![Greg Kroah-Hartman](/assets/img/avatar_default.png)
We want the staging/iio fixes in here as well to handle merge issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
581 lines
14 KiB
C
581 lines
14 KiB
C
/*
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* Support code for Analog Devices Sigma-Delta ADCs
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*
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* Copyright 2012 Analog Devices Inc.
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* Author: Lars-Peter Clausen <lars@metafoo.de>
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/err.h>
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#include <linux/module.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/buffer.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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#include <linux/iio/adc/ad_sigma_delta.h>
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#include <asm/unaligned.h>
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#define AD_SD_COMM_CHAN_MASK 0x3
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#define AD_SD_REG_COMM 0x00
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#define AD_SD_REG_DATA 0x03
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/**
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* ad_sd_set_comm() - Set communications register
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*
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* @sigma_delta: The sigma delta device
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* @comm: New value for the communications register
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*/
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void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm)
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{
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/* Some variants use the lower two bits of the communications register
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* to select the channel */
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sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;
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}
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EXPORT_SYMBOL_GPL(ad_sd_set_comm);
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/**
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* ad_sd_write_reg() - Write a register
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*
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* @sigma_delta: The sigma delta device
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* @reg: Address of the register
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* @size: Size of the register (0-3)
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* @val: Value to write to the register
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*
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* Returns 0 on success, an error code otherwise.
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**/
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int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
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unsigned int size, unsigned int val)
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{
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uint8_t *data = sigma_delta->data;
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struct spi_transfer t = {
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.tx_buf = data,
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.len = size + 1,
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.cs_change = sigma_delta->bus_locked,
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};
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struct spi_message m;
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int ret;
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data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;
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switch (size) {
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case 3:
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data[1] = val >> 16;
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data[2] = val >> 8;
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data[3] = val;
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break;
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case 2:
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put_unaligned_be16(val, &data[1]);
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break;
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case 1:
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data[1] = val;
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break;
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case 0:
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break;
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default:
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return -EINVAL;
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}
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spi_message_init(&m);
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spi_message_add_tail(&t, &m);
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if (sigma_delta->bus_locked)
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ret = spi_sync_locked(sigma_delta->spi, &m);
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else
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ret = spi_sync(sigma_delta->spi, &m);
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return ret;
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}
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EXPORT_SYMBOL_GPL(ad_sd_write_reg);
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static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta,
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unsigned int reg, unsigned int size, uint8_t *val)
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{
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uint8_t *data = sigma_delta->data;
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int ret;
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struct spi_transfer t[] = {
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{
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.tx_buf = data,
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.len = 1,
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}, {
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.rx_buf = val,
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.len = size,
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.cs_change = sigma_delta->bus_locked,
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},
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};
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struct spi_message m;
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spi_message_init(&m);
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if (sigma_delta->info->has_registers) {
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data[0] = reg << sigma_delta->info->addr_shift;
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data[0] |= sigma_delta->info->read_mask;
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spi_message_add_tail(&t[0], &m);
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}
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spi_message_add_tail(&t[1], &m);
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if (sigma_delta->bus_locked)
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ret = spi_sync_locked(sigma_delta->spi, &m);
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else
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ret = spi_sync(sigma_delta->spi, &m);
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return ret;
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}
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/**
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* ad_sd_read_reg() - Read a register
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*
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* @sigma_delta: The sigma delta device
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* @reg: Address of the register
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* @size: Size of the register (1-4)
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* @val: Read value
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*
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* Returns 0 on success, an error code otherwise.
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**/
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int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta,
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unsigned int reg, unsigned int size, unsigned int *val)
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{
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int ret;
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ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->data);
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if (ret < 0)
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goto out;
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switch (size) {
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case 4:
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*val = get_unaligned_be32(sigma_delta->data);
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break;
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case 3:
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*val = (sigma_delta->data[0] << 16) |
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(sigma_delta->data[1] << 8) |
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sigma_delta->data[2];
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break;
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case 2:
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*val = get_unaligned_be16(sigma_delta->data);
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break;
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case 1:
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*val = sigma_delta->data[0];
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break;
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default:
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ret = -EINVAL;
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break;
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}
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out:
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return ret;
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}
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EXPORT_SYMBOL_GPL(ad_sd_read_reg);
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/**
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* ad_sd_reset() - Reset the serial interface
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*
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* @sigma_delta: The sigma delta device
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* @reset_length: Number of SCLKs with DIN = 1
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*
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* Returns 0 on success, an error code otherwise.
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**/
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int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
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unsigned int reset_length)
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{
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uint8_t *buf;
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unsigned int size;
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int ret;
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size = DIV_ROUND_UP(reset_length, 8);
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buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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memset(buf, 0xff, size);
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ret = spi_write(sigma_delta->spi, buf, size);
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kfree(buf);
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return ret;
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}
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EXPORT_SYMBOL_GPL(ad_sd_reset);
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static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
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unsigned int mode, unsigned int channel)
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{
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int ret;
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ret = ad_sigma_delta_set_channel(sigma_delta, channel);
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if (ret)
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return ret;
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spi_bus_lock(sigma_delta->spi->master);
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sigma_delta->bus_locked = true;
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reinit_completion(&sigma_delta->completion);
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ret = ad_sigma_delta_set_mode(sigma_delta, mode);
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if (ret < 0)
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goto out;
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sigma_delta->irq_dis = false;
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enable_irq(sigma_delta->spi->irq);
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ret = wait_for_completion_timeout(&sigma_delta->completion, 2*HZ);
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if (ret == 0) {
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sigma_delta->irq_dis = true;
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disable_irq_nosync(sigma_delta->spi->irq);
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ret = -EIO;
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} else {
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ret = 0;
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}
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out:
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sigma_delta->bus_locked = false;
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spi_bus_unlock(sigma_delta->spi->master);
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ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
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return ret;
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}
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/**
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* ad_sd_calibrate_all() - Performs channel calibration
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* @sigma_delta: The sigma delta device
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* @cb: Array of channels and calibration type to perform
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* @n: Number of items in cb
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*
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* Returns 0 on success, an error code otherwise.
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**/
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int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
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const struct ad_sd_calib_data *cb, unsigned int n)
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{
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unsigned int i;
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int ret;
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for (i = 0; i < n; i++) {
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ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel);
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if (ret)
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return ret;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(ad_sd_calibrate_all);
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/**
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* ad_sigma_delta_single_conversion() - Performs a single data conversion
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* @indio_dev: The IIO device
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* @chan: The conversion is done for this channel
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* @val: Pointer to the location where to store the read value
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*
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* Returns: 0 on success, an error value otherwise.
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*/
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int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, int *val)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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unsigned int sample, raw_sample;
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int ret = 0;
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if (iio_buffer_enabled(indio_dev))
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return -EBUSY;
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mutex_lock(&indio_dev->mlock);
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ad_sigma_delta_set_channel(sigma_delta, chan->address);
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spi_bus_lock(sigma_delta->spi->master);
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sigma_delta->bus_locked = true;
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reinit_completion(&sigma_delta->completion);
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ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE);
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sigma_delta->irq_dis = false;
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enable_irq(sigma_delta->spi->irq);
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ret = wait_for_completion_interruptible_timeout(
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&sigma_delta->completion, HZ);
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sigma_delta->bus_locked = false;
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spi_bus_unlock(sigma_delta->spi->master);
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if (ret == 0)
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ret = -EIO;
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if (ret < 0)
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goto out;
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ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA,
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DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
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&raw_sample);
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out:
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if (!sigma_delta->irq_dis) {
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disable_irq_nosync(sigma_delta->spi->irq);
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sigma_delta->irq_dis = true;
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}
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ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
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mutex_unlock(&indio_dev->mlock);
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if (ret)
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return ret;
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sample = raw_sample >> chan->scan_type.shift;
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sample &= (1 << chan->scan_type.realbits) - 1;
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*val = sample;
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ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample);
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if (ret)
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return ret;
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return IIO_VAL_INT;
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}
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EXPORT_SYMBOL_GPL(ad_sigma_delta_single_conversion);
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static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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unsigned int channel;
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int ret;
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ret = iio_triggered_buffer_postenable(indio_dev);
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if (ret < 0)
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return ret;
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channel = find_first_bit(indio_dev->active_scan_mask,
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indio_dev->masklength);
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ret = ad_sigma_delta_set_channel(sigma_delta,
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indio_dev->channels[channel].address);
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if (ret)
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goto err_predisable;
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spi_bus_lock(sigma_delta->spi->master);
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sigma_delta->bus_locked = true;
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ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS);
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if (ret)
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goto err_unlock;
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sigma_delta->irq_dis = false;
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enable_irq(sigma_delta->spi->irq);
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return 0;
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err_unlock:
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spi_bus_unlock(sigma_delta->spi->master);
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err_predisable:
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return ret;
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}
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static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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reinit_completion(&sigma_delta->completion);
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wait_for_completion_timeout(&sigma_delta->completion, HZ);
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if (!sigma_delta->irq_dis) {
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disable_irq_nosync(sigma_delta->spi->irq);
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sigma_delta->irq_dis = true;
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}
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ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
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sigma_delta->bus_locked = false;
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return spi_bus_unlock(sigma_delta->spi->master);
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}
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static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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unsigned int reg_size;
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uint8_t data[16];
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int ret;
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memset(data, 0x00, 16);
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reg_size = indio_dev->channels[0].scan_type.realbits +
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indio_dev->channels[0].scan_type.shift;
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reg_size = DIV_ROUND_UP(reg_size, 8);
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switch (reg_size) {
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case 4:
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case 2:
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case 1:
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ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
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reg_size, &data[0]);
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break;
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case 3:
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/* We store 24 bit samples in a 32 bit word. Keep the upper
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* byte set to zero. */
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ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
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reg_size, &data[1]);
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break;
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}
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iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp);
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iio_trigger_notify_done(indio_dev->trig);
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sigma_delta->irq_dis = false;
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enable_irq(sigma_delta->spi->irq);
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return IRQ_HANDLED;
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}
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static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = {
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.postenable = &ad_sd_buffer_postenable,
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.predisable = &iio_triggered_buffer_predisable,
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.postdisable = &ad_sd_buffer_postdisable,
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.validate_scan_mask = &iio_validate_scan_mask_onehot,
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};
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static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private)
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{
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struct ad_sigma_delta *sigma_delta = private;
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complete(&sigma_delta->completion);
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disable_irq_nosync(irq);
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sigma_delta->irq_dis = true;
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iio_trigger_poll(sigma_delta->trig);
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return IRQ_HANDLED;
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}
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/**
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* ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
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* @indio_dev: The IIO device
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* @trig: The new trigger
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*
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* Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta
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* device, -EINVAL otherwise.
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*/
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int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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if (sigma_delta->trig != trig)
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return -EINVAL;
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return 0;
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}
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EXPORT_SYMBOL_GPL(ad_sd_validate_trigger);
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static const struct iio_trigger_ops ad_sd_trigger_ops = {
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};
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static int ad_sd_probe_trigger(struct iio_dev *indio_dev)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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int ret;
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sigma_delta->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
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indio_dev->id);
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if (sigma_delta->trig == NULL) {
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ret = -ENOMEM;
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goto error_ret;
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}
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sigma_delta->trig->ops = &ad_sd_trigger_ops;
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init_completion(&sigma_delta->completion);
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ret = request_irq(sigma_delta->spi->irq,
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ad_sd_data_rdy_trig_poll,
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IRQF_TRIGGER_LOW,
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indio_dev->name,
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sigma_delta);
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if (ret)
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goto error_free_trig;
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if (!sigma_delta->irq_dis) {
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sigma_delta->irq_dis = true;
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disable_irq_nosync(sigma_delta->spi->irq);
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}
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sigma_delta->trig->dev.parent = &sigma_delta->spi->dev;
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iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta);
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ret = iio_trigger_register(sigma_delta->trig);
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if (ret)
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goto error_free_irq;
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/* select default trigger */
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indio_dev->trig = iio_trigger_get(sigma_delta->trig);
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return 0;
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error_free_irq:
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free_irq(sigma_delta->spi->irq, sigma_delta);
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error_free_trig:
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iio_trigger_free(sigma_delta->trig);
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error_ret:
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return ret;
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}
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static void ad_sd_remove_trigger(struct iio_dev *indio_dev)
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{
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struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
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iio_trigger_unregister(sigma_delta->trig);
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free_irq(sigma_delta->spi->irq, sigma_delta);
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iio_trigger_free(sigma_delta->trig);
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}
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/**
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* ad_sd_setup_buffer_and_trigger() -
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* @indio_dev: The IIO device
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*/
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int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev)
|
|
{
|
|
int ret;
|
|
|
|
ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
|
|
&ad_sd_trigger_handler, &ad_sd_buffer_setup_ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = ad_sd_probe_trigger(indio_dev);
|
|
if (ret) {
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ad_sd_setup_buffer_and_trigger);
|
|
|
|
/**
|
|
* ad_sd_cleanup_buffer_and_trigger() -
|
|
* @indio_dev: The IIO device
|
|
*/
|
|
void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev)
|
|
{
|
|
ad_sd_remove_trigger(indio_dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger);
|
|
|
|
/**
|
|
* ad_sd_init() - Initializes a ad_sigma_delta struct
|
|
* @sigma_delta: The ad_sigma_delta device
|
|
* @indio_dev: The IIO device which the Sigma Delta device is used for
|
|
* @spi: The SPI device for the ad_sigma_delta device
|
|
* @info: Device specific callbacks and options
|
|
*
|
|
* This function needs to be called before any other operations are performed on
|
|
* the ad_sigma_delta struct.
|
|
*/
|
|
int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
|
|
struct spi_device *spi, const struct ad_sigma_delta_info *info)
|
|
{
|
|
sigma_delta->spi = spi;
|
|
sigma_delta->info = info;
|
|
iio_device_set_drvdata(indio_dev, sigma_delta);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ad_sd_init);
|
|
|
|
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
|
|
MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");
|
|
MODULE_LICENSE("GPL v2");
|