diff options
Diffstat (limited to 'Documentation/spi')
-rw-r--r-- | Documentation/spi/spi-summary | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index 761debf748e9..a5ffba33a351 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary | |||
@@ -115,6 +115,9 @@ shows up in sysfs in several locations: | |||
115 | /sys/devices/.../CTLR/spiB.C ... spi_device for on bus "B", | 115 | /sys/devices/.../CTLR/spiB.C ... spi_device for on bus "B", |
116 | chipselect C, accessed through CTLR. | 116 | chipselect C, accessed through CTLR. |
117 | 117 | ||
118 | /sys/devices/.../CTLR/spiB.C/modalias ... identifies the driver | ||
119 | that should be used with this device (for hotplug/coldplug) | ||
120 | |||
118 | /sys/bus/spi/devices/spiB.C ... symlink to the physical | 121 | /sys/bus/spi/devices/spiB.C ... symlink to the physical |
119 | spiB-C device | 122 | spiB-C device |
120 | 123 | ||
@@ -247,6 +250,12 @@ driver is registered: | |||
247 | 250 | ||
248 | Like with other static board-specific setup, you won't unregister those. | 251 | Like with other static board-specific setup, you won't unregister those. |
249 | 252 | ||
253 | The widely used "card" style computers bundle memory, cpu, and little else | ||
254 | onto a card that's maybe just thirty square centimeters. On such systems, | ||
255 | your arch/.../mach-.../board-*.c file would primarily provide information | ||
256 | about the devices on the mainboard into which such a card is plugged. That | ||
257 | certainly includes SPI devices hooked up through the card connectors! | ||
258 | |||
250 | 259 | ||
251 | NON-STATIC CONFIGURATIONS | 260 | NON-STATIC CONFIGURATIONS |
252 | 261 | ||
@@ -258,6 +267,10 @@ up the spi bus master, and will likely need spi_new_device() to provide the | |||
258 | board info based on the board that was hotplugged. Of course, you'd later | 267 | board info based on the board that was hotplugged. Of course, you'd later |
259 | call at least spi_unregister_device() when that board is removed. | 268 | call at least spi_unregister_device() when that board is removed. |
260 | 269 | ||
270 | When Linux includes support for MMC/SD/SDIO/DataFlash cards through SPI, those | ||
271 | configurations will also be dynamic. Fortunately, those devices all support | ||
272 | basic device identification probes, so that support should hotplug normally. | ||
273 | |||
261 | 274 | ||
262 | How do I write an "SPI Protocol Driver"? | 275 | How do I write an "SPI Protocol Driver"? |
263 | ---------------------------------------- | 276 | ---------------------------------------- |