@@ -608,6 +608,22 @@ static void spi_dev_set_name(struct spi_device *spi)
spi_get_chipselect(spi, 0));
}
+/*
+ * Zero(0) is a valid physical CS value and can be located at any
+ * logical CS in the spi->chip_select[]. If all the physical CS
+ * are initialized to 0 then It would be difficult to differentiate
+ * between a valid physical CS 0 & an unused logical CS whose physical
+ * CS can be 0. As a solution to this issue initialize all the CS to -1.
+ * Now all the unused logical CS will have -1 physical CS value & can be
+ * ignored while performing physical CS validity checks.
+ */
+#define SPI_INVALID_CS ((s8)-1)
+
+static inline bool is_valid_cs(s8 chip_select)
+{
+ return chip_select != SPI_INVALID_CS;
+}
+
static inline int spi_dev_check_cs(struct device *dev,
struct spi_device *spi, u8 idx,
struct spi_device *new_spi, u8 new_idx)
@@ -618,7 +634,7 @@ static inline int spi_dev_check_cs(struct device *dev,
cs = spi_get_chipselect(spi, idx);
for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) {
cs_new = spi_get_chipselect(new_spi, idx_new);
- if (cs != 0xFF && cs_new != 0xFF && cs == cs_new) {
+ if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) {
dev_err(dev, "chipselect %u already in use\n", cs_new);
return -EBUSY;
}
@@ -658,7 +674,7 @@ static int __spi_add_device(struct spi_device *spi)
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
/* Chipselects are numbered 0..max; validate. */
cs = spi_get_chipselect(spi, idx);
- if (cs != 0xFF && cs >= ctlr->num_chipselect) {
+ if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) {
dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
ctlr->num_chipselect);
return -EINVAL;
@@ -698,7 +714,7 @@ static int __spi_add_device(struct spi_device *spi)
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
cs = spi_get_chipselect(spi, idx);
- if (cs != 0xFF)
+ if (is_valid_cs(cs))
spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]);
}
}
@@ -756,17 +772,8 @@ static void spi_set_all_cs_unused(struct spi_device *spi)
{
u8 idx;
- /*
- * Zero(0) is a valid physical CS value and can be located at any
- * logical CS in the spi->chip_select[]. If all the physical CS
- * are initialized to 0 then It would be difficult to differentiate
- * between a valid physical CS 0 & an unused logical CS whose physical
- * CS can be 0. As a solution to this issue initialize all the CS to 0xFF.
- * Now all the unused logical CS will have 0xFF physical CS value & can be
- * ignore while performing physical CS validity checks.
- */
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
- spi_set_chipselect(spi, idx, 0xFF);
+ spi_set_chipselect(spi, idx, SPI_INVALID_CS);
}
/**
@@ -1021,7 +1028,7 @@ static inline bool spi_is_last_cs(struct spi_device *spi)
bool last = false;
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
- if ((spi->cs_index_mask >> idx) & 0x01) {
+ if (spi->cs_index_mask & BIT(idx)) {
if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx))
last = true;
}
@@ -1050,7 +1057,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
spi->controller->last_cs_index_mask = spi->cs_index_mask;
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
- spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : -1;
+ spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS;
spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
if (spi->mode & SPI_CS_HIGH)
@@ -1072,8 +1079,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
* into account.
*/
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
- if (((spi->cs_index_mask >> idx) & 0x01) &&
- spi_get_csgpiod(spi, idx)) {
+ if ((spi->cs_index_mask & BIT(idx)) && spi_get_csgpiod(spi, idx)) {
if (has_acpi_companion(&spi->dev))
gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
!enable);
@@ -2456,14 +2462,10 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
spi_set_chipselect(spi, idx, cs[idx]);
/*
- * spi->chip_select[i] gives the corresponding physical CS for logical CS i
- * logical CS number is represented by setting the ith bit in spi->cs_index_mask
- * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
- * spi->chip_select[0] will give the physical CS.
- * By default spi->chip_select[0] will hold the physical CS number so, set
- * spi->cs_index_mask as 0x01.
+ * By default spi->chip_select[0] will hold the physical CS number,
+ * so set bit 0 in spi->cs_index_mask.
*/
- spi->cs_index_mask = 0x01;
+ spi->cs_index_mask = BIT(0);
/* Device speed */
if (!of_property_read_u32(nc, "spi-max-frequency", &value))
@@ -2587,14 +2589,10 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
ancillary->max_speed_hz = spi->max_speed_hz;
ancillary->mode = spi->mode;
/*
- * spi->chip_select[i] gives the corresponding physical CS for logical CS i
- * logical CS number is represented by setting the ith bit in spi->cs_index_mask
- * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
- * spi->chip_select[0] will give the physical CS.
- * By default spi->chip_select[0] will hold the physical CS number so, set
- * spi->cs_index_mask as 0x01.
+ * By default spi->chip_select[0] will hold the physical CS number,
+ * so set bit 0 in spi->cs_index_mask.
*/
- ancillary->cs_index_mask = 0x01;
+ ancillary->cs_index_mask = BIT(0);
WARN_ON(!mutex_is_locked(&ctlr->add_lock));
@@ -2841,14 +2839,10 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
spi->irq = lookup.irq;
spi->bits_per_word = lookup.bits_per_word;
/*
- * spi->chip_select[i] gives the corresponding physical CS for logical CS i
- * logical CS number is represented by setting the ith bit in spi->cs_index_mask
- * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and
- * spi->chip_select[0] will give the physical CS.
- * By default spi->chip_select[0] will hold the physical CS number so, set
- * spi->cs_index_mask as 0x01.
+ * By default spi->chip_select[0] will hold the physical CS number,
+ * so set bit 0 in spi->cs_index_mask.
*/
- spi->cs_index_mask = 0x01;
+ spi->cs_index_mask = BIT(0);
return spi;
}
@@ -3346,9 +3340,9 @@ int spi_register_controller(struct spi_controller *ctlr)
goto free_bus_id;
}
- /* Setting last_cs to -1 means no chip selected */
+ /* Setting last_cs to SPI_INVALID_CS means no chip selected */
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
- ctlr->last_cs[idx] = -1;
+ ctlr->last_cs[idx] = SPI_INVALID_CS;
status = device_add(&ctlr->dev);
if (status < 0)
@@ -226,7 +226,8 @@ struct spi_device {
/* The statistics */
struct spi_statistics __percpu *pcpu_statistics;
- /* Bit mask of the chipselect(s) that the driver need to use from
+ /*
+ * Bit mask of the chipselect(s) that the driver need to use from
* the chipselect array.When the controller is capable to handle
* multiple chip selects & memories are connected in parallel
* then more than one bit need to be set in cs_index_mask.
@@ -448,9 +449,11 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* the @cur_msg_completion. This flag is used to signal the context that
* is running spi_finalize_current_message() that it needs to complete()
* @cur_msg_mapped: message has been mapped for DMA
+ * @fallback: fallback to PIO if DMA transfer return failure with
+ * SPI_TRANS_FAIL_NO_START.
+ * @last_cs_mode_high: was (mode & SPI_CS_HIGH) true on the last call to set_cs.
* @last_cs: the last chip_select that is recorded by set_cs, -1 on non chip
* selected
- * @last_cs_mode_high: was (mode & SPI_CS_HIGH) true on the last call to set_cs.
* @xfer_completion: used by core transfer_one_message()
* @busy: message pump is busy
* @running: message pump is running
@@ -527,8 +530,6 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
* If the driver does not set this, the SPI core takes the snapshot as
* close to the driver hand-over as possible.
* @irq_flags: Interrupt enable state during PTP system timestamping
- * @fallback: fallback to PIO if DMA transfer return failure with
- * SPI_TRANS_FAIL_NO_START.
* @queue_empty: signal green light for opportunistically skipping the queue
* for spi_sync transfers.
* @must_async: disable all fast paths in the core
@@ -708,10 +709,10 @@ struct spi_controller {
bool rt;
bool auto_runtime_pm;
bool cur_msg_mapped;
- char last_cs[SPI_CS_CNT_MAX];
- char last_cs_index_mask;
- bool last_cs_mode_high;
bool fallback;
+ bool last_cs_mode_high;
+ s8 last_cs[SPI_CS_CNT_MAX];
+ u32 last_cs_index_mask : SPI_CS_CNT_MAX;
struct completion xfer_completion;
size_t max_dma_len;
There are the following issues with the current code: - inconsistent use of 0xFF and -1 for invalid chip select pin - inconsistent plain or BIT() use - wrong types used for last_cs_* fields - wrong multi-line comment style - misleading or hard-to-understand comments Fix all of these here. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/spi/spi.c | 74 +++++++++++++++++++---------------------- include/linux/spi/spi.h | 15 +++++---- 2 files changed, 42 insertions(+), 47 deletions(-)