From abcc6b2943145ae2e17a52632ccab50cd612914c Mon Sep 17 00:00:00 2001 From: Micky Ching Date: Mon, 17 Feb 2014 16:45:47 +0800 Subject: [PATCH] mmc: rtsx: modify phase searching method for tuning The new phase searching method is more concise and easier to understand. Signed-off-by: Micky Ching Signed-off-by: Chris Ball --- drivers/mmc/host/rtsx_pci_sdmmc.c | 112 +++++++++--------------------- include/linux/mfd/rtsx_pci.h | 2 +- 2 files changed, 33 insertions(+), 81 deletions(-) diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c index cc80e3119d1d..0b9ded13a3ae 100644 --- a/drivers/mmc/host/rtsx_pci_sdmmc.c +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c @@ -31,16 +31,6 @@ #include #include -/* SD Tuning Data Structure - * Record continuous timing phase path - */ -struct timing_phase_path { - int start; - int end; - int mid; - int len; -}; - struct realtek_pci_sdmmc { struct platform_device *pdev; struct rtsx_pcr *pcr; @@ -511,85 +501,47 @@ static int sd_change_phase(struct realtek_pci_sdmmc *host, return 0; } -static u8 sd_search_final_phase(struct realtek_pci_sdmmc *host, u32 phase_map) +static inline u32 test_phase_bit(u32 phase_map, unsigned int bit) { - struct timing_phase_path path[MAX_PHASE + 1]; - int i, j, cont_path_cnt; - int new_block, max_len, final_path_idx; - u8 final_phase = 0xFF; + bit %= RTSX_PHASE_MAX; + return phase_map & (1 << bit); +} - /* Parse phase_map, take it as a bit-ring */ - cont_path_cnt = 0; - new_block = 1; - j = 0; - for (i = 0; i < MAX_PHASE + 1; i++) { - if (phase_map & (1 << i)) { - if (new_block) { - new_block = 0; - j = cont_path_cnt++; - path[j].start = i; - path[j].end = i; - } else { - path[j].end = i; - } - } else { - new_block = 1; - if (cont_path_cnt) { - /* Calculate path length and middle point */ - int idx = cont_path_cnt - 1; - path[idx].len = - path[idx].end - path[idx].start + 1; - path[idx].mid = - path[idx].start + path[idx].len / 2; - } - } - } +static int sd_get_phase_len(u32 phase_map, unsigned int start_bit) +{ + int i; - if (cont_path_cnt == 0) { - dev_dbg(sdmmc_dev(host), "No continuous phase path\n"); - goto finish; - } else { - /* Calculate last continuous path length and middle point */ - int idx = cont_path_cnt - 1; - path[idx].len = path[idx].end - path[idx].start + 1; - path[idx].mid = path[idx].start + path[idx].len / 2; + for (i = 0; i < RTSX_PHASE_MAX; i++) { + if (test_phase_bit(phase_map, start_bit + i) == 0) + return i; } + return RTSX_PHASE_MAX; +} + +static u8 sd_search_final_phase(struct realtek_pci_sdmmc *host, u32 phase_map) +{ + int start = 0, len = 0; + int start_final = 0, len_final = 0; + u8 final_phase = 0xFF; - /* Connect the first and last continuous paths if they are adjacent */ - if (!path[0].start && (path[cont_path_cnt - 1].end == MAX_PHASE)) { - /* Using negative index */ - path[0].start = path[cont_path_cnt - 1].start - MAX_PHASE - 1; - path[0].len += path[cont_path_cnt - 1].len; - path[0].mid = path[0].start + path[0].len / 2; - /* Convert negative middle point index to positive one */ - if (path[0].mid < 0) - path[0].mid += MAX_PHASE + 1; - cont_path_cnt--; + if (phase_map == 0) { + dev_err(sdmmc_dev(host), "phase error: [map:%x]\n", phase_map); + return final_phase; } - /* Choose the longest continuous phase path */ - max_len = 0; - final_phase = 0; - final_path_idx = 0; - for (i = 0; i < cont_path_cnt; i++) { - if (path[i].len > max_len) { - max_len = path[i].len; - final_phase = (u8)path[i].mid; - final_path_idx = i; + while (start < RTSX_PHASE_MAX) { + len = sd_get_phase_len(phase_map, start); + if (len_final < len) { + start_final = start; + len_final = len; } - - dev_dbg(sdmmc_dev(host), "path[%d].start = %d\n", - i, path[i].start); - dev_dbg(sdmmc_dev(host), "path[%d].end = %d\n", - i, path[i].end); - dev_dbg(sdmmc_dev(host), "path[%d].len = %d\n", - i, path[i].len); - dev_dbg(sdmmc_dev(host), "path[%d].mid = %d\n", - i, path[i].mid); + start += len ? len : 1; } -finish: - dev_dbg(sdmmc_dev(host), "Final chosen phase: %d\n", final_phase); + final_phase = (start_final + len_final / 2) % RTSX_PHASE_MAX; + dev_dbg(sdmmc_dev(host), "phase: [map:%x] [maxlen:%d] [final:%d]\n", + phase_map, len_final, final_phase); + return final_phase; } @@ -635,7 +587,7 @@ static int sd_tuning_phase(struct realtek_pci_sdmmc *host, int err, i; u32 raw_phase_map = 0; - for (i = MAX_PHASE; i >= 0; i--) { + for (i = 0; i < RTSX_PHASE_MAX; i++) { err = sd_tuning_rx_cmd(host, opcode, (u8)i); if (err == 0) raw_phase_map |= 1 << i; diff --git a/include/linux/mfd/rtsx_pci.h b/include/linux/mfd/rtsx_pci.h index 0ce772105508..a3835976f7c6 100644 --- a/include/linux/mfd/rtsx_pci.h +++ b/include/linux/mfd/rtsx_pci.h @@ -144,7 +144,7 @@ #define HOST_TO_DEVICE 0 #define DEVICE_TO_HOST 1 -#define MAX_PHASE 31 +#define RTSX_PHASE_MAX 32 #define RX_TUNING_CNT 3 /* SG descriptor */ -- 2.30.2