From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Message-ID: <51F66964.1090803@linaro.org> Date: Mon, 29 Jul 2013 15:08:52 +0200 From: Daniel Lezcano MIME-Version: 1.0 Subject: Re: [PATCH v6 02/20] clocksource: samsung_pwm_timer: Correct definition of AUTORELOAD bit References: <1374278673-25615-1-git-send-email-tomasz.figa@gmail.com> <1658534.7nG6RFjcTc@flatron> <51EDA3EA.9020502@linaro.org> <2416336.ny4L9Sf7Ts@flatron> In-Reply-To: <2416336.ny4L9Sf7Ts@flatron> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit List-ID: To: Tomasz Figa Cc: linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, Kukjin Kim , Arnd Bergmann , Olof Johansson , Sylwester Nawrocki , =?UTF-8?B?SGVpa28gU3TDvGJuZXI=?= , Mark Brown , Thierry Reding On 07/24/2013 01:32 AM, Tomasz Figa wrote: > PWM channel 4 has its autoreload bit located at different position. This > patch fixes the driver to account for that. > > This fixes a problem with the clocksource hanging after it overflows because > it is not reloaded any more. > > Signed-off-by: Tomasz Figa > Reviewed-by: Sylwester Nawrocki > --- Acked-by: Daniel Lezcano > drivers/clocksource/samsung_pwm_timer.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > Changes since v5: > - Added more detailed comment about bit layout in TCON register. > > diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c > index 3fa5b07..5d0049f 100644 > --- a/drivers/clocksource/samsung_pwm_timer.c > +++ b/drivers/clocksource/samsung_pwm_timer.c > @@ -44,10 +44,21 @@ > #define TCFG1_SHIFT(x) ((x) * 4) > #define TCFG1_MUX_MASK 0xf > > +/* > + * Each channel occupies 4 bits in TCON register, but there is a gap of 4 > + * bits (one channel) after channel 0, so channels have different numbering > + * when accessing TCON register. > + * > + * In addition, the location of autoreload bit for channel 4 (TCON channel 5) > + * in its set of bits is 2 as opposed to 3 for other channels. > + */ > #define TCON_START(chan) (1 << (4 * (chan) + 0)) > #define TCON_MANUALUPDATE(chan) (1 << (4 * (chan) + 1)) > #define TCON_INVERT(chan) (1 << (4 * (chan) + 2)) > -#define TCON_AUTORELOAD(chan) (1 << (4 * (chan) + 3)) > +#define _TCON_AUTORELOAD(chan) (1 << (4 * (chan) + 3)) > +#define _TCON_AUTORELOAD4(chan) (1 << (4 * (chan) + 2)) > +#define TCON_AUTORELOAD(chan) \ > + ((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan)) > > DEFINE_SPINLOCK(samsung_pwm_lock); > EXPORT_SYMBOL(samsung_pwm_lock); > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog