Hi Hartmut, First, thanks a lot for this feedback, I really appreciate it. On 26/05/14 00:52, Hartmut Knaack wrote:
Philippe Reynes schrieb:This driver add partial support of the maxim 1027/1029/1031. Differential mode is not supported. It was tested on armadeus apf27 board. Signed-off-by: Philippe Reynes<tremyfr@xxxxxxxx> --- .../devicetree/bindings/iio/adc/max1027-adc.txt | 21 + drivers/staging/iio/adc/Kconfig | 9 + drivers/staging/iio/adc/Makefile | 1 + drivers/staging/iio/adc/max1027.c | 553 ++++++++++++++++++++ 4 files changed, 584 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/iio/adc/max1027-adc.txt create mode 100644 drivers/staging/iio/adc/max1027.c Changelog: v2: (thanks Hartmut Knaack and Jonathan Cameron for the feedback) - really use devm_* - use demux magic - use spi_read and spi_write (instead of spi_sync) - use define for register (instead of hardcoded value) diff --git a/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt b/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt new file mode 100644 index 0000000..2e8b9f3 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/max1027-adc.txt @@ -0,0 +1,21 @@ +* Maxim 1027/1029/1031 Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "maxim,max1027" or "maxim,max1029" or "maxim,max1031" + - reg: Should contain the ADC SPI address + - interrupt-parent: the phandle for the gpio controller + - interrupts: (gpio) interrupt to which the chip is connected + +Example: +adc@0 { + compatible = "maxim,max1027"; + reg =<0>; + interrupt-parent =<&gpio5>; + interrupts =<15 IRQ_TYPE_EDGE_RISING>; + pinctrl-names = "default"; + pinctrl-0 =<&pinctrl_max1027>; + /* SPI mode = 0 */ + spi-cpol =<0>; + spi-cpha =<0>; + spi-max-frequency =<1000000>; +}; diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig index 3633298..12a78eb 100644 --- a/drivers/staging/iio/adc/Kconfig +++ b/drivers/staging/iio/adc/Kconfig @@ -112,6 +112,15 @@ config LPC32XX_ADC activate only one via device tree selection. Provides direct access via sysfs. +config MAX1027 + tristate "Maxim max1027 ADC driver" + depends on SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for Maxim SPI ADC models + max1027, max1029 and max1031. + config MXS_LRADC tristate "Freescale i.MX23/i.MX28 LRADC" depends on ARCH_MXS || COMPILE_TEST diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile index 3e9fb14..22fbd0c 100644 --- a/drivers/staging/iio/adc/Makefile +++ b/drivers/staging/iio/adc/Makefile @@ -18,5 +18,6 @@ obj-$(CONFIG_AD7816) += ad7816.o obj-$(CONFIG_AD7192) += ad7192.o obj-$(CONFIG_AD7280) += ad7280a.o obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o +obj-$(CONFIG_MAX1027) += max1027.o obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o obj-$(CONFIG_SPEAR_ADC) += spear_adc.o diff --git a/drivers/staging/iio/adc/max1027.c b/drivers/staging/iio/adc/max1027.c new file mode 100644 index 0000000..c2e5936 --- /dev/null +++ b/drivers/staging/iio/adc/max1027.c @@ -0,0 +1,553 @@ + /* + * iio/adc/max1027.c + * Copyright (C) 2014 Philippe Reynes + * + * based on linux/drivers/iio/ad7923.c + * Copyright 2011 Analog Devices Inc (from AD7923 Driver) + * Copyright 2012 CS Systemes d'Information + * + * 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. + * + * max1027.c + * + * Partial support for max1027 and similar chips. + */ + +#include<linux/kernel.h> +#include<linux/spi/spi.h> +#include<linux/module.h> +#include<linux/interrupt.h> +#include<linux/mutex.h> +#include<linux/of.h> +#include<linux/of_gpio.h> +#include<linux/platform_device.h> +#include<linux/delay.h> +#include<linux/gpio.h> + +#include<linux/iio/iio.h> +#include<linux/iio/buffer.h> +#include<linux/iio/trigger.h> +#include<linux/iio/trigger_consumer.h> +#include<linux/iio/triggered_buffer.h> + +#define MAX1027_CONV_REG 0x80 +#define MAX1027_SETUP_REG 0x40 +#define MAX1027_AVG_REG 0x20 +#define MAX1027_RST_REG 0x10 + +/* conversion register */ +#define MAX1027_TEMP 0x01 +#define MAX1027_SCAN_0_N (0x00<< 1) +#define MAX1027_SCAN_N_M (0x01<< 1) +#define MAX1027_SCAN_N (0x02<< 1) +#define MAX1027_NOSCAN (0x03<< 1) +#define MAX1027_CHAN(n) ((n)<< 3) + +/* setup register */ +#define MAX1027_UNIPOLAR 0x02 +#define MAX1027_BIPOLAR 0x03 +#define MAX1027_REF_MODE0 (0x00<< 2) +#define MAX1027_REF_MODE1 (0x01<< 2) +#define MAX1027_REF_MODE2 (0x02<< 2) +#define MAX1027_REF_MODE3 (0x03<< 2) +#define MAX1027_CKS_MODE0 (0x00<< 4) +#define MAX1027_CKS_MODE1 (0x01<< 4) +#define MAX1027_CKS_MODE2 (0x02<< 4) +#define MAX1027_CKS_MODE3 (0x03<< 4) + +/* averaging register */ +#define MAX1027_NSCAN_4 0x00 +#define MAX1027_NSCAN_8 0x01 +#define MAX1027_NSCAN_12 0x02 +#define MAX1027_NSCAN_16 0x03 +#define MAX1027_NAVG_4 (0x00<< 2) +#define MAX1027_NAVG_8 (0x01<< 2) +#define MAX1027_NAVG_12 (0x02<< 2) +#define MAX1027_NAVG_16 (0x03<< 2)According to my datasheet (revision 5) [http://datasheets.maximintegrated.com/en/ds/MAX1027-MAX1031.pdf], there is no NAVG_12, but NAVG_16 (0x02<< 2) and NAVG_32 (0x03<< 2).
My datasheet has the same value, I'll fix this mistake in v3.
+#define MAX1027_AVG_EN (0x01<< 4) + +enum max1027_id { + max1027, + max1029, + max1031, +}; + +static const struct spi_device_id max1027_id[] = { + {"max1027", max1027}, + {"max1029", max1029}, + {"max1031", max1031}, + {} +}; +MODULE_DEVICE_TABLE(spi, max1027_id); + +#ifdef CONFIG_OF +static const struct of_device_id max1027_adc_dt_ids[] = { + { .compatible = "maxim,max1027" }, + { .compatible = "maxim,max1029" }, + { .compatible = "maxim,max1031" }, + {}, +}; +MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids); +#endif + +#define MAX1027_V_CHAN(index) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .address = index, \ + .scan_index = index+1, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 10, \ + .storagebits = 16, \ + .shift = 2, \ + .endianness = IIO_BE, \ + }, \ + } + +#define MAX1027_T_CHAN(index) \ + { \ + .type = IIO_TEMP, \ + .indexed = 0, \ + .channel = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .address = index, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + .endianness = IIO_BE, \ + }, \ + } + +static const struct iio_chan_spec max1027_channels[] = { + MAX1027_T_CHAN(0), + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7) +}; + +static const struct iio_chan_spec max1029_channels[] = { + MAX1027_T_CHAN(0), + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7), + MAX1027_V_CHAN(8), + MAX1027_V_CHAN(9), + MAX1027_V_CHAN(10), + MAX1027_V_CHAN(11) +}; + +static const struct iio_chan_spec max1031_channels[] = { + MAX1027_T_CHAN(0), + MAX1027_V_CHAN(0), + MAX1027_V_CHAN(1), + MAX1027_V_CHAN(2), + MAX1027_V_CHAN(3), + MAX1027_V_CHAN(4), + MAX1027_V_CHAN(5), + MAX1027_V_CHAN(6), + MAX1027_V_CHAN(7), + MAX1027_V_CHAN(8), + MAX1027_V_CHAN(9), + MAX1027_V_CHAN(10), + MAX1027_V_CHAN(11), + MAX1027_V_CHAN(12), + MAX1027_V_CHAN(13), + MAX1027_V_CHAN(14), + MAX1027_V_CHAN(15) +}; + +static unsigned long max1027_available_scan_masks[] = { + 0x00ff, + 0x0000, +}; + +static unsigned long max1029_available_scan_masks[] = { + 0x0fff, + 0x0000, +}; + +static unsigned long max1031_available_scan_masks[] = { + 0xffff, + 0x0000, +}; + +struct max1027_chip_info { + const struct iio_chan_spec *channels; + unsigned int num_channels; + unsigned long *available_scan_masks; +}; + +static const struct max1027_chip_info max1027_chip_info_tbl[] = { + [max1027] = { + .channels = max1027_channels, + .num_channels = ARRAY_SIZE(max1027_channels), + .available_scan_masks = max1027_available_scan_masks, + }, + [max1029] = { + .channels = max1029_channels, + .num_channels = ARRAY_SIZE(max1029_channels), + .available_scan_masks = max1029_available_scan_masks, + }, + [max1031] = { + .channels = max1031_channels, + .num_channels = ARRAY_SIZE(max1031_channels), + .available_scan_masks = max1031_available_scan_masks, + }, +}; + +struct max1027_state { + struct max1027_chip_info *info; + struct spi_device *spi; + struct iio_trigger *trig; + unsigned short *buffer;Better use u16 for buffer?
Yes, fixed in v3.
+}; + +static int max1027_write_register(struct max1027_state *st, unsigned char reg) +{ + int ret; + + pr_debug("%s(st = 0x%p, reg = 0x%02x)\n", __func__, st, reg); + + ret = spi_write(st->spi, (void *)®, 1); + if (ret< 0) + pr_err("can't write register\n"); + + return ret; +}As Jonathan pointed out, better get rid of those debug wrapper functions. Otherwise, think about using typedefs like u8 for 8 bit registers.
I've remove this function (and max10247_read_value) in v3.
+ +static int max1027_read_value(struct max1027_state *st, int len) +{ + int ret; + + pr_debug("%s(st = 0x%p, len = %d)\n", __func__, st, len); + + ret = spi_read(st->spi, st->buffer, len); + if (ret< 0) + pr_err("can't read value\n"); + + return ret; +} + +static int max1027_read_single_value(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask)val2 and mask are not used.
I'll remove it in v3.
+{ + int ret; + unsigned char reg; + struct max1027_state *st = iio_priv(indio_dev); + + if (iio_buffer_enabled(indio_dev)) { + dev_warn(&indio_dev->dev, "trigger mode already enabled"); + return -EIO; + } + + /* Start acquisition on conversion register write */ + reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2; + ret = max1027_write_register(st, reg); + if (ret< 0) { + dev_err(&indio_dev->dev, + "Failed to configure setup register\n"); + return ret; + } + + /* Configure conversion register with the requested chan */ + reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) + | MAX1027_NOSCAN | !!(chan->type == IIO_TEMP); + ret = max1027_write_register(st, reg); + if (ret< 0) { + dev_err(&indio_dev->dev, + "Failed to configure conversion register\n"); + return ret; + } + + /* + * For an unknown reason, when we use the mode "10" (write + * conversion register), the it doesn't occur every time.I still don't understand this comment.
For an unknown reason, the max1027 on my armadeus apf27 don't raise an it when I use the mode "10" (acquisition started on convertion write). In fact, it's weird, there is an IT when I read temperature, but not when I read a voltage. # grep max /proc/interrupts 223: 110213 gpio-mxc 15 max1027 272: 110200 max1027-trigger # cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw 2589 # grep max /proc/interrupts 223: 110213 gpio-mxc 15 max1027 272: 110200 max1027-trigger # cat /sys/bus/iio/devices/iio\:device0/in_temp_raw 214 # grep max /proc/interrupts 223: 110214 gpio-mxc 15 max1027 272: 110200 max1027-trigger So with mode "10", I use a delay of 1 ms.
+ * So we just wait 1 ms. + */ + mdelay(1); + + /* Read result */ + ret = max1027_read_value(st, (chan->type == IIO_TEMP) ? 4 : 2);I guess I didn't have a look into the datasheet before, when reviewing this part, but could you point me to where it is stated, that temperature measurements take 4 bytes?
When the temperature is read, the voltage is also read. So 4 bytes need to be read in the FIFO, 2 for the temperature, 2 for the voltage. This is described in the "Internal FIFO" paragraph.
+ if (ret< 0) + return ret; + + *val = be16_to_cpu(st->buffer[0]); + + return IIO_VAL_INT; +} + +static int max1027_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret = 0; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = max1027_read_single_value(indio_dev, chan, + val, val2, mask); + break; + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_TEMP: + *val = 1; + *val2 = 8; + ret = IIO_VAL_FRACTIONAL; + break; + case IIO_VOLTAGE: + *val = 2500; + *val2 = 10; + ret = IIO_VAL_FRACTIONAL_LOG2; + break; + default: + ret = -EINVAL; + break; + }; + break; + default: + ret = -EINVAL; + break; + }; + + return ret; +} + +static int max1027_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + pr_debug("%s(indio_dev=0x%p, scan_mask=0x%p)\n", + __func__, indio_dev, scan_mask); + + return 0; +} + +static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, + unsigned reg, unsigned writeval, + unsigned *readval) +{ + struct max1027_state *st = iio_priv(indio_dev); + + if (readval != NULL) + return -EINVAL; + + return max1027_write_register(st, writeval); +} + +static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct max1027_state *st = iio_priv(indio_dev); + unsigned char reg; + int ret; + + if (state) { + /* Start acquisition on cnvst */ + reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 | MAX1027_REF_MODE2; + ret = max1027_write_register(st, reg); + if (ret< 0) + return ret; + + /* Scan from 0 to max */ + reg = MAX1027_CONV_REG | MAX1027_CHAN(0) + | MAX1027_SCAN_N_M | MAX1027_TEMP; + ret = max1027_write_register(st, reg); + if (ret< 0) + return ret; + } else { + /* Start acquisition on conversion register write */ + reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;Just for improved readability, keep the same order as above (MSB to LSB in your case).
You're right, it's better, I'll fix it in v3.
+ ret = max1027_write_register(st, reg); + if (ret< 0) + return ret; + } + + return 0; +} + +static irqreturn_t max1027_interrupt_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = (struct iio_dev *)private; + + pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); + + if (iio_buffer_enabled(indio_dev)) + iio_trigger_poll(indio_dev->trig, iio_get_time_ns()); + + return IRQ_HANDLED; +} + +static irqreturn_t max1027_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = (struct iio_poll_func *)private; + struct iio_dev *indio_dev = pf->indio_dev; + struct max1027_state *st = iio_priv(indio_dev); + + pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); + + /* fill buffer with all channel */ + max1027_read_value(st, indio_dev->masklength * 2); + + iio_push_to_buffers_with_timestamp(indio_dev, st->buffer, + iio_get_time_ns()); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static const struct iio_trigger_ops max1027_trigger_ops = { + .owner = THIS_MODULE, + .set_trigger_state =&max1027_set_trigger_state, +}; + +static const struct iio_info max1027_info = { + .driver_module = THIS_MODULE, + .read_raw =&max1027_read_raw, + .update_scan_mode =&max1027_update_scan_mode, + .debugfs_reg_access =&max1027_debugfs_reg_access, +}; + +static int max1027_probe(struct spi_device *spi) +{ + int err; + struct iio_dev *indio_dev; + struct max1027_state *st; + + pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi); + + /* allocate iio device */ + indio_dev = devm_iio_device_alloc(&spi->dev, + sizeof(struct max1027_state)); + if (!indio_dev) { + pr_err("can't allocate iio device\n"); + return -ENOMEM; + } + + spi_set_drvdata(spi, indio_dev); + + st = iio_priv(indio_dev); + st->spi = spi; + st->buffer = NULL; + st->info = (struct max1027_chip_info *) + &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data]; + + /* request irq */ + err = devm_request_threaded_irq(&spi->dev, spi->irq, + max1027_interrupt_handler, + NULL, + IRQF_TRIGGER_FALLING, + spi->dev.driver->name, indio_dev); + if (err) { + dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); + return err; + } + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->dev.parent =&spi->dev; + indio_dev->info =&max1027_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->info->channels; + indio_dev->num_channels = st->info->num_channels; + indio_dev->available_scan_masks = st->info->available_scan_masks; + + /* Allocate buffer (data) */ + st->buffer = devm_kmalloc(&indio_dev->dev, + indio_dev->num_channels * 2, + GFP_KERNEL); + if (st->buffer == NULL) {As picky as I am, I could ask why you check for successful allocation in a different way than above for indio_dev ;-)
I don't really know, but I'll update it to always use the same way for the "post allocation check". I'll update it in v3.
+ dev_err(&indio_dev->dev, "Can't allocate bufffer\n"); + return -ENOMEM; + } + + /* Allocate buffer */ + err = iio_triggered_buffer_setup(indio_dev,&iio_pollfunc_store_time, + &max1027_trigger_handler, NULL); + if (err< 0) { + dev_err(&indio_dev->dev, "Failed to setup buffer\n"); + return err; + } + + /* Allocate trigger */ + st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", + indio_dev->name); + if (st->trig == NULL) { + err = -ENOMEM; + dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n"); + goto fail_trigger_alloc; + } + + /* configure and register trigger */ + st->trig->ops =&max1027_trigger_ops; + st->trig->dev.parent =&spi->dev; + iio_trigger_set_drvdata(st->trig, indio_dev); + iio_trigger_register(st->trig); + + /* Disable averaging */ + err = max1027_write_register(st, MAX1027_AVG_REG); + if (err< 0) { + dev_err(&indio_dev->dev, "Failed to configure averaging register\n"); + goto fail_dev_register; + } + + /* Register the device */ + err = iio_device_register(indio_dev); + if (err< 0) { + dev_err(&indio_dev->dev, "Failed to register iio device\n"); + goto fail_dev_register; + } + + return 0; + +fail_dev_register: +fail_trigger_alloc: + iio_triggered_buffer_cleanup(indio_dev); + + return err; +} + +static int max1027_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + + pr_debug("%s: remove(spi = 0x%p)\n", __func__, spi); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + + return 0; +} + +static struct spi_driver max1027_driver = { + .driver = { + .name = "max1027", + .owner = THIS_MODULE, + }, + .probe = max1027_probe, + .remove = max1027_remove, + .id_table = max1027_id, +}; +module_spi_driver(max1027_driver); + +MODULE_AUTHOR("Philippe Reynes<tremyfr@xxxxxxxx>"); +MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC"); +MODULE_LICENSE("GPL v2");
Best regards, Philippe -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
