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counter: 104-quad-8: Add lock guards - generic interface 

commit fc06926226 upstream.

Add lock protection from race conditions to 104-quad-8 counter driver
generic interface code changes. Mutex calls used for protection.

Fixes: f1d8a071d4 ("counter: 104-quad-8: Add Generic Counter interface support")

Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Syed Nayyar Waris 2020-03-16 18:19:30 +05:30 committed by Greg Kroah-Hartman
parent db66fd5fef
commit 1f107e441b
1 changed files with 160 additions and 34 deletions
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194
drivers/counter/104-quad-8.c
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@ -42,6 +42,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
* @base: base port address of the IIO device
*/
struct quad8_iio {
struct mutex lock;
struct counter_device counter;
unsigned int preset[QUAD8_NUM_COUNTERS];
unsigned int count_mode[QUAD8_NUM_COUNTERS];
@ -116,6 +117,8 @@ static int quad8_read_raw(struct iio_dev *indio_dev,
/* Borrow XOR Carry effectively doubles count range */
*val = (borrow ^ carry) << 24;
mutex_lock(&priv->lock);
/* Reset Byte Pointer; transfer Counter to Output Latch */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
base_offset + 1);
@ -123,6 +126,8 @@ static int quad8_read_raw(struct iio_dev *indio_dev,
for (i = 0; i < 3; i++)
*val |= (unsigned int)inb(base_offset) << (8 * i);
mutex_unlock(&priv->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_ENABLE:
*val = priv->ab_enable[chan->channel];
@ -153,6 +158,8 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
if ((unsigned int)val > 0xFFFFFF)
return -EINVAL;
mutex_lock(&priv->lock);
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
@ -176,12 +183,16 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
/* Reset Error flag */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
mutex_unlock(&priv->lock);
return 0;
case IIO_CHAN_INFO_ENABLE:
/* only boolean values accepted */
if (val < 0 || val > 1)
return -EINVAL;
mutex_lock(&priv->lock);
priv->ab_enable[chan->channel] = val;
ior_cfg = val | priv->preset_enable[chan->channel] << 1;
@ -189,11 +200,18 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
/* Load I/O control configuration */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
mutex_unlock(&priv->lock);
return 0;
case IIO_CHAN_INFO_SCALE:
mutex_lock(&priv->lock);
/* Quadrature scaling only available in quadrature mode */
if (!priv->quadrature_mode[chan->channel] && (val2 || val != 1))
if (!priv->quadrature_mode[chan->channel] &&
(val2 || val != 1)) {
mutex_unlock(&priv->lock);
return -EINVAL;
}
/* Only three gain states (1, 0.5, 0.25) */
if (val == 1 && !val2)
@ -207,11 +225,15 @@ static int quad8_write_raw(struct iio_dev *indio_dev,
priv->quadrature_scale[chan->channel] = 2;
break;
default:
mutex_unlock(&priv->lock);
return -EINVAL;
}
else
else {
mutex_unlock(&priv->lock);
return -EINVAL;
}
mutex_unlock(&priv->lock);
return 0;
}
@ -248,6 +270,8 @@ static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
if (preset > 0xFFFFFF)
return -EINVAL;
mutex_lock(&priv->lock);
priv->preset[chan->channel] = preset;
/* Reset Byte Pointer */
@ -257,6 +281,8 @@ static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
for (i = 0; i < 3; i++)
outb(preset >> (8 * i), base_offset);
mutex_unlock(&priv->lock);
return len;
}
@ -286,6 +312,8 @@ static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
/* Preset enable is active low in Input/Output Control register */
preset_enable = !preset_enable;
mutex_lock(&priv->lock);
priv->preset_enable[chan->channel] = preset_enable;
ior_cfg = priv->ab_enable[chan->channel] |
@ -294,6 +322,8 @@ static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
/* Load I/O control configuration to Input / Output Control Register */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
mutex_unlock(&priv->lock);
return len;
}
@ -351,6 +381,8 @@ static int quad8_set_count_mode(struct iio_dev *indio_dev,
unsigned int mode_cfg = cnt_mode << 1;
const int base_offset = priv->base + 2 * chan->channel + 1;
mutex_lock(&priv->lock);
priv->count_mode[chan->channel] = cnt_mode;
/* Add quadrature mode configuration */
@ -360,6 +392,8 @@ static int quad8_set_count_mode(struct iio_dev *indio_dev,
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -387,19 +421,26 @@ 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;
unsigned int idr_cfg = synchronous_mode;
mutex_lock(&priv->lock);
idr_cfg |= priv->index_polarity[chan->channel] << 1;
/* Index function must be non-synchronous in non-quadrature mode */
if (synchronous_mode && !priv->quadrature_mode[chan->channel])
if (synchronous_mode && !priv->quadrature_mode[chan->channel]) {
mutex_unlock(&priv->lock);
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);
mutex_unlock(&priv->lock);
return 0;
}
@ -427,8 +468,12 @@ 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;
unsigned int mode_cfg;
mutex_lock(&priv->lock);
mode_cfg = priv->count_mode[chan->channel] << 1;
if (quadrature_mode)
mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
@ -446,6 +491,8 @@ static int quad8_set_quadrature_mode(struct iio_dev *indio_dev,
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -473,15 +520,20 @@ 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;
unsigned int idr_cfg = index_polarity << 1;
mutex_lock(&priv->lock);
idr_cfg |= priv->synchronous_mode[chan->channel];
priv->index_polarity[chan->channel] = index_polarity;
/* Load Index Control configuration to Index Control Register */
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -585,7 +637,7 @@ static int quad8_signal_read(struct counter_device *counter,
static int quad8_count_read(struct counter_device *counter,
struct counter_count *count, struct counter_count_read_value *val)
{
const struct quad8_iio *const priv = counter->priv;
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
unsigned int flags;
unsigned int borrow;
@ -600,6 +652,8 @@ static int quad8_count_read(struct counter_device *counter,
/* Borrow XOR Carry effectively doubles count range */
position = (unsigned long)(borrow ^ carry) << 24;
mutex_lock(&priv->lock);
/* Reset Byte Pointer; transfer Counter to Output Latch */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
base_offset + 1);
@ -609,13 +663,15 @@ static int quad8_count_read(struct counter_device *counter,
counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &position);
mutex_unlock(&priv->lock);
return 0;
}
static int quad8_count_write(struct counter_device *counter,
struct counter_count *count, struct counter_count_write_value *val)
{
const struct quad8_iio *const priv = counter->priv;
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
int err;
unsigned long position;
@ -630,6 +686,8 @@ static int quad8_count_write(struct counter_device *counter,
if (position > 0xFFFFFF)
return -EINVAL;
mutex_lock(&priv->lock);
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
@ -653,6 +711,8 @@ static int quad8_count_write(struct counter_device *counter,
/* Reset Error flag */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
mutex_unlock(&priv->lock);
return 0;
}
@ -673,13 +733,13 @@ static enum counter_count_function quad8_count_functions_list[] = {
static int quad8_function_get(struct counter_device *counter,
struct counter_count *count, size_t *function)
{
const struct quad8_iio *const priv = counter->priv;
struct quad8_iio *const priv = counter->priv;
const int id = count->id;
const unsigned int quadrature_mode = priv->quadrature_mode[id];
const unsigned int scale = priv->quadrature_scale[id];
if (quadrature_mode)
switch (scale) {
mutex_lock(&priv->lock);
if (priv->quadrature_mode[id])
switch (priv->quadrature_scale[id]) {
case 0:
*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X1;
break;
@ -693,6 +753,8 @@ static int quad8_function_get(struct counter_device *counter,
else
*function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION;
mutex_unlock(&priv->lock);
return 0;
}
@ -703,10 +765,15 @@ static int quad8_function_set(struct counter_device *counter,
const int id = count->id;
unsigned int *const quadrature_mode = priv->quadrature_mode + id;
unsigned int *const scale = priv->quadrature_scale + id;
unsigned int mode_cfg = priv->count_mode[id] << 1;
unsigned int *const synchronous_mode = priv->synchronous_mode + id;
const unsigned int idr_cfg = priv->index_polarity[id] << 1;
const int base_offset = priv->base + 2 * id + 1;
unsigned int mode_cfg;
unsigned int idr_cfg;
mutex_lock(&priv->lock);
mode_cfg = priv->count_mode[id] << 1;
idr_cfg = priv->index_polarity[id] << 1;
if (function == QUAD8_COUNT_FUNCTION_PULSE_DIRECTION) {
*quadrature_mode = 0;
@ -742,6 +809,8 @@ static int quad8_function_set(struct counter_device *counter,
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -858,15 +927,20 @@ static int quad8_index_polarity_set(struct counter_device *counter,
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id - 16;
const unsigned int idr_cfg = priv->synchronous_mode[channel_id] |
index_polarity << 1;
const int base_offset = priv->base + 2 * channel_id + 1;
unsigned int idr_cfg = index_polarity << 1;
mutex_lock(&priv->lock);
idr_cfg |= priv->synchronous_mode[channel_id];
priv->index_polarity[channel_id] = index_polarity;
/* Load Index Control configuration to Index Control Register */
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -893,19 +967,26 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,
{
struct quad8_iio *const priv = counter->priv;
const size_t channel_id = signal->id - 16;
const unsigned int idr_cfg = synchronous_mode |
priv->index_polarity[channel_id] << 1;
const int base_offset = priv->base + 2 * channel_id + 1;
unsigned int idr_cfg = synchronous_mode;
mutex_lock(&priv->lock);
idr_cfg |= priv->index_polarity[channel_id] << 1;
/* Index function must be non-synchronous in non-quadrature mode */
if (synchronous_mode && !priv->quadrature_mode[channel_id])
if (synchronous_mode && !priv->quadrature_mode[channel_id]) {
mutex_unlock(&priv->lock);
return -EINVAL;
}
priv->synchronous_mode[channel_id] = synchronous_mode;
/* Load Index Control configuration to Index Control Register */
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -970,6 +1051,8 @@ static int quad8_count_mode_set(struct counter_device *counter,
break;
}
mutex_lock(&priv->lock);
priv->count_mode[count->id] = cnt_mode;
/* Set count mode configuration value */
@ -982,6 +1065,8 @@ static int quad8_count_mode_set(struct counter_device *counter,
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
mutex_unlock(&priv->lock);
return 0;
}
@ -1023,6 +1108,8 @@ static ssize_t quad8_count_enable_write(struct counter_device *counter,
if (err)
return err;
mutex_lock(&priv->lock);
priv->ab_enable[count->id] = ab_enable;
ior_cfg = ab_enable | priv->preset_enable[count->id] << 1;
@ -1030,6 +1117,8 @@ static ssize_t quad8_count_enable_write(struct counter_device *counter,
/* Load I/O control configuration */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
mutex_unlock(&priv->lock);
return len;
}
@ -1058,14 +1147,28 @@ static ssize_t quad8_count_preset_read(struct counter_device *counter,
return sprintf(buf, "%u\n", priv->preset[count->id]);
}
static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
unsigned int preset)
{
const unsigned int base_offset = quad8iio->base + 2 * id;
int i;
quad8iio->preset[id] = 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);
}
static ssize_t quad8_count_preset_write(struct counter_device *counter,
struct counter_count *count, void *private, const char *buf, size_t len)
{
struct quad8_iio *const priv = counter->priv;
const int base_offset = priv->base + 2 * count->id;
unsigned int preset;
int ret;
int i;
ret = kstrtouint(buf, 0, &preset);
if (ret)
@ -1075,14 +1178,11 @@ static ssize_t quad8_count_preset_write(struct counter_device *counter,
if (preset > 0xFFFFFF)
return -EINVAL;
priv->preset[count->id] = preset;
mutex_lock(&priv->lock);
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
quad8_preset_register_set(priv, count->id, preset);
/* Set Preset Register */
for (i = 0; i < 3; i++)
outb(preset >> (8 * i), base_offset);
mutex_unlock(&priv->lock);
return len;
}
@ -1090,15 +1190,20 @@ static ssize_t quad8_count_preset_write(struct counter_device *counter,
static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
struct counter_count *count, void *private, char *buf)
{
const struct quad8_iio *const priv = counter->priv;
struct quad8_iio *const priv = counter->priv;
mutex_lock(&priv->lock);
/* Range Limit and Modulo-N count modes use preset value as ceiling */
switch (priv->count_mode[count->id]) {
case 1:
case 3:
return quad8_count_preset_read(counter, count, private, buf);
mutex_unlock(&priv->lock);
return sprintf(buf, "%u\n", priv->preset[count->id]);
}
mutex_unlock(&priv->lock);
/* By default 0x1FFFFFF (25 bits unsigned) is maximum count */
return sprintf(buf, "33554431\n");
}
@ -1107,15 +1212,29 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
struct counter_count *count, void *private, const char *buf, size_t len)
{
struct quad8_iio *const priv = counter->priv;
unsigned int ceiling;
int ret;
ret = kstrtouint(buf, 0, &ceiling);
if (ret)
return ret;
/* Only 24-bit values are supported */
if (ceiling > 0xFFFFFF)
return -EINVAL;
mutex_lock(&priv->lock);
/* Range Limit and Modulo-N count modes use preset value as ceiling */
switch (priv->count_mode[count->id]) {
case 1:
case 3:
return quad8_count_preset_write(counter, count, private, buf,
len);
quad8_preset_register_set(priv, count->id, ceiling);
break;
}
mutex_unlock(&priv->lock);
return len;
}
@ -1143,6 +1262,8 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
/* Preset enable is active low in Input/Output Control register */
preset_enable = !preset_enable;
mutex_lock(&priv->lock);
priv->preset_enable[count->id] = preset_enable;
ior_cfg = priv->ab_enable[count->id] | (unsigned int)preset_enable << 1;
@ -1150,6 +1271,8 @@ static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
/* Load I/O control configuration to Input / Output Control Register */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
mutex_unlock(&priv->lock);
return len;
}
@ -1320,6 +1443,9 @@ static int quad8_probe(struct device *dev, unsigned int id)
quad8iio->counter.priv = quad8iio;
quad8iio->base = base[id];
/* Initialize mutex */
mutex_init(&quad8iio->lock);
/* 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 */