[v5,1/3] counter: 104-quad-8: Add lock guards - generic interface

Message ID	20200316124929.GA389@syed.domain.name (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=e0QT=5B=vger.kernel.org=linux-iio-owner@kernel.org> Date: Mon, 16 Mar 2020 18:19:30 +0530 From: Syed Nayyar Waris <syednwaris@gmail.com> To: vilhelm.gray@gmail.com Cc: jic23@kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 1/3] counter: 104-quad-8: Add lock guards - generic interface Message-ID: <20200316124929.GA389@syed.domain.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-iio-owner@vger.kernel.org Precedence: bulk
Series	[v5,1/3] counter: 104-quad-8: Add lock guards - generic interface \| expand [v5,1/3] counter: 104-quad-8: Add lock guards - generic interface [v5,2/3] counter: 104-quad-8: Add lock guards - differential encoder [v5,3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index 9dab190..dd5faf0 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -44,6 +44,7 @@ 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 fck_prescaler[QUAD8_NUM_COUNTERS]; unsigned int preset[QUAD8_NUM_COUNTERS]; @@ -123,6 +124,8 @@ 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); @@ -130,6 +133,8 @@ 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]; @@ -160,6 +165,8 @@ 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); @@ -183,12 +190,16 @@ 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; @@ -196,11 +207,18 @@ 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) @@ -214,11 +232,15 @@ 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; } @@ -255,6 +277,8 @@ 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 */ @@ -264,6 +288,8 @@ 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; } @@ -293,6 +319,8 @@ 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] | @@ -301,6 +329,8 @@ 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; } @@ -358,6 +388,8 @@ 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 */ @@ -367,6 +399,8 @@ 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; } @@ -394,19 +428,26 @@ 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; } @@ -434,8 +475,12 @@ 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; @@ -453,6 +498,8 @@ 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; } @@ -480,15 +527,20 @@ 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; } @@ -589,7 +641,7 @@ static int quad8_signal_read(struct counter_device *counter, static int quad8_count_read(struct counter_device *counter, struct counter_count *count, unsigned long *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; @@ -603,6 +655,8 @@ static int quad8_count_read(struct counter_device *counter, /* Borrow XOR Carry effectively doubles count range */ *val = (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); @@ -610,13 +664,15 @@ static int quad8_count_read(struct counter_device *counter, for (i = 0; i < 3; i++) *val |= (unsigned long)inb(base_offset) << (8 * i); + mutex_unlock(&priv->lock); + return 0; } static int quad8_count_write(struct counter_device *counter, struct counter_count *count, unsigned long 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 i; @@ -624,6 +680,8 @@ static int quad8_count_write(struct counter_device *counter, if (val > 0xFFFFFF) return -EINVAL; + mutex_lock(&priv->lock); + /* Reset Byte Pointer */ outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); @@ -647,6 +705,8 @@ 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; } @@ -667,13 +727,13 @@ 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; @@ -687,6 +747,8 @@ static int quad8_function_get(struct counter_device *counter, else *function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION; + mutex_unlock(&priv->lock); + return 0; } @@ -697,10 +759,15 @@ 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; @@ -736,6 +803,8 @@ 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; } @@ -852,15 +921,20 @@ 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; } @@ -887,19 +961,26 @@ 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; } @@ -964,6 +1045,8 @@ 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 */ @@ -976,6 +1059,8 @@ 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; } @@ -1017,6 +1102,8 @@ 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; @@ -1024,6 +1111,8 @@ 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; } @@ -1052,14 +1141,28 @@ static ssize_t quad8_count_preset_read(struct counter_device *counter, return sprintf(buf, "%u\n", priv->preset[count->id]); } +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) @@ -1069,14 +1172,11 @@ 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; } @@ -1084,15 +1184,20 @@ 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"); } @@ -1101,15 +1206,29 @@ 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; } @@ -1137,6 +1256,8 @@ 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; @@ -1144,6 +1265,8 @@ 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; } @@ -1429,6 +1552,9 @@ 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 */

[v5,1/3] counter: 104-quad-8: Add lock guards - generic interface

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