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path: root/drivers/spi/spi.c
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Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c275
1 files changed, 153 insertions, 122 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index e353b7a9e54e..c99181165321 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -363,6 +363,10 @@ static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
const struct spi_device *spi = to_spi_device(dev);
int rc;
+ rc = of_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
rc = acpi_device_uevent_modalias(dev, env);
if (rc != -ENODEV)
return rc;
@@ -560,49 +564,23 @@ static void spi_cleanup(struct spi_device *spi)
spi->controller->cleanup(spi);
}
-/**
- * spi_add_device - Add spi_device allocated with spi_alloc_device
- * @spi: spi_device to register
- *
- * Companion function to spi_alloc_device. Devices allocated with
- * spi_alloc_device can be added onto the spi bus with this function.
- *
- * Return: 0 on success; negative errno on failure
- */
-int spi_add_device(struct spi_device *spi)
+static int __spi_add_device(struct spi_device *spi)
{
struct spi_controller *ctlr = spi->controller;
struct device *dev = ctlr->dev.parent;
int status;
- /* Chipselects are numbered 0..max; validate. */
- if (spi->chip_select >= ctlr->num_chipselect) {
- dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
- ctlr->num_chipselect);
- return -EINVAL;
- }
-
- /* Set the bus ID string */
- spi_dev_set_name(spi);
-
- /* We need to make sure there's no other device with this
- * chipselect **BEFORE** we call setup(), else we'll trash
- * its configuration. Lock against concurrent add() calls.
- */
- mutex_lock(&spi_add_lock);
-
status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
if (status) {
dev_err(dev, "chipselect %d already in use\n",
spi->chip_select);
- goto done;
+ return status;
}
/* Controller may unregister concurrently */
if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
!device_is_registered(&ctlr->dev)) {
- status = -ENODEV;
- goto done;
+ return -ENODEV;
}
/* Descriptors take precedence */
@@ -619,7 +597,7 @@ int spi_add_device(struct spi_device *spi)
if (status < 0) {
dev_err(dev, "can't setup %s, status %d\n",
dev_name(&spi->dev), status);
- goto done;
+ return status;
}
/* Device may be bound to an active driver when this returns */
@@ -632,12 +610,64 @@ int spi_add_device(struct spi_device *spi)
dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
}
-done:
+ return status;
+}
+
+/**
+ * spi_add_device - Add spi_device allocated with spi_alloc_device
+ * @spi: spi_device to register
+ *
+ * Companion function to spi_alloc_device. Devices allocated with
+ * spi_alloc_device can be added onto the spi bus with this function.
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int spi_add_device(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct device *dev = ctlr->dev.parent;
+ int status;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi->chip_select >= ctlr->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
+ ctlr->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ spi_dev_set_name(spi);
+
+ /* We need to make sure there's no other device with this
+ * chipselect **BEFORE** we call setup(), else we'll trash
+ * its configuration. Lock against concurrent add() calls.
+ */
+ mutex_lock(&spi_add_lock);
+ status = __spi_add_device(spi);
mutex_unlock(&spi_add_lock);
return status;
}
EXPORT_SYMBOL_GPL(spi_add_device);
+static int spi_add_device_locked(struct spi_device *spi)
+{
+ struct spi_controller *ctlr = spi->controller;
+ struct device *dev = ctlr->dev.parent;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi->chip_select >= ctlr->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
+ ctlr->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ spi_dev_set_name(spi);
+
+ WARN_ON(!mutex_is_locked(&spi_add_lock));
+ return __spi_add_device(spi);
+}
+
/**
* spi_new_device - instantiate one new SPI device
* @ctlr: Controller to which device is connected
@@ -804,6 +834,8 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
(spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
return;
+ trace_spi_set_cs(spi, activate);
+
spi->controller->last_cs_enable = enable;
spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
@@ -961,11 +993,15 @@ static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
if (ctlr->dma_tx)
tx_dev = ctlr->dma_tx->device->dev;
+ else if (ctlr->dma_map_dev)
+ tx_dev = ctlr->dma_map_dev;
else
tx_dev = ctlr->dev.parent;
if (ctlr->dma_rx)
rx_dev = ctlr->dma_rx->device->dev;
+ else if (ctlr->dma_map_dev)
+ rx_dev = ctlr->dma_map_dev;
else
rx_dev = ctlr->dev.parent;
@@ -1132,10 +1168,20 @@ static int spi_transfer_wait(struct spi_controller *ctlr,
if (!speed_hz)
speed_hz = 100000;
- ms = 8LL * 1000LL * xfer->len;
+ /*
+ * For each byte we wait for 8 cycles of the SPI clock.
+ * Since speed is defined in Hz and we want milliseconds,
+ * use respective multiplier, but before the division,
+ * otherwise we may get 0 for short transfers.
+ */
+ ms = 8LL * MSEC_PER_SEC * xfer->len;
do_div(ms, speed_hz);
- ms += ms + 200; /* some tolerance */
+ /*
+ * Increase it twice and add 200 ms tolerance, use
+ * predefined maximum in case of overflow.
+ */
+ ms += ms + 200;
if (ms > UINT_MAX)
ms = UINT_MAX;
@@ -1158,10 +1204,10 @@ static void _spi_transfer_delay_ns(u32 ns)
{
if (!ns)
return;
- if (ns <= 1000) {
+ if (ns <= NSEC_PER_USEC) {
ndelay(ns);
} else {
- u32 us = DIV_ROUND_UP(ns, 1000);
+ u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
if (us <= 10)
udelay(us);
@@ -1181,21 +1227,25 @@ int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
switch (unit) {
case SPI_DELAY_UNIT_USECS:
- delay *= 1000;
+ delay *= NSEC_PER_USEC;
break;
- case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
+ case SPI_DELAY_UNIT_NSECS:
+ /* Nothing to do here */
break;
case SPI_DELAY_UNIT_SCK:
/* clock cycles need to be obtained from spi_transfer */
if (!xfer)
return -EINVAL;
- /* if there is no effective speed know, then approximate
- * by underestimating with half the requested hz
+ /*
+ * If there is unknown effective speed, approximate it
+ * by underestimating with half of the requested hz.
*/
hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
if (!hz)
return -EINVAL;
- delay *= DIV_ROUND_UP(1000000000, hz);
+
+ /* Convert delay to nanoseconds */
+ delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
break;
default:
return -EINVAL;
@@ -1227,6 +1277,7 @@ EXPORT_SYMBOL_GPL(spi_delay_exec);
static void _spi_transfer_cs_change_delay(struct spi_message *msg,
struct spi_transfer *xfer)
{
+ u32 default_delay_ns = 10 * NSEC_PER_USEC;
u32 delay = xfer->cs_change_delay.value;
u32 unit = xfer->cs_change_delay.unit;
int ret;
@@ -1234,16 +1285,16 @@ static void _spi_transfer_cs_change_delay(struct spi_message *msg,
/* return early on "fast" mode - for everything but USECS */
if (!delay) {
if (unit == SPI_DELAY_UNIT_USECS)
- _spi_transfer_delay_ns(10000);
+ _spi_transfer_delay_ns(default_delay_ns);
return;
}
ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
if (ret) {
dev_err_once(&msg->spi->dev,
- "Use of unsupported delay unit %i, using default of 10us\n",
- unit);
- _spi_transfer_delay_ns(10000);
+ "Use of unsupported delay unit %i, using default of %luus\n",
+ unit, default_delay_ns / NSEC_PER_USEC);
+ _spi_transfer_delay_ns(default_delay_ns);
}
}
@@ -2057,6 +2108,7 @@ of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
/* Store a pointer to the node in the device structure */
of_node_get(nc);
spi->dev.of_node = nc;
+ spi->dev.fwnode = of_fwnode_handle(nc);
/* Register the new device */
rc = spi_add_device(spi);
@@ -2104,6 +2156,55 @@ static void of_register_spi_devices(struct spi_controller *ctlr)
static void of_register_spi_devices(struct spi_controller *ctlr) { }
#endif
+/**
+ * spi_new_ancillary_device() - Register ancillary SPI device
+ * @spi: Pointer to the main SPI device registering the ancillary device
+ * @chip_select: Chip Select of the ancillary device
+ *
+ * Register an ancillary SPI device; for example some chips have a chip-select
+ * for normal device usage and another one for setup/firmware upload.
+ *
+ * This may only be called from main SPI device's probe routine.
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
+ u8 chip_select)
+{
+ struct spi_device *ancillary;
+ int rc = 0;
+
+ /* Alloc an spi_device */
+ ancillary = spi_alloc_device(spi->controller);
+ if (!ancillary) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
+
+ /* Use provided chip-select for ancillary device */
+ ancillary->chip_select = chip_select;
+
+ /* Take over SPI mode/speed from SPI main device */
+ ancillary->max_speed_hz = spi->max_speed_hz;
+ ancillary->mode = spi->mode;
+
+ /* Register the new device */
+ rc = spi_add_device_locked(ancillary);
+ if (rc) {
+ dev_err(&spi->dev, "failed to register ancillary device\n");
+ goto err_out;
+ }
+
+ return ancillary;
+
+err_out:
+ spi_dev_put(ancillary);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
+
#ifdef CONFIG_ACPI
struct acpi_spi_lookup {
struct spi_controller *ctlr;
@@ -2621,9 +2722,10 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
native_cs_mask |= BIT(i);
}
- ctlr->unused_native_cs = ffz(native_cs_mask);
- if (num_cs_gpios && ctlr->max_native_cs &&
- ctlr->unused_native_cs >= ctlr->max_native_cs) {
+ ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
+
+ if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
+ ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
dev_err(dev, "No unused native chip select available\n");
return -EINVAL;
}
@@ -3440,8 +3542,10 @@ int spi_setup(struct spi_device *spi)
spi_set_thread_rt(spi->controller);
}
- dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
- (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
+ trace_spi_setup(spi, status);
+
+ dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
+ spi->mode & SPI_MODE_X_MASK,
(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
(spi->mode & SPI_3WIRE) ? "3wire, " : "",
@@ -3453,79 +3557,6 @@ int spi_setup(struct spi_device *spi)
}
EXPORT_SYMBOL_GPL(spi_setup);
-/**
- * spi_set_cs_timing - configure CS setup, hold, and inactive delays
- * @spi: the device that requires specific CS timing configuration
- * @setup: CS setup time specified via @spi_delay
- * @hold: CS hold time specified via @spi_delay
- * @inactive: CS inactive delay between transfers specified via @spi_delay
- *
- * Return: zero on success, else a negative error code.
- */
-int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
- struct spi_delay *hold, struct spi_delay *inactive)
-{
- struct device *parent = spi->controller->dev.parent;
- size_t len;
- int status;
-
- if (spi->controller->set_cs_timing &&
- !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) {
- mutex_lock(&spi->controller->io_mutex);
-
- if (spi->controller->auto_runtime_pm) {
- status = pm_runtime_get_sync(parent);
- if (status < 0) {
- mutex_unlock(&spi->controller->io_mutex);
- pm_runtime_put_noidle(parent);
- dev_err(&spi->controller->dev, "Failed to power device: %d\n",
- status);
- return status;
- }
-
- status = spi->controller->set_cs_timing(spi, setup,
- hold, inactive);
- pm_runtime_mark_last_busy(parent);
- pm_runtime_put_autosuspend(parent);
- } else {
- status = spi->controller->set_cs_timing(spi, setup, hold,
- inactive);
- }
-
- mutex_unlock(&spi->controller->io_mutex);
- return status;
- }
-
- if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
- (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
- (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
- dev_err(&spi->dev,
- "Clock-cycle delays for CS not supported in SW mode\n");
- return -ENOTSUPP;
- }
-
- len = sizeof(struct spi_delay);
-
- /* copy delays to controller */
- if (setup)
- memcpy(&spi->controller->cs_setup, setup, len);
- else
- memset(&spi->controller->cs_setup, 0, len);
-
- if (hold)
- memcpy(&spi->controller->cs_hold, hold, len);
- else
- memset(&spi->controller->cs_hold, 0, len);
-
- if (inactive)
- memcpy(&spi->controller->cs_inactive, inactive, len);
- else
- memset(&spi->controller->cs_inactive, 0, len);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(spi_set_cs_timing);
-
static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
struct spi_device *spi)
{