[U-Boot] [PATCH 1/2] arm: socfpga: mmc: Enable calibration for drvsel and smpsel

Marek Vasut
2015-09-01T09:01:07Z

On Tuesday, September 01, 2015 at 10:54:06 AM, Chin Liang See wrote:
> On Wed, 2015-08-26 at 01:54 -0500, Chin Liang See wrote:
> > On Wed, 2015-08-26 at 15:14 +0900, Jaehoon Chung wrote:
> > > On 08/26/2015 02:47 PM, Chin Liang See wrote:
> > > > On Wed, 2015-08-26 at 14:29 +0900, Jaehoon Chung wrote:
> > > >> Hi,
> > > >>
> > > >> On 08/25/2015 12:08 PM, Chin Liang See wrote:
> > > >>> On Tue, 2015-08-25 at 11:36 +0900, Jaehoon Chung wrote:
> > > >>>> Hi,
> > > >>>>
> > > >>>> On 08/25/2015 12:04 AM, Chin Liang See wrote:
> > > >>>>> On Fri, 2015-08-21 at 14:52 -0600, Simon Glass wrote:
> > > >>>>>> Hi,
> > > >>>>>>
> > > >>>>>> On 20 August 2015 at 15:55, Dinh Nguyen <dinh.linux@gmail.com>
wrote:
> > > >>>>>>> +CC: Simon Glass
> > > >>>>>>>
> > > >>>>>>> On Thu, Aug 20, 2015 at 12:32 AM, Marek Vasut <marex@denx.de>
wrote:
> > > >>>>>>>> On Thursday, August 20, 2015 at 07:28:02 AM, Chin Liang See
wrote:
> > > >>>>>>>>> Hi,
> > > >>>>>>>>>
> > > >>>>>>>>> On Wed, 2015-08-19 at 14:36 +0000, marex at denx.de wrote:
> > > >>>>>>>>>> On Wednesday, August 19, 2015 at 10:21:17 AM, Chin Liang See
wrote:
> > > >>>>>>>>>>> Hi,
> > > >>>>>>>>>>
> > > >>>>>>>>>> Hi again,
> > > >>>>>>>>>>
> > > >>>>>>>>>>> On Wed, 2015-08-19 at 02:41 +0000, marex at denx.de wrote:
> > > >>>>>>>>>>>> On Wednesday, August 19, 2015 at 07:54:50 AM, Chin Liang See
wrote:
> > > >>>>>>>>>>>>> Enable SDMMC calibration to determine the best setting
> > > >>>>>>>>>>>>> for drvsel and smpsel. It will be triggered whenever
> > > >>>>>>>>>>>>> there is a change of card frequency and bus width. This
> > > >>>>>>>>>>>>> is to ensure reliable transmission between the
> > > >>>>>>>>>>>>> controller and the card.
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> Signed-off-by: Chin Liang See <clsee@altera.com>
> > > >>>>>>>>>>>>> Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
> > > >>>>>>>
> > > >>>>>>> I think there's something wrong with your git scripts, I did
> > > >>>>>>> not get this email.
> > > >>>>>>>
> > > >>>>>>>>>>>>> Cc: Pavel Machek <pavel@denx.de>
> > > >>>>>>>>>>>>> Cc: Marek Vasut <marex@denx.de>
> > > >>>>>>>>>>>>> Cc: Wolfgang Denk <wd@denx.de>
> > > >>>>>>>>>>>>> Cc: Stefan Roese <sr@denx.de>
> > > >>>>>>>>>>>>> Cc: Tom Rini <trini@konsulko.com>
> > > >>>>>>>>>>>>> ---
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> drivers/mmc/socfpga_dw_mmc.c | 187
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> ++++++++++++++++++++++++++++++++++++++++-- 1 files
> > > >>>>>>>>>>>>> changed, 180 insertions(+), 7 deletions(-)
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> diff --git a/drivers/mmc/socfpga_dw_mmc.c
> > > >>>>>>>>>>>>> b/drivers/mmc/socfpga_dw_mmc.c index eb69aed..15e537c
> > > >>>>>>>>>>>>> 100644 --- a/drivers/mmc/socfpga_dw_mmc.c
> > > >>>>>>>>>>>>> +++ b/drivers/mmc/socfpga_dw_mmc.c
> > > >>>>>>>>>>>>> @@ -11,25 +11,140 @@
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> #include <asm/arch/dwmmc.h>
> > > >>>>>>>>>>>>> #include <asm/arch/clock_manager.h>
> > > >>>>>>>>>>>>> #include <asm/arch/system_manager.h>
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> +#include "mmc_private.h"
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> static const struct socfpga_clock_manager
> > > >>>>>>>>>>>>> *clock_manager_base =
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> (void *)SOCFPGA_CLKMGR_ADDRESS;
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> static const struct socfpga_system_manager
> > > >>>>>>>>>>>>> *system_manager_base =
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> (void *)SOCFPGA_SYSMGR_ADDRESS;
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> -static void socfpga_dwmci_clksel(struct dwmci_host
> > > >>>>>>>>>>>>> *host) +#define CAL_ROWS 7
> > > >>>>>>>>>>>>> +#define CAL_COLS 8
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> +/*
> > > >>>>>>>>>>>>> + * This function determines the largest rectangle filled
> > > >>>>>>>>>>>>> with 1's and returns + * the middle. This functon can be
> > > >>>>>>>>>>>>> optimized, for example using the algorithm + * from
> > > >>>>>>>>>>>>> http://www.drdobbs.com/database/the-maximal-rectangle-pro
> > > >>>>>>>>>>>>> blem/18441 0529 + * It currently takes less than 1ms,
> > > >>>>>>>>>>>>> while creating the input data takes ~5ms + * so there is
> > > >>>>>>>>>>>>> not a real need to optimize it. + */
> > > >>>>>>>>>>>>> +int find_calibration_point(unsigned char
> > > >>>>>>>>>>>>> cal_results[CAL_ROWS][CAL_COLS], +unsigned int sum,
> > > >>>>>>>>>>>>> unsigned int * cal_row, unsigned int * cal_col)
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> {
> > > >>>>>>>>>>>>>
> > > >>>>>>>>>>>>> - unsigned int drvsel;
> > > >>>>>>>>>>>>> - unsigned int smplsel;
> > > >>>>>>>>>>>>> + /* Structure containing a rectangle candidate */
> > > >>>>>>>>>>>>> + typedef struct
> > > >>>>>>>>>>>>> + {
> > > >>>>>>>>>>>>> + unsigned char height;
> > > >>>>>>>>>>>>> + unsigned char width;
> > > >>>>>>>>>>>>> + unsigned short area;
> > > >>>>>>>>>>>>> + } rect_cand_t;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* Array with the rectangle candidates */
> > > >>>>>>>>>>>>> + rect_cand_t rect_cands[CAL_ROWS * CAL_COLS];
> > > >>>>>>>>>>>>> + unsigned char cr_rect_cand = 0;
> > > >>>>>>>>>>>>> + unsigned char height, width, k;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* No solution if all combinations fail */
> > > >>>>>>>>>>>>> + if(sum == 0)
> > > >>>>>>>>>>>>> + return 1;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* Simple solution if all combinations pass */
> > > >>>>>>>>>>>>> + if(sum == (CAL_ROWS * CAL_COLS)) {
> > > >>>>>>>>>>>>> + *cal_row = (CAL_ROWS - 1) / 2;
> > > >>>>>>>>>>>>> + *cal_col = (CAL_COLS - 1) / 2;
> > > >>>>>>>>>>>>> + return 0;
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /*
> > > >>>>>>>>>>>>> + * Create list of all possible sub-rectangles, in
> > > >>>>>>>>>>>>> descending
> > > >>>>>>>>
> > > >>>>>>>> area
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + * order
> > > >>>>>>>>>>>>> + */
> > > >>>>>>>>>>>>> + for(height = CAL_ROWS; height >= 1; height--) {
> > > >>>>>>>>>>>>> + for(width = CAL_COLS; width >= 1 ;
> > > >>>>>>>>>>>>> width--){ + /* Add a new rectangle
> > > >>>>>>>>>>>>> candidate */ +
> > > >>>>>>>>>>>>> rect_cands[cr_rect_cand].height = height; +
> > > >>>>>>>>>>>>> rect_cands[cr_rect_cand].width = width; +
> > > >>>>>>>>>>>>> rect_cands[cr_rect_cand].area = height *
> > > >>>>>>>>>>>>> width; + cr_rect_cand++;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* First candidate it always in the
> > > >>>>>>>>>>>>> right
> > > >>>>>>>>
> > > >>>>>>>> position */
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + if(cr_rect_cand == 1)
> > > >>>>>>>>>>>>> + continue;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /*
> > > >>>>>>>>>>>>> + * Put the candidate in right
> > > >>>>>>>>>>>>> location to
> > > >>>>>>>>
> > > >>>>>>>> maintain
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + * descending order
> > > >>>>>>>>>>>>> + */
> > > >>>>>>>>>>>>> + for(k = cr_rect_cand - 1; k > 1;
> > > >>>>>>>>>>>>> k--){ +
> > > >>>>>>>>>>>>> if(rect_cands[k-1].area <
> > > >>>>>>>>
> > > >>>>>>>> rect_cands[k].area){
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + rect_cand_t tmp =
> > > >>>>>>>>
> > > >>>>>>>> rect_cands[k-1];
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + rect_cands[k-1] =
> > > >>>>>>>>>>>>> rect_cands[k]; +
> > > >>>>>>>>>>>>> rect_cands[k] = tmp; + }
> > > >>>>>>>>>>>>> else
> > > >>>>>>>>>>>>> + break;
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* Try to fit the rectangle candidates, in
> > > >>>>>>>>>>>>> descending area order */ + for(k = 0; k < CAL_ROWS *
> > > >>>>>>>>>>>>> CAL_COLS; k++) { + unsigned char start_row,
> > > >>>>>>>>>>>>> start_col; + unsigned rect_width =
> > > >>>>>>>>>>>>> rect_cands[k].width; + unsigned rect_height
> > > >>>>>>>>>>>>> = rect_cands[k].height; +
> > > >>>>>>>>>>>>> + /* Find the row and column where the
> > > >>>>>>>>>>>>> candidate fits */ + for (start_col = 0;
> > > >>>>>>>>>>>>> start_col < (CAL_COLS - rect_width +
> > > >>>>>>>>
> > > >>>>>>>> 1);
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + start_col++) {
> > > >>>>>>>>>>>>> + for (start_row = 0; start_row <
> > > >>>>>>>>>>>>> (CAL_ROWS - + rect_height + 1);
> > > >>>>>>>>>>>>> start_row++) { + unsigned ok
> > > >>>>>>>>>>>>> = 1;
> > > >>>>>>>>>>>>> + unsigned add_col, add_row;
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* Determine if the
> > > >>>>>>>>>>>>> rectangle fits here
> > > >>>>>>>>
> > > >>>>>>>> */
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + for (add_col = 0; (add_col
> > > >>>>>>>>>>>>> < rect_width)
> > > >>>>>>>>
> > > >>>>>>>> && ok;
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + add_col++) {
> > > >>>>>>>>>>>>> + for (add_row = 0;
> > > >>>>>>>>>>>>> add_row <
> > > >>>>>>>>
> > > >>>>>>>> rect_height;
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + add_row++) {
> > > >>>>>>>>>>>>> + if
> > > >>>>>>>>>>>>> (!cal_results +
> > > >>>>>>>>>>>>> [start_row+add_row]
> > > >>>>>>>>
> > > >>>>>>>> [start_col
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + +
> > > >>>>>>>>>>>>> add_col]) { +
> > > >>>>>>>>>>>>> ok = 0; +
> > > >>>>>>>>>>>>> break; +
> > > >>>>>>>>>>>>> }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /*
> > > >>>>>>>>>>>>> + * Return 'middle' of
> > > >>>>>>>>>>>>> rectangle in case
> > > >>>>>>>>
> > > >>>>>>>> of
> > > >>>>>>>>
> > > >>>>>>>>>>>>> + * success
> > > >>>>>>>>>>>>> + */
> > > >>>>>>>>>>>>> + if (ok) {
> > > >>>>>>>>>>>>> + if(rect_width > 1)
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> rect_width--; +
> > > >>>>>>>>>>>>> + if(rect_height > 1)
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> rect_height--; +
> > > >>>>>>>>>>>>> + *cal_row =
> > > >>>>>>>>>>>>> start_row + +
> > > >>>>>>>>>>>>> (rect_height / 2); +
> > > >>>>>>>>>>>>> *cal_col = start_col +
> > > >>>>>>>>
> > > >>>>>>>> (rect_width / 2);
> > > >>>>>>>>
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + return 0;
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> + }
> > > >>>>>>>>>>>>> +
> > > >>>>>>>>>>>>> + /* We could not fit any rectangle - return failure
> > > >>>>>>>>>>>>> */ + return 1;
> > > >>>>>>>>>>>>
> > > >>>>>>>>>>>> Oh btw. please make sure to use errno.h and standard
> > > >>>>>>>>>>>> return codes ; -EINVAL in this case I believe.
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> Good suggestion, will fix in v2.
> > > >>>>>>>>>>> Thanks
> > > >>>>>>>>>>
> > > >>>>>>>>>> Thanks. I was curious, is this really socfpga specific or
> > > >>>>>>>>>> can this calibration be used on dwmmc in general -- thus on
> > > >>>>>>>>>> exynos and rockchip systems -- as well? If it's generic to
> > > >>>>>>>>>> dwmmc, this should be moved into the dwmmc core code. Also,
> > > >>>>>>>>>> I am CCing Simon, he's been plumbing in the DWMMC recently.
> > > >>>>>>>
> > > >>>>>>> I didn't see you explicitly add Simon to the thread. Doing it
> > > >>>>>>> here..
> > > >>>>>>
> > > >>>>>> One option is to put the function in the common dw_mmc.c file
> > > >>>>>> but have it be called explicitly by drivers that want it (e.g.
> > > >>>>>> for now, just socfpga). The code you have written does look
> > > >>>>>> generic and perhaps should be used on other platforms,
> > > >>>>>>
> > > >>>>>>>>> I am not sure. But definitely we can make the calibration
> > > >>>>>>>>> common enough if they required the calibration too. Let wait
> > > >>>>>>>>> feedback from Simon.
> > > >>>>>>>
> > > >>>>>>> I know that the linux driver for the DW MMC for SoCFGPA,
> > > >>>>>>> Exynos and Rockchip are using the drvsel and smpsel
> > > >>>>>>> parameters. But I also think these parameters can
> > > >>>>>>> be different for different types of SD card. Are you sure this
> > > >>>>>>> function will cover those
> > > >>>>>>> cases?
> > > >>>>>>
> > > >>>>>> Not at all, but perhaps that is something we will find out in
> > > >>>>>> the future.
> > > >>>>>
> > > >>>>> Thanks Simon.
> > > >>>>>
> > > >>>>> I further checked today and noticed Exynos is setting up the
> > > >>>>> clksel (sample clock and drive clock). But from exynos_dw_mmc.c,
> > > >>>>> the value is coming from device tree. So I am notifying Jaehoon
> > > >>>>> wonder the calibration might applicable for him.
> > > >>
> > > >> I think this patch should not be common code at all.
> > > >> Of course, it seems that find_calibration_point function can be used
> > > >> at exynos. But it's too complex and not readable.
> > > >>
> > > >> And smpclk and drvsel are also not common.
> > > >> Depending on SoC, finding approach should be differed.
> > > >> I don't know how smpclk and drvsel controlled, since i don't read
> > > >> TRM of other SoC.
> > > >>
> > > >> Does it need to find the best clksmpl and drvsel value in
> > > >> bootloader?
> > > >
> > > > Yah, its little complex as we try to find the best value for 2
> > > > parameters together. Its also due to the nature that we rely on full
> > > > complete transaction cycle to determine pass or fail (drvsel for out
> > > > while clksmp for in).
> > >
> > > In my experiment, spmlclk value is more important than drvsel.
> > > Anyway, CAL_ROWS and CAL_COLS are candiates, right?
> >
> > Yup, they are representing the value permutation for smplclk and drvsel.
> >
> > > If it can be passed by parameter from each SoC dwmmc controller, that
> > > function should be located into dwmmc.c. Because drvsel and smplclk
> > > bits should be difference at each SoC specific register or Generic
> > > dwmmc(UHS_REG_EXT regster).
> > >
> > > Do you have the plan that change the more generic code than now?
> >
> > Actually I look back and different SoC have different register location
> > for drvsel and smplclk. They are not located within dwmmc controller
> > registers. As of now, they are configure within the callback function of
> > clksel, I believe that should good.
>
> For this case, I presume the change would applicable for socfpga only
> instead common dw_mmc. If everyone agreed, I shall send in new revision
> of the patch.

I'm not very convinced that this should be outside of the dw_mmc core.