Use the the tcb counter width to compute the maximum time that can be
represented using the slow clock source instead of the static 16 bit width.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

Clock source changes are never applied to the CMR register.
This may lead to wrong period/duty cycle configuration.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

Some drivers don't set the .owner fields of the struct device_driver or
struct pwm_ops, which causes the module usage count to become wrong.
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.
Signed-off-by: NBoris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: NThierry Reding <thierry.reding@gmail.com>

Add missing .owner of struct pwm_ops. This prevents the module from being
removed from underneath its users.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

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: NBoris BREZILLON <linux-arm@overkiz.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>