pwm: lpc32xx: fixes in the LPC32xx PWM driver

The changeset fixes a number of issues within current implementation of LPC32xx PWM controller driver, namely
- the SoC has two independent PWM controllers with one channel each,
- runtime warnings from common clock framework,
- overflow in duty cycle calculation may result in disabled PWM,
- unsupported period values are not accepted.

Correction of PWM channels requires a correspondent change in arch/arm/boot/dts/lpc32xx.dtsi, it has been already sent for review.

Changes from v1 to v2:
- corrected style of examples in documentation,
- improved commit messages

Version v1 can be found here:
http://comments.gmane.org/gmane.linux.pwm/2828
http://www.spinics.net/lists/devicetree/msg105398.html

Vladimir Zapolskiy (6):
dt: lpc32xx: pwm: correct LPC32xx PWM device node example
dt: lpc32xx: pwm: update documentation of LPC32xx PWM device
pwm: lpc32xx: correct number of PWM channels from 2 to 1
pwm: lpc32xx: fix warnings from common clock framework
pwm: lpc32xx: fix and simplify duty cycle and period calculations
pwm: lpc32xx: return ERANGE, if requested period is not supported

 .../devicetree/bindings/pwm/lpc32xx-pwm.txt        |  9 +++-
 drivers/pwm/pwm-lpc32xx.c                          | 59 ++++++++--------------
 2 files changed, 29 insertions(+), 39 deletions(-)