linux/drivers/counter/104-quad-8.c
William Breathitt Gray 98ffe02529 counter: 104-quad-8: Migrate to the regmap API
The regmap API supports IO port accessors so we can take advantage of
regmap abstractions rather than handling access to the device registers
directly in the driver. With regmap we get boundary checks, read-write
permissions, operation synchronization locks, and more for free. Most
important of all, rather than rolling our own we utilize implementations
that are known to work and gain from any future improvements and fixes
that come.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/1f1f7920d2be94aedb6fdf49f429fe6137c8cb24.1681753140.git.william.gray@linaro.org/
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
2023-05-18 20:39:46 -04:00

1364 lines
37 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Counter driver for the ACCES 104-QUAD-8
* Copyright (C) 2016 William Breathitt Gray
*
* This driver supports the ACCES 104-QUAD-8 and ACCES 104-QUAD-4.
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/counter.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/isa.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/regmap.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/unaligned.h>
#define QUAD8_EXTENT 32
static unsigned int base[max_num_isa_dev(QUAD8_EXTENT)];
static unsigned int num_quad8;
module_param_hw_array(base, uint, ioport, &num_quad8, 0);
MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
static unsigned int irq[max_num_isa_dev(QUAD8_EXTENT)];
static unsigned int num_irq;
module_param_hw_array(irq, uint, irq, &num_irq, 0);
MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
#define QUAD8_NUM_COUNTERS 8
#define QUAD8_DATA(_channel) ((_channel) * 2)
#define QUAD8_CONTROL(_channel) (QUAD8_DATA(_channel) + 1)
#define QUAD8_INTERRUPT_STATUS 0x10
#define QUAD8_CHANNEL_OPERATION 0x11
#define QUAD8_INDEX_INTERRUPT 0x12
#define QUAD8_INDEX_INPUT_LEVELS 0x16
#define QUAD8_CABLE_STATUS 0x17
/**
* struct quad8 - device private data structure
* @lock: lock to prevent clobbering device states during R/W ops
* @cmr: array of Counter Mode Register states
* @ior: array of Input / Output Control Register states
* @idr: array of Index Control Register states
* @fck_prescaler: array of filter clock prescaler configurations
* @preset: array of preset values
* @cable_fault_enable: differential encoder cable status enable configurations
* @map: regmap for the device
*/
struct quad8 {
spinlock_t lock;
u8 cmr[QUAD8_NUM_COUNTERS];
u8 ior[QUAD8_NUM_COUNTERS];
u8 idr[QUAD8_NUM_COUNTERS];
unsigned int fck_prescaler[QUAD8_NUM_COUNTERS];
unsigned int preset[QUAD8_NUM_COUNTERS];
unsigned int cable_fault_enable;
struct regmap *map;
};
static const struct regmap_range quad8_wr_ranges[] = {
regmap_reg_range(0x0, 0xF), regmap_reg_range(0x11, 0x12), regmap_reg_range(0x17, 0x17),
};
static const struct regmap_range quad8_rd_ranges[] = {
regmap_reg_range(0x0, 0x12), regmap_reg_range(0x16, 0x18),
};
static const struct regmap_access_table quad8_wr_table = {
.yes_ranges = quad8_wr_ranges,
.n_yes_ranges = ARRAY_SIZE(quad8_wr_ranges),
};
static const struct regmap_access_table quad8_rd_table = {
.yes_ranges = quad8_rd_ranges,
.n_yes_ranges = ARRAY_SIZE(quad8_rd_ranges),
};
static const struct regmap_config quad8_regmap_config = {
.reg_bits = 8,
.reg_stride = 1,
.val_bits = 8,
.io_port = true,
.wr_table = &quad8_wr_table,
.rd_table = &quad8_rd_table,
};
/* Error flag */
#define FLAG_E BIT(4)
/* Up/Down flag */
#define FLAG_UD BIT(5)
/* Counting up */
#define UP 0x1
#define REGISTER_SELECTION GENMASK(6, 5)
/* Reset and Load Signal Decoders */
#define SELECT_RLD u8_encode_bits(0x0, REGISTER_SELECTION)
/* Counter Mode Register */
#define SELECT_CMR u8_encode_bits(0x1, REGISTER_SELECTION)
/* Input / Output Control Register */
#define SELECT_IOR u8_encode_bits(0x2, REGISTER_SELECTION)
/* Index Control Register */
#define SELECT_IDR u8_encode_bits(0x3, REGISTER_SELECTION)
/*
* Reset and Load Signal Decoders
*/
#define RESETS GENMASK(2, 1)
#define LOADS GENMASK(4, 3)
/* Reset Byte Pointer (three byte data pointer) */
#define RESET_BP BIT(0)
/* Reset Borrow Toggle, Carry toggle, Compare toggle, Sign, and Index flags */
#define RESET_BT_CT_CPT_S_IDX u8_encode_bits(0x2, RESETS)
/* Reset Error flag */
#define RESET_E u8_encode_bits(0x3, RESETS)
/* Preset Register to Counter */
#define TRANSFER_PR_TO_CNTR u8_encode_bits(0x1, LOADS)
/* Transfer Counter to Output Latch */
#define TRANSFER_CNTR_TO_OL u8_encode_bits(0x2, LOADS)
/* Transfer Preset Register LSB to FCK Prescaler */
#define TRANSFER_PR0_TO_PSC u8_encode_bits(0x3, LOADS)
/*
* Counter Mode Registers
*/
#define COUNT_ENCODING BIT(0)
#define COUNT_MODE GENMASK(2, 1)
#define QUADRATURE_MODE GENMASK(4, 3)
/* Binary count */
#define BINARY u8_encode_bits(0x0, COUNT_ENCODING)
/* Normal count */
#define NORMAL_COUNT 0x0
/* Range Limit */
#define RANGE_LIMIT 0x1
/* Non-recycle count */
#define NON_RECYCLE_COUNT 0x2
/* Modulo-N */
#define MODULO_N 0x3
/* Non-quadrature */
#define NON_QUADRATURE 0x0
/* Quadrature X1 */
#define QUADRATURE_X1 0x1
/* Quadrature X2 */
#define QUADRATURE_X2 0x2
/* Quadrature X4 */
#define QUADRATURE_X4 0x3
/*
* Input/Output Control Register
*/
#define AB_GATE BIT(0)
#define LOAD_PIN BIT(1)
#define FLG_PINS GENMASK(4, 3)
/* Disable inputs A and B */
#define DISABLE_AB u8_encode_bits(0x0, AB_GATE)
/* Load Counter input */
#define LOAD_CNTR 0x0
/* FLG1 = CARRY(active low); FLG2 = BORROW(active low) */
#define FLG1_CARRY_FLG2_BORROW 0x0
/* FLG1 = COMPARE(active low); FLG2 = BORROW(active low) */
#define FLG1_COMPARE_FLG2_BORROW 0x1
/* FLG1 = Carry(active low)/Borrow(active low); FLG2 = U/D(active low) flag */
#define FLG1_CARRYBORROW_FLG2_UD 0x2
/* FLG1 = INDX (low pulse at INDEX pin active level); FLG2 = E flag */
#define FLG1_INDX_FLG2_E 0x3
/*
* INDEX CONTROL REGISTERS
*/
#define INDEX_MODE BIT(0)
#define INDEX_POLARITY BIT(1)
/* Disable Index mode */
#define DISABLE_INDEX_MODE 0x0
/* Enable Index mode */
#define ENABLE_INDEX_MODE 0x1
/* Negative Index Polarity */
#define NEGATIVE_INDEX_POLARITY 0x0
/* Positive Index Polarity */
#define POSITIVE_INDEX_POLARITY 0x1
/*
* Channel Operation Register
*/
#define COUNTERS_OPERATION BIT(0)
#define INTERRUPT_FUNCTION BIT(2)
/* Enable all Counters */
#define ENABLE_COUNTERS u8_encode_bits(0x0, COUNTERS_OPERATION)
/* Reset all Counters */
#define RESET_COUNTERS u8_encode_bits(0x1, COUNTERS_OPERATION)
/* Disable the interrupt function */
#define DISABLE_INTERRUPT_FUNCTION u8_encode_bits(0x0, INTERRUPT_FUNCTION)
/* Enable the interrupt function */
#define ENABLE_INTERRUPT_FUNCTION u8_encode_bits(0x1, INTERRUPT_FUNCTION)
/* Any write to the Channel Operation register clears any pending interrupts */
#define CLEAR_PENDING_INTERRUPTS (ENABLE_COUNTERS | ENABLE_INTERRUPT_FUNCTION)
/* Each Counter is 24 bits wide */
#define LS7267_CNTR_MAX GENMASK(23, 0)
static __always_inline int quad8_control_register_update(struct regmap *const map, u8 *const buf,
const size_t channel, const u8 val,
const u8 field)
{
u8p_replace_bits(&buf[channel], val, field);
return regmap_write(map, QUAD8_CONTROL(channel), buf[channel]);
}
static int quad8_signal_read(struct counter_device *counter,
struct counter_signal *signal,
enum counter_signal_level *level)
{
const struct quad8 *const priv = counter_priv(counter);
int ret;
/* Only Index signal levels can be read */
if (signal->id < 16)
return -EINVAL;
ret = regmap_test_bits(priv->map, QUAD8_INDEX_INPUT_LEVELS, BIT(signal->id - 16));
if (ret < 0)
return ret;
*level = (ret) ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
return 0;
}
static int quad8_count_read(struct counter_device *counter,
struct counter_count *count, u64 *val)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
u8 value[3];
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
ret = regmap_write(priv->map, QUAD8_CONTROL(count->id),
SELECT_RLD | RESET_BP | TRANSFER_CNTR_TO_OL);
if (ret)
goto exit_unlock;
ret = regmap_noinc_read(priv->map, QUAD8_DATA(count->id), value, sizeof(value));
exit_unlock:
spin_unlock_irqrestore(&priv->lock, irqflags);
*val = get_unaligned_le24(value);
return ret;
}
static int quad8_preset_register_set(struct quad8 *const priv, const size_t id,
const unsigned long preset)
{
u8 value[3];
int ret;
put_unaligned_le24(preset, value);
ret = regmap_write(priv->map, QUAD8_CONTROL(id), SELECT_RLD | RESET_BP);
if (ret)
return ret;
return regmap_noinc_write(priv->map, QUAD8_DATA(id), value, sizeof(value));
}
static int quad8_flag_register_reset(struct quad8 *const priv, const size_t id)
{
int ret;
ret = regmap_write(priv->map, QUAD8_CONTROL(id), SELECT_RLD | RESET_BT_CT_CPT_S_IDX);
if (ret)
return ret;
return regmap_write(priv->map, QUAD8_CONTROL(id), SELECT_RLD | RESET_E);
}
static int quad8_count_write(struct counter_device *counter,
struct counter_count *count, u64 val)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int ret;
if (val > LS7267_CNTR_MAX)
return -ERANGE;
spin_lock_irqsave(&priv->lock, irqflags);
/* Counter can only be set via Preset Register */
ret = quad8_preset_register_set(priv, count->id, val);
if (ret)
goto exit_unlock;
ret = regmap_write(priv->map, QUAD8_CONTROL(count->id), SELECT_RLD | TRANSFER_PR_TO_CNTR);
if (ret)
goto exit_unlock;
ret = quad8_flag_register_reset(priv, count->id);
if (ret)
goto exit_unlock;
/* Set Preset Register back to original value */
ret = quad8_preset_register_set(priv, count->id, priv->preset[count->id]);
exit_unlock:
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static const enum counter_function quad8_count_functions_list[] = {
COUNTER_FUNCTION_PULSE_DIRECTION,
COUNTER_FUNCTION_QUADRATURE_X1_A,
COUNTER_FUNCTION_QUADRATURE_X2_A,
COUNTER_FUNCTION_QUADRATURE_X4,
};
static int quad8_function_get(const struct quad8 *const priv, const size_t id,
enum counter_function *const function)
{
switch (u8_get_bits(priv->cmr[id], QUADRATURE_MODE)) {
case NON_QUADRATURE:
*function = COUNTER_FUNCTION_PULSE_DIRECTION;
return 0;
case QUADRATURE_X1:
*function = COUNTER_FUNCTION_QUADRATURE_X1_A;
return 0;
case QUADRATURE_X2:
*function = COUNTER_FUNCTION_QUADRATURE_X2_A;
return 0;
case QUADRATURE_X4:
*function = COUNTER_FUNCTION_QUADRATURE_X4;
return 0;
default:
/* should never reach this path */
return -EINVAL;
}
}
static int quad8_function_read(struct counter_device *counter,
struct counter_count *count,
enum counter_function *function)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int retval;
spin_lock_irqsave(&priv->lock, irqflags);
retval = quad8_function_get(priv, count->id, function);
spin_unlock_irqrestore(&priv->lock, irqflags);
return retval;
}
static int quad8_function_write(struct counter_device *counter,
struct counter_count *count,
enum counter_function function)
{
struct quad8 *const priv = counter_priv(counter);
const int id = count->id;
unsigned long irqflags;
unsigned int mode_cfg;
bool synchronous_mode;
int ret;
switch (function) {
case COUNTER_FUNCTION_PULSE_DIRECTION:
mode_cfg = NON_QUADRATURE;
break;
case COUNTER_FUNCTION_QUADRATURE_X1_A:
mode_cfg = QUADRATURE_X1;
break;
case COUNTER_FUNCTION_QUADRATURE_X2_A:
mode_cfg = QUADRATURE_X2;
break;
case COUNTER_FUNCTION_QUADRATURE_X4:
mode_cfg = QUADRATURE_X4;
break;
default:
/* should never reach this path */
return -EINVAL;
}
spin_lock_irqsave(&priv->lock, irqflags);
/* Synchronous function not supported in non-quadrature mode */
synchronous_mode = u8_get_bits(priv->idr[id], INDEX_MODE) == ENABLE_INDEX_MODE;
if (synchronous_mode && mode_cfg == NON_QUADRATURE) {
ret = quad8_control_register_update(priv->map, priv->idr, id, DISABLE_INDEX_MODE,
INDEX_MODE);
if (ret)
goto exit_unlock;
}
ret = quad8_control_register_update(priv->map, priv->cmr, id, mode_cfg, QUADRATURE_MODE);
exit_unlock:
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_direction_read(struct counter_device *counter,
struct counter_count *count,
enum counter_count_direction *direction)
{
const struct quad8 *const priv = counter_priv(counter);
unsigned int flag;
int ret;
ret = regmap_read(priv->map, QUAD8_CONTROL(count->id), &flag);
if (ret)
return ret;
*direction = (u8_get_bits(flag, FLAG_UD) == UP) ? COUNTER_COUNT_DIRECTION_FORWARD :
COUNTER_COUNT_DIRECTION_BACKWARD;
return 0;
}
static const enum counter_synapse_action quad8_index_actions_list[] = {
COUNTER_SYNAPSE_ACTION_NONE,
COUNTER_SYNAPSE_ACTION_RISING_EDGE,
};
static const enum counter_synapse_action quad8_synapse_actions_list[] = {
COUNTER_SYNAPSE_ACTION_NONE,
COUNTER_SYNAPSE_ACTION_RISING_EDGE,
COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
};
static int quad8_action_read(struct counter_device *counter,
struct counter_count *count,
struct counter_synapse *synapse,
enum counter_synapse_action *action)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int err;
enum counter_function function;
const size_t signal_a_id = count->synapses[0].signal->id;
enum counter_count_direction direction;
/* Default action mode */
*action = COUNTER_SYNAPSE_ACTION_NONE;
/* Handle Index signals */
if (synapse->signal->id >= 16) {
if (u8_get_bits(priv->ior[count->id], LOAD_PIN) == LOAD_CNTR)
*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
return 0;
}
spin_lock_irqsave(&priv->lock, irqflags);
/* Get Count function and direction atomically */
err = quad8_function_get(priv, count->id, &function);
if (err) {
spin_unlock_irqrestore(&priv->lock, irqflags);
return err;
}
err = quad8_direction_read(counter, count, &direction);
if (err) {
spin_unlock_irqrestore(&priv->lock, irqflags);
return err;
}
spin_unlock_irqrestore(&priv->lock, irqflags);
/* Determine action mode based on current count function mode */
switch (function) {
case COUNTER_FUNCTION_PULSE_DIRECTION:
if (synapse->signal->id == signal_a_id)
*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X1_A:
if (synapse->signal->id == signal_a_id) {
if (direction == COUNTER_COUNT_DIRECTION_FORWARD)
*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
else
*action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
}
return 0;
case COUNTER_FUNCTION_QUADRATURE_X2_A:
if (synapse->signal->id == signal_a_id)
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
return 0;
case COUNTER_FUNCTION_QUADRATURE_X4:
*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
return 0;
default:
/* should never reach this path */
return -EINVAL;
}
}
static int quad8_events_configure(struct counter_device *counter)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irq_enabled = 0;
unsigned long irqflags;
struct counter_event_node *event_node;
u8 flg_pins;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
list_for_each_entry(event_node, &counter->events_list, l) {
switch (event_node->event) {
case COUNTER_EVENT_OVERFLOW:
flg_pins = FLG1_CARRY_FLG2_BORROW;
break;
case COUNTER_EVENT_THRESHOLD:
flg_pins = FLG1_COMPARE_FLG2_BORROW;
break;
case COUNTER_EVENT_OVERFLOW_UNDERFLOW:
flg_pins = FLG1_CARRYBORROW_FLG2_UD;
break;
case COUNTER_EVENT_INDEX:
flg_pins = FLG1_INDX_FLG2_E;
break;
default:
/* should never reach this path */
ret = -EINVAL;
goto exit_unlock;
}
/* Enable IRQ line */
irq_enabled |= BIT(event_node->channel);
/* Skip configuration if it is the same as previously set */
if (flg_pins == u8_get_bits(priv->ior[event_node->channel], FLG_PINS))
continue;
/* Save new IRQ function configuration */
ret = quad8_control_register_update(priv->map, priv->ior, event_node->channel,
flg_pins, FLG_PINS);
if (ret)
goto exit_unlock;
}
ret = regmap_write(priv->map, QUAD8_INDEX_INTERRUPT, irq_enabled);
exit_unlock:
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_watch_validate(struct counter_device *counter,
const struct counter_watch *watch)
{
struct counter_event_node *event_node;
if (watch->channel > QUAD8_NUM_COUNTERS - 1)
return -EINVAL;
switch (watch->event) {
case COUNTER_EVENT_OVERFLOW:
case COUNTER_EVENT_THRESHOLD:
case COUNTER_EVENT_OVERFLOW_UNDERFLOW:
case COUNTER_EVENT_INDEX:
list_for_each_entry(event_node, &counter->next_events_list, l)
if (watch->channel == event_node->channel &&
watch->event != event_node->event)
return -EINVAL;
return 0;
default:
return -EINVAL;
}
}
static const struct counter_ops quad8_ops = {
.signal_read = quad8_signal_read,
.count_read = quad8_count_read,
.count_write = quad8_count_write,
.function_read = quad8_function_read,
.function_write = quad8_function_write,
.action_read = quad8_action_read,
.events_configure = quad8_events_configure,
.watch_validate = quad8_watch_validate,
};
static const char *const quad8_index_polarity_modes[] = {
"negative",
"positive"
};
static int quad8_index_polarity_get(struct counter_device *counter,
struct counter_signal *signal,
u32 *index_polarity)
{
const struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id - 16;
*index_polarity = u8_get_bits(priv->idr[channel_id], INDEX_POLARITY);
return 0;
}
static int quad8_index_polarity_set(struct counter_device *counter,
struct counter_signal *signal,
u32 index_polarity)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id - 16;
unsigned long irqflags;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
ret = quad8_control_register_update(priv->map, priv->idr, channel_id, index_polarity,
INDEX_POLARITY);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_polarity_read(struct counter_device *counter,
struct counter_signal *signal,
enum counter_signal_polarity *polarity)
{
int err;
u32 index_polarity;
err = quad8_index_polarity_get(counter, signal, &index_polarity);
if (err)
return err;
*polarity = (index_polarity == POSITIVE_INDEX_POLARITY) ? COUNTER_SIGNAL_POLARITY_POSITIVE :
COUNTER_SIGNAL_POLARITY_NEGATIVE;
return 0;
}
static int quad8_polarity_write(struct counter_device *counter,
struct counter_signal *signal,
enum counter_signal_polarity polarity)
{
const u32 pol = (polarity == COUNTER_SIGNAL_POLARITY_POSITIVE) ? POSITIVE_INDEX_POLARITY :
NEGATIVE_INDEX_POLARITY;
return quad8_index_polarity_set(counter, signal, pol);
}
static const char *const quad8_synchronous_modes[] = {
"non-synchronous",
"synchronous"
};
static int quad8_synchronous_mode_get(struct counter_device *counter,
struct counter_signal *signal,
u32 *synchronous_mode)
{
const struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id - 16;
*synchronous_mode = u8_get_bits(priv->idr[channel_id], INDEX_MODE);
return 0;
}
static int quad8_synchronous_mode_set(struct counter_device *counter,
struct counter_signal *signal,
u32 synchronous_mode)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id - 16;
u8 quadrature_mode;
unsigned long irqflags;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
/* Index function must be non-synchronous in non-quadrature mode */
quadrature_mode = u8_get_bits(priv->idr[channel_id], QUADRATURE_MODE);
if (synchronous_mode && quadrature_mode == NON_QUADRATURE) {
ret = -EINVAL;
goto exit_unlock;
}
ret = quad8_control_register_update(priv->map, priv->idr, channel_id, synchronous_mode,
INDEX_MODE);
exit_unlock:
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_count_floor_read(struct counter_device *counter,
struct counter_count *count, u64 *floor)
{
/* Only a floor of 0 is supported */
*floor = 0;
return 0;
}
static int quad8_count_mode_read(struct counter_device *counter,
struct counter_count *count,
enum counter_count_mode *cnt_mode)
{
const struct quad8 *const priv = counter_priv(counter);
switch (u8_get_bits(priv->cmr[count->id], COUNT_MODE)) {
case NORMAL_COUNT:
*cnt_mode = COUNTER_COUNT_MODE_NORMAL;
break;
case RANGE_LIMIT:
*cnt_mode = COUNTER_COUNT_MODE_RANGE_LIMIT;
break;
case NON_RECYCLE_COUNT:
*cnt_mode = COUNTER_COUNT_MODE_NON_RECYCLE;
break;
case MODULO_N:
*cnt_mode = COUNTER_COUNT_MODE_MODULO_N;
break;
}
return 0;
}
static int quad8_count_mode_write(struct counter_device *counter,
struct counter_count *count,
enum counter_count_mode cnt_mode)
{
struct quad8 *const priv = counter_priv(counter);
unsigned int count_mode;
unsigned long irqflags;
int ret;
switch (cnt_mode) {
case COUNTER_COUNT_MODE_NORMAL:
count_mode = NORMAL_COUNT;
break;
case COUNTER_COUNT_MODE_RANGE_LIMIT:
count_mode = RANGE_LIMIT;
break;
case COUNTER_COUNT_MODE_NON_RECYCLE:
count_mode = NON_RECYCLE_COUNT;
break;
case COUNTER_COUNT_MODE_MODULO_N:
count_mode = MODULO_N;
break;
default:
/* should never reach this path */
return -EINVAL;
}
spin_lock_irqsave(&priv->lock, irqflags);
ret = quad8_control_register_update(priv->map, priv->cmr, count->id, count_mode,
COUNT_MODE);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_count_enable_read(struct counter_device *counter,
struct counter_count *count, u8 *enable)
{
const struct quad8 *const priv = counter_priv(counter);
*enable = u8_get_bits(priv->ior[count->id], AB_GATE);
return 0;
}
static int quad8_count_enable_write(struct counter_device *counter,
struct counter_count *count, u8 enable)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
ret = quad8_control_register_update(priv->map, priv->ior, count->id, enable, AB_GATE);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
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_error_noise_get(struct counter_device *counter,
struct counter_count *count, u32 *noise_error)
{
const struct quad8 *const priv = counter_priv(counter);
unsigned int flag;
int ret;
ret = regmap_read(priv->map, QUAD8_CONTROL(count->id), &flag);
if (ret)
return ret;
*noise_error = u8_get_bits(flag, FLAG_E);
return 0;
}
static int quad8_count_preset_read(struct counter_device *counter,
struct counter_count *count, u64 *preset)
{
const struct quad8 *const priv = counter_priv(counter);
*preset = priv->preset[count->id];
return 0;
}
static int quad8_count_preset_write(struct counter_device *counter,
struct counter_count *count, u64 preset)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int ret;
if (preset > LS7267_CNTR_MAX)
return -ERANGE;
spin_lock_irqsave(&priv->lock, irqflags);
priv->preset[count->id] = preset;
ret = quad8_preset_register_set(priv, count->id, preset);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_count_ceiling_read(struct counter_device *counter,
struct counter_count *count, u64 *ceiling)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
spin_lock_irqsave(&priv->lock, irqflags);
/* Range Limit and Modulo-N count modes use preset value as ceiling */
switch (u8_get_bits(priv->cmr[count->id], COUNT_MODE)) {
case RANGE_LIMIT:
case MODULO_N:
*ceiling = priv->preset[count->id];
break;
default:
*ceiling = LS7267_CNTR_MAX;
break;
}
spin_unlock_irqrestore(&priv->lock, irqflags);
return 0;
}
static int quad8_count_ceiling_write(struct counter_device *counter,
struct counter_count *count, u64 ceiling)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int ret;
if (ceiling > LS7267_CNTR_MAX)
return -ERANGE;
spin_lock_irqsave(&priv->lock, irqflags);
/* Range Limit and Modulo-N count modes use preset value as ceiling */
switch (u8_get_bits(priv->cmr[count->id], COUNT_MODE)) {
case RANGE_LIMIT:
case MODULO_N:
priv->preset[count->id] = ceiling;
ret = quad8_preset_register_set(priv, count->id, ceiling);
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_count_preset_enable_read(struct counter_device *counter,
struct counter_count *count,
u8 *preset_enable)
{
const struct quad8 *const priv = counter_priv(counter);
/* Preset enable is active low in Input/Output Control register */
*preset_enable = !u8_get_bits(priv->ior[count->id], LOAD_PIN);
return 0;
}
static int quad8_count_preset_enable_write(struct counter_device *counter,
struct counter_count *count,
u8 preset_enable)
{
struct quad8 *const priv = counter_priv(counter);
unsigned long irqflags;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
/* Preset enable is active low in Input/Output Control register */
ret = quad8_control_register_update(priv->map, priv->ior, count->id, !preset_enable,
LOAD_PIN);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_signal_cable_fault_read(struct counter_device *counter,
struct counter_signal *signal,
u8 *cable_fault)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id / 2;
unsigned long irqflags;
bool disabled;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
disabled = !(priv->cable_fault_enable & BIT(channel_id));
if (disabled) {
spin_unlock_irqrestore(&priv->lock, irqflags);
return -EINVAL;
}
ret = regmap_test_bits(priv->map, QUAD8_CABLE_STATUS, BIT(channel_id));
if (ret < 0) {
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
spin_unlock_irqrestore(&priv->lock, irqflags);
/* Logic 0 = cable fault */
*cable_fault = !ret;
return 0;
}
static int quad8_signal_cable_fault_enable_read(struct counter_device *counter,
struct counter_signal *signal,
u8 *enable)
{
const struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id / 2;
*enable = !!(priv->cable_fault_enable & BIT(channel_id));
return 0;
}
static int quad8_signal_cable_fault_enable_write(struct counter_device *counter,
struct counter_signal *signal,
u8 enable)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id / 2;
unsigned long irqflags;
unsigned int cable_fault_enable;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
if (enable)
priv->cable_fault_enable |= BIT(channel_id);
else
priv->cable_fault_enable &= ~BIT(channel_id);
/* Enable is active low in Differential Encoder Cable Status register */
cable_fault_enable = ~priv->cable_fault_enable;
ret = regmap_write(priv->map, QUAD8_CABLE_STATUS, cable_fault_enable);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static int quad8_signal_fck_prescaler_read(struct counter_device *counter,
struct counter_signal *signal,
u8 *prescaler)
{
const struct quad8 *const priv = counter_priv(counter);
*prescaler = priv->fck_prescaler[signal->id / 2];
return 0;
}
static int quad8_filter_clock_prescaler_set(struct quad8 *const priv, const size_t id,
const u8 prescaler)
{
int ret;
ret = regmap_write(priv->map, QUAD8_CONTROL(id), SELECT_RLD | RESET_BP);
if (ret)
return ret;
ret = regmap_write(priv->map, QUAD8_DATA(id), prescaler);
if (ret)
return ret;
return regmap_write(priv->map, QUAD8_CONTROL(id), SELECT_RLD | TRANSFER_PR0_TO_PSC);
}
static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
struct counter_signal *signal,
u8 prescaler)
{
struct quad8 *const priv = counter_priv(counter);
const size_t channel_id = signal->id / 2;
unsigned long irqflags;
int ret;
spin_lock_irqsave(&priv->lock, irqflags);
priv->fck_prescaler[channel_id] = prescaler;
ret = quad8_filter_clock_prescaler_set(priv, channel_id, prescaler);
spin_unlock_irqrestore(&priv->lock, irqflags);
return ret;
}
static struct counter_comp quad8_signal_ext[] = {
COUNTER_COMP_SIGNAL_BOOL("cable_fault", quad8_signal_cable_fault_read,
NULL),
COUNTER_COMP_SIGNAL_BOOL("cable_fault_enable",
quad8_signal_cable_fault_enable_read,
quad8_signal_cable_fault_enable_write),
COUNTER_COMP_SIGNAL_U8("filter_clock_prescaler",
quad8_signal_fck_prescaler_read,
quad8_signal_fck_prescaler_write)
};
static const enum counter_signal_polarity quad8_polarities[] = {
COUNTER_SIGNAL_POLARITY_POSITIVE,
COUNTER_SIGNAL_POLARITY_NEGATIVE,
};
static DEFINE_COUNTER_AVAILABLE(quad8_polarity_available, quad8_polarities);
static DEFINE_COUNTER_ENUM(quad8_index_pol_enum, quad8_index_polarity_modes);
static DEFINE_COUNTER_ENUM(quad8_synch_mode_enum, quad8_synchronous_modes);
static struct counter_comp quad8_index_ext[] = {
COUNTER_COMP_SIGNAL_ENUM("index_polarity", quad8_index_polarity_get,
quad8_index_polarity_set,
quad8_index_pol_enum),
COUNTER_COMP_POLARITY(quad8_polarity_read, quad8_polarity_write,
quad8_polarity_available),
COUNTER_COMP_SIGNAL_ENUM("synchronous_mode", quad8_synchronous_mode_get,
quad8_synchronous_mode_set,
quad8_synch_mode_enum),
};
#define QUAD8_QUAD_SIGNAL(_id, _name) { \
.id = (_id), \
.name = (_name), \
.ext = quad8_signal_ext, \
.num_ext = ARRAY_SIZE(quad8_signal_ext) \
}
#define QUAD8_INDEX_SIGNAL(_id, _name) { \
.id = (_id), \
.name = (_name), \
.ext = quad8_index_ext, \
.num_ext = ARRAY_SIZE(quad8_index_ext) \
}
static struct counter_signal quad8_signals[] = {
QUAD8_QUAD_SIGNAL(0, "Channel 1 Quadrature A"),
QUAD8_QUAD_SIGNAL(1, "Channel 1 Quadrature B"),
QUAD8_QUAD_SIGNAL(2, "Channel 2 Quadrature A"),
QUAD8_QUAD_SIGNAL(3, "Channel 2 Quadrature B"),
QUAD8_QUAD_SIGNAL(4, "Channel 3 Quadrature A"),
QUAD8_QUAD_SIGNAL(5, "Channel 3 Quadrature B"),
QUAD8_QUAD_SIGNAL(6, "Channel 4 Quadrature A"),
QUAD8_QUAD_SIGNAL(7, "Channel 4 Quadrature B"),
QUAD8_QUAD_SIGNAL(8, "Channel 5 Quadrature A"),
QUAD8_QUAD_SIGNAL(9, "Channel 5 Quadrature B"),
QUAD8_QUAD_SIGNAL(10, "Channel 6 Quadrature A"),
QUAD8_QUAD_SIGNAL(11, "Channel 6 Quadrature B"),
QUAD8_QUAD_SIGNAL(12, "Channel 7 Quadrature A"),
QUAD8_QUAD_SIGNAL(13, "Channel 7 Quadrature B"),
QUAD8_QUAD_SIGNAL(14, "Channel 8 Quadrature A"),
QUAD8_QUAD_SIGNAL(15, "Channel 8 Quadrature B"),
QUAD8_INDEX_SIGNAL(16, "Channel 1 Index"),
QUAD8_INDEX_SIGNAL(17, "Channel 2 Index"),
QUAD8_INDEX_SIGNAL(18, "Channel 3 Index"),
QUAD8_INDEX_SIGNAL(19, "Channel 4 Index"),
QUAD8_INDEX_SIGNAL(20, "Channel 5 Index"),
QUAD8_INDEX_SIGNAL(21, "Channel 6 Index"),
QUAD8_INDEX_SIGNAL(22, "Channel 7 Index"),
QUAD8_INDEX_SIGNAL(23, "Channel 8 Index")
};
#define QUAD8_COUNT_SYNAPSES(_id) { \
{ \
.actions_list = quad8_synapse_actions_list, \
.num_actions = ARRAY_SIZE(quad8_synapse_actions_list), \
.signal = quad8_signals + 2 * (_id) \
}, \
{ \
.actions_list = quad8_synapse_actions_list, \
.num_actions = ARRAY_SIZE(quad8_synapse_actions_list), \
.signal = quad8_signals + 2 * (_id) + 1 \
}, \
{ \
.actions_list = quad8_index_actions_list, \
.num_actions = ARRAY_SIZE(quad8_index_actions_list), \
.signal = quad8_signals + 2 * (_id) + 16 \
} \
}
static struct counter_synapse quad8_count_synapses[][3] = {
QUAD8_COUNT_SYNAPSES(0), QUAD8_COUNT_SYNAPSES(1),
QUAD8_COUNT_SYNAPSES(2), QUAD8_COUNT_SYNAPSES(3),
QUAD8_COUNT_SYNAPSES(4), QUAD8_COUNT_SYNAPSES(5),
QUAD8_COUNT_SYNAPSES(6), QUAD8_COUNT_SYNAPSES(7)
};
static const enum counter_count_mode quad8_cnt_modes[] = {
COUNTER_COUNT_MODE_NORMAL,
COUNTER_COUNT_MODE_RANGE_LIMIT,
COUNTER_COUNT_MODE_NON_RECYCLE,
COUNTER_COUNT_MODE_MODULO_N,
};
static DEFINE_COUNTER_AVAILABLE(quad8_count_mode_available, quad8_cnt_modes);
static DEFINE_COUNTER_ENUM(quad8_error_noise_enum, quad8_noise_error_states);
static struct counter_comp quad8_count_ext[] = {
COUNTER_COMP_CEILING(quad8_count_ceiling_read,
quad8_count_ceiling_write),
COUNTER_COMP_FLOOR(quad8_count_floor_read, NULL),
COUNTER_COMP_COUNT_MODE(quad8_count_mode_read, quad8_count_mode_write,
quad8_count_mode_available),
COUNTER_COMP_DIRECTION(quad8_direction_read),
COUNTER_COMP_ENABLE(quad8_count_enable_read, quad8_count_enable_write),
COUNTER_COMP_COUNT_ENUM("error_noise", quad8_error_noise_get, NULL,
quad8_error_noise_enum),
COUNTER_COMP_PRESET(quad8_count_preset_read, quad8_count_preset_write),
COUNTER_COMP_PRESET_ENABLE(quad8_count_preset_enable_read,
quad8_count_preset_enable_write),
};
#define QUAD8_COUNT(_id, _cntname) { \
.id = (_id), \
.name = (_cntname), \
.functions_list = quad8_count_functions_list, \
.num_functions = ARRAY_SIZE(quad8_count_functions_list), \
.synapses = quad8_count_synapses[(_id)], \
.num_synapses = 2, \
.ext = quad8_count_ext, \
.num_ext = ARRAY_SIZE(quad8_count_ext) \
}
static struct counter_count quad8_counts[] = {
QUAD8_COUNT(0, "Channel 1 Count"),
QUAD8_COUNT(1, "Channel 2 Count"),
QUAD8_COUNT(2, "Channel 3 Count"),
QUAD8_COUNT(3, "Channel 4 Count"),
QUAD8_COUNT(4, "Channel 5 Count"),
QUAD8_COUNT(5, "Channel 6 Count"),
QUAD8_COUNT(6, "Channel 7 Count"),
QUAD8_COUNT(7, "Channel 8 Count")
};
static irqreturn_t quad8_irq_handler(int irq, void *private)
{
struct counter_device *counter = private;
struct quad8 *const priv = counter_priv(counter);
unsigned int status;
unsigned long irq_status;
unsigned long channel;
unsigned int flg_pins;
u8 event;
int ret;
ret = regmap_read(priv->map, QUAD8_INTERRUPT_STATUS, &status);
if (ret)
return ret;
if (!status)
return IRQ_NONE;
irq_status = status;
for_each_set_bit(channel, &irq_status, QUAD8_NUM_COUNTERS) {
flg_pins = u8_get_bits(priv->ior[channel], FLG_PINS);
switch (flg_pins) {
case FLG1_CARRY_FLG2_BORROW:
event = COUNTER_EVENT_OVERFLOW;
break;
case FLG1_COMPARE_FLG2_BORROW:
event = COUNTER_EVENT_THRESHOLD;
break;
case FLG1_CARRYBORROW_FLG2_UD:
event = COUNTER_EVENT_OVERFLOW_UNDERFLOW;
break;
case FLG1_INDX_FLG2_E:
event = COUNTER_EVENT_INDEX;
break;
default:
/* should never reach this path */
WARN_ONCE(true, "invalid interrupt trigger function %u configured for channel %lu\n",
flg_pins, channel);
continue;
}
counter_push_event(counter, event, channel);
}
ret = regmap_write(priv->map, QUAD8_CHANNEL_OPERATION, CLEAR_PENDING_INTERRUPTS);
if (ret)
return ret;
return IRQ_HANDLED;
}
static int quad8_init_counter(struct quad8 *const priv, const size_t channel)
{
int ret;
ret = quad8_filter_clock_prescaler_set(priv, channel, 0);
if (ret)
return ret;
ret = quad8_preset_register_set(priv, channel, 0);
if (ret)
return ret;
ret = quad8_flag_register_reset(priv, channel);
if (ret)
return ret;
/* Binary encoding; Normal count; non-quadrature mode */
priv->cmr[channel] = SELECT_CMR | BINARY | u8_encode_bits(NORMAL_COUNT, COUNT_MODE) |
u8_encode_bits(NON_QUADRATURE, QUADRATURE_MODE);
ret = regmap_write(priv->map, QUAD8_CONTROL(channel), priv->cmr[channel]);
if (ret)
return ret;
/* Disable A and B inputs; preset on index; FLG1 as Carry */
priv->ior[channel] = SELECT_IOR | DISABLE_AB | u8_encode_bits(LOAD_CNTR, LOAD_PIN) |
u8_encode_bits(FLG1_CARRY_FLG2_BORROW, FLG_PINS);
ret = regmap_write(priv->map, QUAD8_CONTROL(channel), priv->ior[channel]);
if (ret)
return ret;
/* Disable index function; negative index polarity */
priv->idr[channel] = SELECT_IDR | u8_encode_bits(DISABLE_INDEX_MODE, INDEX_MODE) |
u8_encode_bits(NEGATIVE_INDEX_POLARITY, INDEX_POLARITY);
return regmap_write(priv->map, QUAD8_CONTROL(channel), priv->idr[channel]);
}
static int quad8_probe(struct device *dev, unsigned int id)
{
struct counter_device *counter;
struct quad8 *priv;
void __iomem *regs;
unsigned long i;
int ret;
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;
}
counter = devm_counter_alloc(dev, sizeof(*priv));
if (!counter)
return -ENOMEM;
priv = counter_priv(counter);
regs = devm_ioport_map(dev, base[id], QUAD8_EXTENT);
if (!regs)
return -ENOMEM;
priv->map = devm_regmap_init_mmio(dev, regs, &quad8_regmap_config);
if (IS_ERR(priv->map))
return dev_err_probe(dev, PTR_ERR(priv->map),
"Unable to initialize register map\n");
/* Initialize Counter device and driver data */
counter->name = dev_name(dev);
counter->parent = dev;
counter->ops = &quad8_ops;
counter->counts = quad8_counts;
counter->num_counts = ARRAY_SIZE(quad8_counts);
counter->signals = quad8_signals;
counter->num_signals = ARRAY_SIZE(quad8_signals);
spin_lock_init(&priv->lock);
/* Reset Index/Interrupt Register */
ret = regmap_write(priv->map, QUAD8_INDEX_INTERRUPT, 0x00);
if (ret)
return ret;
/* Reset all counters and disable interrupt function */
ret = regmap_write(priv->map, QUAD8_CHANNEL_OPERATION,
RESET_COUNTERS | DISABLE_INTERRUPT_FUNCTION);
if (ret)
return ret;
/* Set initial configuration for all counters */
for (i = 0; i < QUAD8_NUM_COUNTERS; i++) {
ret = quad8_init_counter(priv, i);
if (ret)
return ret;
}
/* Disable Differential Encoder Cable Status for all channels */
ret = regmap_write(priv->map, QUAD8_CABLE_STATUS, GENMASK(7, 0));
if (ret)
return ret;
/* Enable all counters and enable interrupt function */
ret = regmap_write(priv->map, QUAD8_CHANNEL_OPERATION,
ENABLE_COUNTERS | ENABLE_INTERRUPT_FUNCTION);
if (ret)
return ret;
ret = devm_request_irq(&counter->dev, irq[id], quad8_irq_handler,
IRQF_SHARED, counter->name, counter);
if (ret)
return ret;
ret = devm_counter_add(dev, counter);
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to add counter\n");
return 0;
}
static struct isa_driver quad8_driver = {
.probe = quad8_probe,
.driver = {
.name = "104-quad-8"
}
};
module_isa_driver_with_irq(quad8_driver, num_quad8, num_irq);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
MODULE_DESCRIPTION("ACCES 104-QUAD-8 driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(COUNTER);