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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
spi: keep track of number of chipselects in spi_device
There are several places where we need to iterate over a device's
chipselect. To be able to do it efficiently, store the number of
chipselects in spi_device, like we do for controllers.
Since we now use a device supplied value, add a check to make sure it
isn't more than we can support.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Link: https://patch.msgid.link/20250915183725.219473-3-jonas.gorski@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
authored by
Jonas Gorski
and committed by
Mark Brown
099f9421
188f6323
+24
-9
+21
-8
drivers/spi/spi.c
+21
-8
drivers/spi/spi.c
···
586
586
spi->dev.bus = &spi_bus_type;
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spi->dev.release = spidev_release;
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spi->mode = ctlr->buswidth_override_bits;
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+
spi->num_chipselect = 1;
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device_initialize(&spi->dev);
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return spi;
···
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u8 idx_new;
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cs = spi_get_chipselect(spi, idx);
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-
for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) {
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+
for (idx_new = new_idx; idx_new < new_spi->num_chipselect; idx_new++) {
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cs_new = spi_get_chipselect(new_spi, idx_new);
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if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) {
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dev_err(dev, "chipselect %u already in use\n", cs_new);
···
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int status, idx;
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if (spi->controller == new_spi->controller) {
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
for (idx = 0; idx < spi->num_chipselect; idx++) {
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status = spi_dev_check_cs(dev, spi, idx, new_spi, 0);
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if (status)
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return status;
···
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int status, idx;
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u8 cs;
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
if (spi->num_chipselect > SPI_CS_CNT_MAX) {
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dev_err(dev, "num_cs %d > max %d\n", spi->num_chipselect,
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+
SPI_CS_CNT_MAX);
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+
return -EOVERFLOW;
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+
}
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+
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+
for (idx = 0; idx < spi->num_chipselect; idx++) {
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/* Chipselects are numbered 0..max; validate. */
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cs = spi_get_chipselect(spi, idx);
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if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) {
···
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* For example, spi->chip_select[0] != spi->chip_select[1] and so on.
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*/
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if (!spi_controller_is_target(ctlr)) {
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
for (idx = 0; idx < spi->num_chipselect; idx++) {
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status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1);
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if (status)
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return status;
···
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if (ctlr->cs_gpiods) {
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u8 cs;
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
for (idx = 0; idx < spi->num_chipselect; idx++) {
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cs = spi_get_chipselect(spi, idx);
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if (is_valid_cs(cs))
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spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]);
···
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/*-------------------------------------------------------------------------*/
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#define spi_for_each_valid_cs(spi, idx) \
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) \
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+
for (idx = 0; idx < spi->num_chipselect; idx++) \
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if (!(spi->cs_index_mask & BIT(idx))) {} else
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static inline bool spi_is_last_cs(struct spi_device *spi)
···
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trace_spi_set_cs(spi, activate);
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spi->controller->last_cs_index_mask = spi->cs_index_mask;
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
1091
-
spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS;
1083
+
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
if (enable && idx < spi->num_chipselect)
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+
spi->controller->last_cs[idx] = spi_get_chipselect(spi, 0);
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+
else
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spi->controller->last_cs[idx] = SPI_INVALID_CS;
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}
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spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
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if (spi->controller->last_cs_mode_high)
···
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dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
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return -EINVAL;
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}
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+
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+
spi->num_chipselect = rc;
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for (idx = 0; idx < rc; idx++)
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spi_set_chipselect(spi, idx, cs[idx]);
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+3
-1
include/linux/spi/spi.h
+3
-1
include/linux/spi/spi.h
···
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* two delays will be added up.
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* @chip_select: Array of physical chipselect, spi->chipselect[i] gives
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* the corresponding physical CS for logical CS i.
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+
* @num_chipselect: Number of physical chipselects used.
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* @cs_index_mask: Bit mask of the active chipselect(s) in the chipselect array
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* @cs_gpiod: Array of GPIO descriptors of the corresponding chipselect lines
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* (optional, NULL when not using a GPIO line)
···
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struct spi_delay cs_inactive;
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u8 chip_select[SPI_CS_CNT_MAX];
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+
u8 num_chipselect;
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/*
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* Bit mask of the chipselect(s) that the driver need to use from
···
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{
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u8 idx;
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-
for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
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+
for (idx = 0; idx < spi->num_chipselect; idx++) {
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if (spi_get_csgpiod(spi, idx))
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return true;
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}