On Sun, Sep 04, 2016 at 09:08:27PM +0100, Russell King - ARM Linux wrote:
> On Sun, Sep 04, 2016 at 08:59:46PM +0200, Robert Jarzmik wrote:
> > Add the clock provided to the PCMCIA block so that sa1111_pcmcia_add()
> > doesn't end up on error while probing "1800" device.
>
> I don't think this is correct - SA1111 is not really the PCMCIA
> controller - it's a load of logic which sits between the host
> device and the PCMCIA sockets to manage buffers and the PCMCIA
> socket control signals.
>
> The timing is done by the SoC, and the PCMCIA driver needs a
> clock to compute the timing information for the PCMCIA interface.
> Originally, in 2.6.12-rc2, lubbock (and all of the PXA socket
> drivers) were using pxa2xx_base.c, which got the clock frequency
> via get_memclk_frequency_10khz().
>
> In 2a125dd56b3a ("ARM: pxa: remove get_memclk_frequency_10khz()")
> this was changed to use the clk API, and added the "pxa2xx-pcmcia"
> clock. However, it ignored Lubbock, because that doesn't use
> _that_ device, but the SA1111 PCMCIA sub-device "1800". This commit
> should have introduced an identical entry for the SA1111 PCMCIA
> sub-device.
>
> This is actually one of the problems converting these platforms to
> DT - seemingly simple stuff is actually quite complex because the
> resources are spread around. In the case of Lubbock, some of the
> resources are on the PXA255 SoC, others are on the SA1111 which
> requires a fair amount of initialisation to get to. I think we're
> really into the "combine multiple devices into one logical device"
> game (iow, using the component helper), just like DRM and other
> subsystems.
>
> The quick fix here is to add a clock for the SA1111 PCMCIA sub-device,
> but it still needs to be the SoC memory clock - iow, what
> get_memclk_frequency_10khz() would have returned as that's what
> pxa2xx_base.c wants.
IOW, something like:
arch/arm/mach-pxa/lubbock.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-pxa/lubbock.c b/arch/arm/mach-pxa/lubbock.c
index cd401546cea8..d7c5fb00da7a 100644
--- a/arch/arm/mach-pxa/lubbock.c
+++ b/arch/arm/mach-pxa/lubbock.c
@@ -149,6 +149,20 @@ static struct gpiod_lookup_table sa1111_pcmcia_gpio_table
= {
},
};
+static void lubbock_init_pcmcia(void)
+{
+ struct clk *clk;
+
+ gpiod_add_lookup_table(&sa1111_pcmcia_gpio_table);
+
+ /* Add an alias for the SA1111 PCMCIA clock */
+ clk = clk_get_sys("pxa2xx-pcmcia", NULL);
+ if (!IS_ERR(clk)) {
+ clkdev_create(clk, NULL, "1800");
+ clk_put(clk);
+ }
+}
+
static struct resource sa1111_resources[] = {
[0] = {
.start = 0x10000000,
@@ -488,7 +502,7 @@ static void __init lubbock_init(void)
pxa_set_btuart_info(NULL);
pxa_set_stuart_info(NULL);
- gpiod_add_lookup_table(&sa1111_pcmcia_gpio_table);
+ lubbock_init_pcmcia();
clk_add_alias("SA1111_CLK", NULL, "GPIO11_CLK", NULL);
pxa_set_udc_info(&udc_info);
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
