9421bade07
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: Boris BREZILLON <linux-arm@overkiz.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
19 lines
553 B
Plaintext
19 lines
553 B
Plaintext
Atmel TCB PWM controller
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Required properties:
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- compatible: should be "atmel,tcb-pwm"
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- #pwm-cells: Should be 3. The first cell specifies the per-chip index
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of the PWM to use, the second cell is the period in nanoseconds and
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bit 0 in the third cell is used to encode the polarity of PWM output.
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Set bit 0 of the third cell in PWM specifier to 1 for inverse polarity &
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set to 0 for normal polarity.
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- tc-block: The Timer Counter block to use as a PWM chip.
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Example:
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pwm {
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compatible = "atmel,tcb-pwm";
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#pwm-cells = <3>;
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tc-block = <1>;
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};
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