Hi Stefano,
On 14/08/2012 22:33, Benoît Thébaudeau wrote:
Each eSDHC instance has a dedicated clock.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Stefano Babic sbabic@denx.de
Hi Benoît,
.../arch/arm/cpu/arm1136/mx35/generic.c | 14 ++++++++++++-- .../arch/arm/include/asm/arch-mx35/clock.h | 4 +++- 2 files changed, 15 insertions(+), 3 deletions(-)
diff --git u-boot-4d3c95f.orig/arch/arm/cpu/arm1136/mx35/generic.c u-boot-4d3c95f/arch/arm/cpu/arm1136/mx35/generic.c index 4af052c..15a0098 100644 --- u-boot-4d3c95f.orig/arch/arm/cpu/arm1136/mx35/generic.c +++ u-boot-4d3c95f/arch/arm/cpu/arm1136/mx35/generic.c @@ -368,8 +368,12 @@ unsigned int mxc_get_clock(enum mxc_clock clk) return get_ipg_per_clk(); case MXC_UART_CLK: return imx_get_uartclk();
- case MXC_ESDHC_CLK:
- case MXC_ESDHC1_CLK: return mxc_get_peri_clock(ESDHC1_CLK);
- case MXC_ESDHC2_CLK:
return mxc_get_peri_clock(ESDHC2_CLK);- case MXC_ESDHC3_CLK:
return mxc_get_peri_clock(ESDHC3_CLK);Your change let understand that we can have different clocks among the ESDHC controllers.
Indeed.
One thing is not clear to me is that the MX35 have two ESDHC controllers, and you define here a thitd one. Where is it ?
No, there are 3. See the reference manual. It's referenced in the memory map, in the interrupts, in the pin multiplexing and in the clocks.
Even if the two controllers can have different clocks, this is not supported by the driver. In fact, in drivers/mmc/fsl_esdhc.c:
int sdhc_clk = gd->sdhc_clk;
The driver uses always the same clock, stored in the global structure. Before extending the code as in this patch, the driver should be modified to handle separate clocks. Currently the driver supports multiple controller, but they share the same clock or at least the same frequency.
Indeed, I had seen that. I didn't know what to decide as to the driver clocks, so I made this change to select the correct clock if a single clock or frequency is used.
If several clock frequencies are to be supported at once, what kind of API would you like? gd->sdhc_clk could be changed to an array, then the corresponding index could be passed to the init function through the fsl_esdhc_cfg struct.
Best regards, Benoît