From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Date: Wed, 19 Aug 2015 09:26:55 +0200 Subject: [U-Boot] [PATCH 1/2] arm: socfpga: mmc: Enable calibration for drvsel and smpsel In-Reply-To: <1439963690-2523-1-git-send-email-clsee@altera.com> References: <1439963690-2523-1-git-send-email-clsee@altera.com> Message-ID: <20150819072655.GA22240@amd> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed 2015-08-19 00:54:50, 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 > Cc: Dinh Nguyen > Cc: Pavel Machek > Cc: Marek Vasut > Cc: Wolfgang Denk > Cc: Stefan Roese > Cc: Tom Rini > --- > 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 > #include > #include > +#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 Actually, I'd like to see optimized version. It has potential to be easier to read... > + * 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; Codingstyle: "if (" > + /* > + * 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--){ No space before ;. > + /* 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; Create separate functions to make it easier to read and less indented. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html