[PATCH] ARM: mxs/mx28evk: add flexcan devices
Sascha Hauer
s.hauer at pengutronix.de
Wed Mar 2 07:09:43 EST 2011
On Wed, Mar 02, 2011 at 07:45:50PM +0800, Shawn Guo wrote:
> On Wed, Mar 02, 2011 at 12:11:48PM +0100, Sascha Hauer wrote:
> > Hi Shawn,
> >
> Hi Sascha,
>
> > On Wed, Mar 02, 2011 at 06:54:44PM +0800, Shawn Guo wrote:
> > > Signed-off-by: Shawn Guo <shawn.guo at freescale.com>
> > > ---
> > > arch/arm/mach-mxs/Kconfig | 1 +
> > > arch/arm/mach-mxs/mach-mx28evk.c | 37 +++++++++++++++++++++++++++++++++++++
> > > 2 files changed, 38 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig
> > > index 55bf075..9a1f2cb 100644
> > > --- a/arch/arm/mach-mxs/Kconfig
> > > +++ b/arch/arm/mach-mxs/Kconfig
> > > @@ -31,6 +31,7 @@ config MACH_MX28EVK
> > > select MXS_HAVE_AMBA_DUART
> > > select MXS_HAVE_PLATFORM_AUART
> > > select MXS_HAVE_PLATFORM_FEC
> > > + select MXS_HAVE_PLATFORM_FLEXCAN
> > > select MXS_OCOTP
> > > default y
> > > help
> > > diff --git a/arch/arm/mach-mxs/mach-mx28evk.c b/arch/arm/mach-mxs/mach-mx28evk.c
> > > index 1f0b708..3cefb73 100644
> > > --- a/arch/arm/mach-mxs/mach-mx28evk.c
> > > +++ b/arch/arm/mach-mxs/mach-mx28evk.c
> > > @@ -28,6 +28,7 @@
> > > #include "devices-mx28.h"
> > > #include "gpio.h"
> > >
> > > +#define MX28EVK_FLEXCAN_SWITCH MXS_GPIO_NR(2, 13)
> > > #define MX28EVK_FEC_PHY_POWER MXS_GPIO_NR(2, 15)
> > > #define MX28EVK_FEC_PHY_RESET MXS_GPIO_NR(4, 13)
> > >
> > > @@ -95,6 +96,15 @@ static const iomux_cfg_t mx28evk_pads[] __initconst = {
> > > /* phy reset line */
> > > MX28_PAD_ENET0_RX_CLK__GPIO_4_13 |
> > > (MXS_PAD_4MA | MXS_PAD_3V3 | MXS_PAD_NOPULL),
> > > +
> > > + /* flexcan0 */
> > > + MX28_PAD_GPMI_RDY2__CAN0_TX,
> > > + MX28_PAD_GPMI_RDY3__CAN0_RX,
> > > + /* flexcan1 */
> > > + MX28_PAD_GPMI_CE2N__CAN1_TX,
> > > + MX28_PAD_GPMI_CE3N__CAN1_RX,
> > > + /* transceiver power control */
> > > + MX28_PAD_SSP1_CMD__GPIO_2_13,
> > > };
> > >
> > > /* fec */
> > > @@ -178,8 +188,28 @@ error:
> > > return -ETIMEDOUT;
> > > }
> > >
> > > +/* flexcan */
> > > +static void mx28evk_flexcan_switch(int enable)
> > > +{
> > > + static int count;
> > > +
> > > + if (enable) {
> > > + if (!count++)
> > > + gpio_set_value(MX28EVK_FLEXCAN_SWITCH, 1);
> > > + } else {
> > > + if (!--count)
> > > + gpio_set_value(MX28EVK_FLEXCAN_SWITCH, 0);
> > > + }
> > > +}
> >
> > Why this count variable? It shouldn't hurt to call gpio_set_value
> > multiple times.
> >
> This gpio controls the power of both flexcan0 and flexcan1
> transceivers, and we do not want one power-off really shut the power
> down if the other is still on.
Ok, I see. You should add a comment making this clear. Or maybe even
better, add a switch function for each controller and do the actual
switching based on "both off" instead of a counter. This even will
work when the flexcan driver has unbalanced switch calls.
Sascha
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