs_lradc_adc_trigger_remove(iio); + iio_triggered_buffer_cleanup(iio); + + return 0; +} + +static struct platform_driver mxs_lradc_adc_driver = { + .driver = { + .name = DRIVER_NAME_ADC, + }, + .probe = mxs_lradc_adc_probe, + .remove = mxs_lradc_adc_remove, +}; + +module_platform_driver(mxs_lradc_adc_driver); + +MODULE_AUTHOR("Marek Vasut [off-list ref]"); +MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRIVER_NAME_ADC); +Bonus blank line at end of file...quoted
+[1] http://cache.freescale.com/files/dsp/doc/ref_manual/MCIMX28RM.pdf
-- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html