diff options
Diffstat (limited to 'drivers/iio/counter')
| -rw-r--r-- | drivers/iio/counter/104-quad-8.c | 631 | ||||
| -rw-r--r-- | drivers/iio/counter/Kconfig | 34 | ||||
| -rw-r--r-- | drivers/iio/counter/Makefile | 8 | ||||
| -rw-r--r-- | drivers/iio/counter/stm32-lptimer-cnt.c | 382 |
4 files changed, 1055 insertions, 0 deletions
diff --git a/drivers/iio/counter/104-quad-8.c b/drivers/iio/counter/104-quad-8.c new file mode 100644 index 000000000..92be8d0f7 --- /dev/null +++ b/drivers/iio/counter/104-quad-8.c @@ -0,0 +1,631 @@ +/* + * IIO driver for the ACCES 104-QUAD-8 + * Copyright (C) 2016 William Breathitt Gray + * + * 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. + * + * 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. + * + * This driver supports the ACCES 104-QUAD-8 and ACCES 104-QUAD-4. + */ +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/iio/iio.h> +#include <linux/iio/types.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/isa.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#define QUAD8_EXTENT 32 + +static unsigned int base[max_num_isa_dev(QUAD8_EXTENT)]; +static unsigned int num_quad8; +module_param_array(base, uint, &num_quad8, 0); +MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); + +#define QUAD8_NUM_COUNTERS 8 + +/** + * struct quad8_iio - IIO device private data structure + * @preset: array of preset values + * @count_mode: array of count mode configurations + * @quadrature_mode: array of quadrature mode configurations + * @quadrature_scale: array of quadrature mode scale configurations + * @ab_enable: array of A and B inputs enable configurations + * @preset_enable: array of set_to_preset_on_index attribute configurations + * @synchronous_mode: array of index function synchronous mode configurations + * @index_polarity: array of index function polarity configurations + * @base: base port address of the IIO device + */ +struct quad8_iio { + unsigned int preset[QUAD8_NUM_COUNTERS]; + unsigned int count_mode[QUAD8_NUM_COUNTERS]; + unsigned int quadrature_mode[QUAD8_NUM_COUNTERS]; + unsigned int quadrature_scale[QUAD8_NUM_COUNTERS]; + unsigned int ab_enable[QUAD8_NUM_COUNTERS]; + unsigned int preset_enable[QUAD8_NUM_COUNTERS]; + unsigned int synchronous_mode[QUAD8_NUM_COUNTERS]; + unsigned int index_polarity[QUAD8_NUM_COUNTERS]; + unsigned int base; +}; + +#define QUAD8_REG_CHAN_OP 0x11 +#define QUAD8_REG_INDEX_INPUT_LEVELS 0x16 +/* Borrow Toggle flip-flop */ +#define QUAD8_FLAG_BT BIT(0) +/* Carry Toggle flip-flop */ +#define QUAD8_FLAG_CT BIT(1) +/* Error flag */ +#define QUAD8_FLAG_E BIT(4) +/* Up/Down flag */ +#define QUAD8_FLAG_UD BIT(5) +/* Reset and Load Signal Decoders */ +#define QUAD8_CTR_RLD 0x00 +/* Counter Mode Register */ +#define QUAD8_CTR_CMR 0x20 +/* Input / Output Control Register */ +#define QUAD8_CTR_IOR 0x40 +/* Index Control Register */ +#define QUAD8_CTR_IDR 0x60 +/* Reset Byte Pointer (three byte data pointer) */ +#define QUAD8_RLD_RESET_BP 0x01 +/* Reset Counter */ +#define QUAD8_RLD_RESET_CNTR 0x02 +/* Reset Borrow Toggle, Carry Toggle, Compare Toggle, and Sign flags */ +#define QUAD8_RLD_RESET_FLAGS 0x04 +/* Reset Error flag */ +#define QUAD8_RLD_RESET_E 0x06 +/* Preset Register to Counter */ +#define QUAD8_RLD_PRESET_CNTR 0x08 +/* Transfer Counter to Output Latch */ +#define QUAD8_RLD_CNTR_OUT 0x10 +#define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00 +#define QUAD8_CHAN_OP_RESET_COUNTERS 0x01 + +static int quad8_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, int *val2, long mask) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel; + unsigned int flags; + unsigned int borrow; + unsigned int carry; + int i; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type == IIO_INDEX) { + *val = !!(inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS) + & BIT(chan->channel)); + return IIO_VAL_INT; + } + + flags = inb(base_offset + 1); + borrow = flags & QUAD8_FLAG_BT; + carry = !!(flags & QUAD8_FLAG_CT); + + /* Borrow XOR Carry effectively doubles count range */ + *val = (borrow ^ carry) << 24; + + /* Reset Byte Pointer; transfer Counter to Output Latch */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT, + base_offset + 1); + + for (i = 0; i < 3; i++) + *val |= (unsigned int)inb(base_offset) << (8 * i); + + return IIO_VAL_INT; + case IIO_CHAN_INFO_ENABLE: + *val = priv->ab_enable[chan->channel]; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 1; + *val2 = priv->quadrature_scale[chan->channel]; + return IIO_VAL_FRACTIONAL_LOG2; + } + + return -EINVAL; +} + +static int quad8_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long mask) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel; + int i; + unsigned int ior_cfg; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type == IIO_INDEX) + return -EINVAL; + + /* Only 24-bit values are supported */ + if ((unsigned int)val > 0xFFFFFF) + return -EINVAL; + + /* Reset Byte Pointer */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); + + /* Counter can only be set via Preset Register */ + for (i = 0; i < 3; i++) + outb(val >> (8 * i), base_offset); + + /* Transfer Preset Register to Counter */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1); + + /* Reset Byte Pointer */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); + + /* Set Preset Register back to original value */ + val = priv->preset[chan->channel]; + for (i = 0; i < 3; i++) + outb(val >> (8 * i), base_offset); + + /* Reset Borrow, Carry, Compare, and Sign flags */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1); + /* Reset Error flag */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1); + + return 0; + case IIO_CHAN_INFO_ENABLE: + /* only boolean values accepted */ + if (val < 0 || val > 1) + return -EINVAL; + + priv->ab_enable[chan->channel] = val; + + ior_cfg = val | priv->preset_enable[chan->channel] << 1; + + /* Load I/O control configuration */ + outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1); + + return 0; + case IIO_CHAN_INFO_SCALE: + /* Quadrature scaling only available in quadrature mode */ + if (!priv->quadrature_mode[chan->channel] && (val2 || val != 1)) + return -EINVAL; + + /* Only three gain states (1, 0.5, 0.25) */ + if (val == 1 && !val2) + priv->quadrature_scale[chan->channel] = 0; + else if (!val) + switch (val2) { + case 500000: + priv->quadrature_scale[chan->channel] = 1; + break; + case 250000: + priv->quadrature_scale[chan->channel] = 2; + break; + default: + return -EINVAL; + } + else + return -EINVAL; + + return 0; + } + + return -EINVAL; +} + +static const struct iio_info quad8_info = { + .read_raw = quad8_read_raw, + .write_raw = quad8_write_raw +}; + +static ssize_t quad8_read_preset(struct iio_dev *indio_dev, uintptr_t private, + const struct iio_chan_spec *chan, char *buf) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset[chan->channel]); +} + +static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private, + const struct iio_chan_spec *chan, const char *buf, size_t len) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel; + unsigned int preset; + int ret; + int i; + + ret = kstrtouint(buf, 0, &preset); + if (ret) + return ret; + + /* Only 24-bit values are supported */ + if (preset > 0xFFFFFF) + return -EINVAL; + + priv->preset[chan->channel] = preset; + + /* Reset Byte Pointer */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); + + /* Set Preset Register */ + for (i = 0; i < 3; i++) + outb(preset >> (8 * i), base_offset); + + return len; +} + +static ssize_t quad8_read_set_to_preset_on_index(struct iio_dev *indio_dev, + uintptr_t private, const struct iio_chan_spec *chan, char *buf) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%u\n", + !priv->preset_enable[chan->channel]); +} + +static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev, + uintptr_t private, const struct iio_chan_spec *chan, const char *buf, + size_t len) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel + 1; + bool preset_enable; + int ret; + unsigned int ior_cfg; + + ret = kstrtobool(buf, &preset_enable); + if (ret) + return ret; + + /* Preset enable is active low in Input/Output Control register */ + preset_enable = !preset_enable; + + priv->preset_enable[chan->channel] = preset_enable; + + ior_cfg = priv->ab_enable[chan->channel] | + (unsigned int)preset_enable << 1; + + /* Load I/O control configuration to Input / Output Control Register */ + outb(QUAD8_CTR_IOR | ior_cfg, base_offset); + + return len; +} + +static const char *const quad8_noise_error_states[] = { + "No excessive noise is present at the count inputs", + "Excessive noise is present at the count inputs" +}; + +static int quad8_get_noise_error(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel + 1; + + return !!(inb(base_offset) & QUAD8_FLAG_E); +} + +static const struct iio_enum quad8_noise_error_enum = { + .items = quad8_noise_error_states, + .num_items = ARRAY_SIZE(quad8_noise_error_states), + .get = quad8_get_noise_error +}; + +static const char *const quad8_count_direction_states[] = { + "down", + "up" +}; + +static int quad8_get_count_direction(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const int base_offset = priv->base + 2 * chan->channel + 1; + + return !!(inb(base_offset) & QUAD8_FLAG_UD); +} + +static const struct iio_enum quad8_count_direction_enum = { + .items = quad8_count_direction_states, + .num_items = ARRAY_SIZE(quad8_count_direction_states), + .get = quad8_get_count_direction +}; + +static const char *const quad8_count_modes[] = { + "normal", + "range limit", + "non-recycle", + "modulo-n" +}; + +static int quad8_set_count_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, unsigned int count_mode) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + unsigned int mode_cfg = count_mode << 1; + const int base_offset = priv->base + 2 * chan->channel + 1; + + priv->count_mode[chan->channel] = count_mode; + + /* Add quadrature mode configuration */ + if (priv->quadrature_mode[chan->channel]) + mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3; + + /* Load mode configuration to Counter Mode Register */ + outb(QUAD8_CTR_CMR | mode_cfg, base_offset); + + return 0; +} + +static int quad8_get_count_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return priv->count_mode[chan->channel]; +} + +static const struct iio_enum quad8_count_mode_enum = { + .items = quad8_count_modes, + .num_items = ARRAY_SIZE(quad8_count_modes), + .set = quad8_set_count_mode, + .get = quad8_get_count_mode +}; + +static const char *const quad8_synchronous_modes[] = { + "non-synchronous", + "synchronous" +}; + +static int quad8_set_synchronous_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, unsigned int synchronous_mode) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const unsigned int idr_cfg = synchronous_mode | + priv->index_polarity[chan->channel] << 1; + const int base_offset = priv->base + 2 * chan->channel + 1; + + /* Index function must be non-synchronous in non-quadrature mode */ + if (synchronous_mode && !priv->quadrature_mode[chan->channel]) + return -EINVAL; + + priv->synchronous_mode[chan->channel] = synchronous_mode; + + /* Load Index Control configuration to Index Control Register */ + outb(QUAD8_CTR_IDR | idr_cfg, base_offset); + + return 0; +} + +static int quad8_get_synchronous_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return priv->synchronous_mode[chan->channel]; +} + +static const struct iio_enum quad8_synchronous_mode_enum = { + .items = quad8_synchronous_modes, + .num_items = ARRAY_SIZE(quad8_synchronous_modes), + .set = quad8_set_synchronous_mode, + .get = quad8_get_synchronous_mode +}; + +static const char *const quad8_quadrature_modes[] = { + "non-quadrature", + "quadrature" +}; + +static int quad8_set_quadrature_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, unsigned int quadrature_mode) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + unsigned int mode_cfg = priv->count_mode[chan->channel] << 1; + const int base_offset = priv->base + 2 * chan->channel + 1; + + if (quadrature_mode) + mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3; + else { + /* Quadrature scaling only available in quadrature mode */ + priv->quadrature_scale[chan->channel] = 0; + + /* Synchronous function not supported in non-quadrature mode */ + if (priv->synchronous_mode[chan->channel]) + quad8_set_synchronous_mode(indio_dev, chan, 0); + } + + priv->quadrature_mode[chan->channel] = quadrature_mode; + + /* Load mode configuration to Counter Mode Register */ + outb(QUAD8_CTR_CMR | mode_cfg, base_offset); + + return 0; +} + +static int quad8_get_quadrature_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return priv->quadrature_mode[chan->channel]; +} + +static const struct iio_enum quad8_quadrature_mode_enum = { + .items = quad8_quadrature_modes, + .num_items = ARRAY_SIZE(quad8_quadrature_modes), + .set = quad8_set_quadrature_mode, + .get = quad8_get_quadrature_mode +}; + +static const char *const quad8_index_polarity_modes[] = { + "negative", + "positive" +}; + +static int quad8_set_index_polarity(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, unsigned int index_polarity) +{ + struct quad8_iio *const priv = iio_priv(indio_dev); + const unsigned int idr_cfg = priv->synchronous_mode[chan->channel] | + index_polarity << 1; + const int base_offset = priv->base + 2 * chan->channel + 1; + + priv->index_polarity[chan->channel] = index_polarity; + + /* Load Index Control configuration to Index Control Register */ + outb(QUAD8_CTR_IDR | idr_cfg, base_offset); + + return 0; +} + +static int quad8_get_index_polarity(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + const struct quad8_iio *const priv = iio_priv(indio_dev); + + return priv->index_polarity[chan->channel]; +} + +static const struct iio_enum quad8_index_polarity_enum = { + .items = quad8_index_polarity_modes, + .num_items = ARRAY_SIZE(quad8_index_polarity_modes), + .set = quad8_set_index_polarity, + .get = quad8_get_index_polarity +}; + +static const struct iio_chan_spec_ext_info quad8_count_ext_info[] = { + { + .name = "preset", + .shared = IIO_SEPARATE, + .read = quad8_read_preset, + .write = quad8_write_preset + }, + { + .name = "set_to_preset_on_index", + .shared = IIO_SEPARATE, + .read = quad8_read_set_to_preset_on_index, + .write = quad8_write_set_to_preset_on_index + }, + IIO_ENUM("noise_error", IIO_SEPARATE, &quad8_noise_error_enum), + IIO_ENUM_AVAILABLE("noise_error", &quad8_noise_error_enum), + IIO_ENUM("count_direction", IIO_SEPARATE, &quad8_count_direction_enum), + IIO_ENUM_AVAILABLE("count_direction", &quad8_count_direction_enum), + IIO_ENUM("count_mode", IIO_SEPARATE, &quad8_count_mode_enum), + IIO_ENUM_AVAILABLE("count_mode", &quad8_count_mode_enum), + IIO_ENUM("quadrature_mode", IIO_SEPARATE, &quad8_quadrature_mode_enum), + IIO_ENUM_AVAILABLE("quadrature_mode", &quad8_quadrature_mode_enum), + {} +}; + +static const struct iio_chan_spec_ext_info quad8_index_ext_info[] = { + IIO_ENUM("synchronous_mode", IIO_SEPARATE, + &quad8_synchronous_mode_enum), + IIO_ENUM_AVAILABLE("synchronous_mode", &quad8_synchronous_mode_enum), + IIO_ENUM("index_polarity", IIO_SEPARATE, &quad8_index_polarity_enum), + IIO_ENUM_AVAILABLE("index_polarity", &quad8_index_polarity_enum), + {} +}; + +#define QUAD8_COUNT_CHAN(_chan) { \ + .type = IIO_COUNT, \ + .channel = (_chan), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_ENABLE) | BIT(IIO_CHAN_INFO_SCALE), \ + .ext_info = quad8_count_ext_info, \ + .indexed = 1 \ +} + +#define QUAD8_INDEX_CHAN(_chan) { \ + .type = IIO_INDEX, \ + .channel = (_chan), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .ext_info = quad8_index_ext_info, \ + .indexed = 1 \ +} + +static const struct iio_chan_spec quad8_channels[] = { + QUAD8_COUNT_CHAN(0), QUAD8_INDEX_CHAN(0), + QUAD8_COUNT_CHAN(1), QUAD8_INDEX_CHAN(1), + QUAD8_COUNT_CHAN(2), QUAD8_INDEX_CHAN(2), + QUAD8_COUNT_CHAN(3), QUAD8_INDEX_CHAN(3), + QUAD8_COUNT_CHAN(4), QUAD8_INDEX_CHAN(4), + QUAD8_COUNT_CHAN(5), QUAD8_INDEX_CHAN(5), + QUAD8_COUNT_CHAN(6), QUAD8_INDEX_CHAN(6), + QUAD8_COUNT_CHAN(7), QUAD8_INDEX_CHAN(7) +}; + +static int quad8_probe(struct device *dev, unsigned int id) +{ + struct iio_dev *indio_dev; + struct quad8_iio *priv; + int i, j; + unsigned int base_offset; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + if (!devm_request_region(dev, base[id], QUAD8_EXTENT, + dev_name(dev))) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base[id], base[id] + QUAD8_EXTENT); + return -EBUSY; + } + + indio_dev->info = &quad8_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->num_channels = ARRAY_SIZE(quad8_channels); + indio_dev->channels = quad8_channels; + indio_dev->name = dev_name(dev); + indio_dev->dev.parent = dev; + + priv = iio_priv(indio_dev); + priv->base = base[id]; + + /* Reset all counters and disable interrupt function */ + outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP); + /* Set initial configuration for all counters */ + for (i = 0; i < QUAD8_NUM_COUNTERS; i++) { + base_offset = base[id] + 2 * i; + /* Reset Byte Pointer */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); + /* Reset Preset Register */ + for (j = 0; j < 3; j++) + outb(0x00, base_offset); + /* Reset Borrow, Carry, Compare, and Sign flags */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1); + /* Reset Error flag */ + outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1); + /* Binary encoding; Normal count; non-quadrature mode */ + outb(QUAD8_CTR_CMR, base_offset + 1); + /* Disable A and B inputs; preset on index; FLG1 as Carry */ + outb(QUAD8_CTR_IOR, base_offset + 1); + /* Disable index function; negative index polarity */ + outb(QUAD8_CTR_IDR, base_offset + 1); + } + /* Enable all counters */ + outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP); + + return devm_iio_device_register(dev, indio_dev); +} + +static struct isa_driver quad8_driver = { + .probe = quad8_probe, + .driver = { + .name = "104-quad-8" + } +}; + +module_isa_driver(quad8_driver, num_quad8); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("ACCES 104-QUAD-8 IIO driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/iio/counter/Kconfig b/drivers/iio/counter/Kconfig new file mode 100644 index 000000000..bf1e559ad --- /dev/null +++ b/drivers/iio/counter/Kconfig @@ -0,0 +1,34 @@ +# +# Counter devices +# +# When adding new entries keep the list in alphabetical order + +menu "Counters" + +config 104_QUAD_8 + tristate "ACCES 104-QUAD-8 driver" + depends on PC104 && X86 + select ISA_BUS_API + help + Say yes here to build support for the ACCES 104-QUAD-8 quadrature + encoder counter/interface device family (104-QUAD-8, 104-QUAD-4). + + Performing a write to a counter's IIO_CHAN_INFO_RAW sets the counter and + also clears the counter's respective error flag. Although the counters + have a 25-bit range, only the lower 24 bits may be set, either directly + or via a counter's preset attribute. Interrupts are not supported by + this driver. + + The base port addresses for the devices may be configured via the base + array module parameter. + +config STM32_LPTIMER_CNT + tristate "STM32 LP Timer encoder counter driver" + depends on MFD_STM32_LPTIMER || COMPILE_TEST + help + Select this option to enable STM32 Low-Power Timer quadrature encoder + and counter driver. + + To compile this driver as a module, choose M here: the + module will be called stm32-lptimer-cnt. +endmenu diff --git a/drivers/iio/counter/Makefile b/drivers/iio/counter/Makefile new file mode 100644 index 000000000..1b9a896eb --- /dev/null +++ b/drivers/iio/counter/Makefile @@ -0,0 +1,8 @@ +# +# Makefile for IIO counter devices +# + +# When adding new entries keep the list in alphabetical order + +obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o +obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c new file mode 100644 index 000000000..42fb8ba67 --- /dev/null +++ b/drivers/iio/counter/stm32-lptimer-cnt.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * STM32 Low-Power Timer Encoder and Counter driver + * + * Copyright (C) STMicroelectronics 2017 + * + * Author: Fabrice Gasnier <fabrice.gasnier@st.com> + * + * Inspired by 104-quad-8 and stm32-timer-trigger drivers. + * + */ + +#include <linux/bitfield.h> +#include <linux/iio/iio.h> +#include <linux/mfd/stm32-lptimer.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +struct stm32_lptim_cnt { + struct device *dev; + struct regmap *regmap; + struct clk *clk; + u32 preset; + u32 polarity; + u32 quadrature_mode; +}; + +static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv) +{ + u32 val; + int ret; + + ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val); + if (ret) + return ret; + + return FIELD_GET(STM32_LPTIM_ENABLE, val); +} + +static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, + int enable) +{ + int ret; + u32 val; + + val = FIELD_PREP(STM32_LPTIM_ENABLE, enable); + ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val); + if (ret) + return ret; + + if (!enable) { + clk_disable(priv->clk); + return 0; + } + + /* LP timer must be enabled before writing CMP & ARR */ + ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->preset); + if (ret) + return ret; + + ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0); + if (ret) + return ret; + + /* ensure CMP & ARR registers are properly written */ + ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val, + (val & STM32_LPTIM_CMPOK_ARROK), + 100, 1000); + if (ret) + return ret; + + ret = regmap_write(priv->regmap, STM32_LPTIM_ICR, + STM32_LPTIM_CMPOKCF_ARROKCF); + if (ret) + return ret; + + ret = clk_enable(priv->clk); + if (ret) { + regmap_write(priv->regmap, STM32_LPTIM_CR, 0); + return ret; + } + + /* Start LP timer in continuous mode */ + return regmap_update_bits(priv->regmap, STM32_LPTIM_CR, + STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT); +} + +static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable) +{ + u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE | + STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC; + u32 val; + + /* Setup LP timer encoder/counter and polarity, without prescaler */ + if (priv->quadrature_mode) + val = enable ? STM32_LPTIM_ENC : 0; + else + val = enable ? STM32_LPTIM_COUNTMODE : 0; + val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0); + + return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val); +} + +static int stm32_lptim_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_ENABLE: + if (val < 0 || val > 1) + return -EINVAL; + + /* Check nobody uses the timer, or already disabled/enabled */ + ret = stm32_lptim_is_enabled(priv); + if ((ret < 0) || (!ret && !val)) + return ret; + if (val && ret) + return -EBUSY; + + ret = stm32_lptim_setup(priv, val); + if (ret) + return ret; + return stm32_lptim_set_enable_state(priv, val); + + default: + return -EINVAL; + } +} + +static int stm32_lptim_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + u32 dat; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat); + if (ret) + return ret; + *val = dat; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_ENABLE: + ret = stm32_lptim_is_enabled(priv); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + /* Non-quadrature mode: scale = 1 */ + *val = 1; + *val2 = 0; + if (priv->quadrature_mode) { + /* + * Quadrature encoder mode: + * - both edges, quarter cycle, scale is 0.25 + * - either rising/falling edge scale is 0.5 + */ + if (priv->polarity > 1) + *val2 = 2; + else + *val2 = 1; + } + return IIO_VAL_FRACTIONAL_LOG2; + + default: + return -EINVAL; + } +} + +static const struct iio_info stm32_lptim_cnt_iio_info = { + .read_raw = stm32_lptim_read_raw, + .write_raw = stm32_lptim_write_raw, +}; + +static const char *const stm32_lptim_quadrature_modes[] = { + "non-quadrature", + "quadrature", +}; + +static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + + return priv->quadrature_mode; +} + +static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int type) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + + if (stm32_lptim_is_enabled(priv)) + return -EBUSY; + + priv->quadrature_mode = type; + + return 0; +} + +static const struct iio_enum stm32_lptim_quadrature_mode_en = { + .items = stm32_lptim_quadrature_modes, + .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes), + .get = stm32_lptim_get_quadrature_mode, + .set = stm32_lptim_set_quadrature_mode, +}; + +static const char * const stm32_lptim_cnt_polarity[] = { + "rising-edge", "falling-edge", "both-edges", +}; + +static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + + return priv->polarity; +} + +static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int type) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + + if (stm32_lptim_is_enabled(priv)) + return -EBUSY; + + priv->polarity = type; + + return 0; +} + +static const struct iio_enum stm32_lptim_cnt_polarity_en = { + .items = stm32_lptim_cnt_polarity, + .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity), + .get = stm32_lptim_cnt_get_polarity, + .set = stm32_lptim_cnt_set_polarity, +}; + +static ssize_t stm32_lptim_cnt_get_preset(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + + return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset); +} + +static ssize_t stm32_lptim_cnt_set_preset(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct stm32_lptim_cnt *priv = iio_priv(indio_dev); + int ret; + + if (stm32_lptim_is_enabled(priv)) + return -EBUSY; + + ret = kstrtouint(buf, 0, &priv->preset); + if (ret) + return ret; + + if (priv->preset > STM32_LPTIM_MAX_ARR) + return -EINVAL; + + return len; +} + +/* LP timer with encoder */ +static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = { + { + .name = "preset", + .shared = IIO_SEPARATE, + .read = stm32_lptim_cnt_get_preset, + .write = stm32_lptim_cnt_set_preset, + }, + IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), + IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), + IIO_ENUM("quadrature_mode", IIO_SEPARATE, + &stm32_lptim_quadrature_mode_en), + IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en), + {} +}; + +static const struct iio_chan_spec stm32_lptim_enc_channels = { + .type = IIO_COUNT, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_ENABLE) | + BIT(IIO_CHAN_INFO_SCALE), + .ext_info = stm32_lptim_enc_ext_info, + .indexed = 1, +}; + +/* LP timer without encoder (counter only) */ +static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = { + { + .name = "preset", + .shared = IIO_SEPARATE, + .read = stm32_lptim_cnt_get_preset, + .write = stm32_lptim_cnt_set_preset, + }, + IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), + IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), + {} +}; + +static const struct iio_chan_spec stm32_lptim_cnt_channels = { + .type = IIO_COUNT, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_ENABLE) | + BIT(IIO_CHAN_INFO_SCALE), + .ext_info = stm32_lptim_cnt_ext_info, + .indexed = 1, +}; + +static int stm32_lptim_cnt_probe(struct platform_device *pdev) +{ + struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent); + struct stm32_lptim_cnt *priv; + struct iio_dev *indio_dev; + + if (IS_ERR_OR_NULL(ddata)) + return -EINVAL; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + priv = iio_priv(indio_dev); + priv->dev = &pdev->dev; + priv->regmap = ddata->regmap; + priv->clk = ddata->clk; + priv->preset = STM32_LPTIM_MAX_ARR; + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->dev.parent = &pdev->dev; + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->info = &stm32_lptim_cnt_iio_info; + if (ddata->has_encoder) + indio_dev->channels = &stm32_lptim_enc_channels; + else + indio_dev->channels = &stm32_lptim_cnt_channels; + indio_dev->num_channels = 1; + + platform_set_drvdata(pdev, priv); + + return devm_iio_device_register(&pdev->dev, indio_dev); +} + +static const struct of_device_id stm32_lptim_cnt_of_match[] = { + { .compatible = "st,stm32-lptimer-counter", }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match); + +static struct platform_driver stm32_lptim_cnt_driver = { + .probe = stm32_lptim_cnt_probe, + .driver = { + .name = "stm32-lptimer-counter", + .of_match_table = stm32_lptim_cnt_of_match, + }, +}; +module_platform_driver(stm32_lptim_cnt_driver); + +MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); +MODULE_ALIAS("platform:stm32-lptimer-counter"); +MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver"); +MODULE_LICENSE("GPL v2"); |