Commit 9421bade authored by Boris BREZILLON's avatar Boris BREZILLON Committed by Thierry Reding

pwm: atmel: add Timer Counter Block PWM driver

This patch adds a PWM driver based on Atmel Timer Counter Block. The
Timer Counter Block is used in Waveform generator mode.

A Timer Counter Block provides up to 6 PWM devices grouped by 2:
* group 0 = PWM 0 and 1
* group 1 = PWM 2 and 3
* group 2 = PMW 4 and 5

PWM devices in a given group must be configured with the same period
value. If a PWM device in a group tries to change the period value and
the other device is already configured with a different value an error
will be returned.

This driver requires device tree support. The Timer Counter Block number
used to create a PWM chip is given by the tc-block field in an
"atmel,tcb-pwm" compatible node.

This patch was tested on kizbox board (at91sam9g20 SoC) with pwm-leds.
Signed-off-by: default avatarBoris BREZILLON <linux-arm@overkiz.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent d1c3ed66
Atmel TCB PWM controller
Required properties:
- compatible: should be "atmel,tcb-pwm"
- #pwm-cells: Should be 3. The first cell specifies the per-chip index
of the PWM to use, the second cell is the period in nanoseconds and
bit 0 in the third cell is used to encode the polarity of PWM output.
Set bit 0 of the third cell in PWM specifier to 1 for inverse polarity &
set to 0 for normal polarity.
- tc-block: The Timer Counter block to use as a PWM chip.
Example:
pwm {
compatible = "atmel,tcb-pwm";
#pwm-cells = <3>;
tc-block = <1>;
};
...@@ -37,6 +37,18 @@ config PWM_AB8500 ...@@ -37,6 +37,18 @@ config PWM_AB8500
To compile this driver as a module, choose M here: the module To compile this driver as a module, choose M here: the module
will be called pwm-ab8500. will be called pwm-ab8500.
config PWM_ATMEL_TCB
tristate "TC Block PWM"
depends on ATMEL_TCLIB && OF
help
Generic PWM framework driver for Atmel Timer Counter Block.
A Timer Counter Block provides 6 PWM devices grouped by 2.
Devices in a given group must have the same period.
To compile this driver as a module, choose M here: the module
will be called pwm-atmel-tcb.
config PWM_BFIN config PWM_BFIN
tristate "Blackfin PWM support" tristate "Blackfin PWM support"
depends on BFIN_GPTIMERS depends on BFIN_GPTIMERS
......
obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM) += core.o
obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
......
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