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authorMagnus Damm <damm@opensource.se>2011-10-31 17:11:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-31 17:30:54 -0700
commitf59b6f9f323ff1b4567a69f9063cdd8bb57805e6 (patch)
tree5f881aa4e699dbed67455422611038a3d86477d3 /drivers/leds/Kconfig
parent1bff3a2093161d1b982a0958e4eb194bf3c8ce47 (diff)
downloadop-kernel-dev-f59b6f9f323ff1b4567a69f9063cdd8bb57805e6.zip
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leds: Renesas TPU LED driver
Add V2 of the LED driver for a single timer channel for the TPU hardware block commonly found in Renesas SoCs. The driver has been written with optimal Power Management in mind, so to save power the LED is driven as a regular GPIO pin in case of maximum brightness and power off which allows the TPU hardware to be idle and which in turn allows the clocks to be stopped and the power domain to be turned off transparently. Any other brightness level requires use of the TPU hardware in PWM mode. TPU hardware device clocks and power are managed through Runtime PM. System suspend and resume is known to be working - during suspend the LED is set to off by the generic LED code. The TPU hardware timer is equipeed with a 16-bit counter together with an up-to-divide-by-64 prescaler which makes the hardware suitable for brightness control. Hardware blink is unsupported. The LED PWM waveform has been verified with a Fluke 123 Scope meter on a sh7372 Mackerel board. Tested with experimental sh7372 A3SP power domain patches. Platform device bind/unbind tested ok. V2 has been tested on the DS2 LED of the sh73a0-based AG5EVM. [axel.lin@gmail.com: include linux/module.h] Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/leds/Kconfig')
-rw-r--r--drivers/leds/Kconfig12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index dc7caad..ff203a4 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -375,6 +375,18 @@ config LEDS_ASIC3
cannot be used. This driver supports hardware blinking with an on+off
period from 62ms to 125s. Say Y to enable LEDs on the HP iPAQ hx4700.
+config LEDS_RENESAS_TPU
+ bool "LED support for Renesas TPU"
+ depends on LEDS_CLASS && HAVE_CLK && GENERIC_GPIO
+ help
+ This option enables build of the LED TPU platform driver,
+ suitable to drive any TPU channel on newer Renesas SoCs.
+ The driver controls the GPIO pin connected to the LED via
+ the GPIO framework and expects the LED to be connected to
+ a pin that can be driven in both GPIO mode and using TPU
+ pin function. The latter to support brightness control.
+ Brightness control is supported but hardware blinking is not.
+
config LEDS_TRIGGERS
bool "LED Trigger support"
depends on LEDS_CLASS
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