Hi, On Wed, 2015-08-19 at 14:36 +0000, ma...@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, ma...@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 <cl...@altera.com> > > > > Cc: Dinh Nguyen <dingu...@opensource.altera.com> > > > > Cc: Pavel Machek <pa...@denx.de> > > > > Cc: Marek Vasut <ma...@denx.de> > > > > Cc: Wolfgang Denk <w...@denx.de> > > > > Cc: Stefan Roese <s...@denx.de> > > > > Cc: Tom Rini <tr...@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-problem/184410529 > > > > + * 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 am not sure. But definitely we can make the calibration common enough if they required the calibration too. Let wait feedback from Simon. Chin Liang > Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
