diff options
| -rw-r--r-- | drivers/mmc/am654_sdhci.c | 107 |
1 files changed, 89 insertions, 18 deletions
diff --git a/drivers/mmc/am654_sdhci.c b/drivers/mmc/am654_sdhci.c index 05719827b4..8ec3285337 100644 --- a/drivers/mmc/am654_sdhci.c +++ b/drivers/mmc/am654_sdhci.c @@ -97,6 +97,7 @@ struct am654_sdhci_plat { u32 strb_sel; u32 clkbuf_sel; u32 flags; + bool dll_enable; #define DLL_PRESENT BIT(0) #define IOMUX_PRESENT BIT(1) #define FREQSEL_2_BIT BIT(2) @@ -110,6 +111,12 @@ struct timing_data { u32 capability; }; +struct window { + u8 start; + u8 end; + u8 length; +}; + static const struct timing_data td[] = { [MMC_LEGACY] = {"ti,otap-del-sel-legacy", "ti,itap-del-sel-legacy", @@ -280,8 +287,11 @@ static int am654_sdhci_set_ios_post(struct sdhci_host *host) ret = am654_sdhci_setup_dll(plat, speed); if (ret) return ret; + + plat->dll_enable = true; } else { am654_sdhci_setup_delay_chain(plat, mode); + plat->dll_enable = false; } regmap_update_bits(plat->base, PHY_CTRL5, CLKBUFSEL_MASK, @@ -375,38 +385,99 @@ static void am654_sdhci_write_b(struct sdhci_host *host, u8 val, int reg) writeb(val, host->ioaddr + reg); } #ifdef MMC_SUPPORTS_TUNING -#define ITAP_MAX 32 +#define ITAPDLY_LENGTH 32 +#define ITAPDLY_LAST_INDEX (ITAPDLY_LENGTH - 1) + +static u32 am654_sdhci_calculate_itap(struct udevice *dev, struct window + *fail_window, u8 num_fails, bool circular_buffer) +{ + u8 itap = 0, start_fail = 0, end_fail = 0, pass_length = 0; + u8 first_fail_start = 0, last_fail_end = 0; + struct window pass_window = {0, 0, 0}; + int prev_fail_end = -1; + u8 i; + + if (!num_fails) + return ITAPDLY_LAST_INDEX >> 1; + + if (fail_window->length == ITAPDLY_LENGTH) { + dev_err(dev, "No passing ITAPDLY, return 0\n"); + return 0; + } + + first_fail_start = fail_window->start; + last_fail_end = fail_window[num_fails - 1].end; + + for (i = 0; i < num_fails; i++) { + start_fail = fail_window[i].start; + end_fail = fail_window[i].end; + pass_length = start_fail - (prev_fail_end + 1); + + if (pass_length > pass_window.length) { + pass_window.start = prev_fail_end + 1; + pass_window.length = pass_length; + } + prev_fail_end = end_fail; + } + + if (!circular_buffer) + pass_length = ITAPDLY_LAST_INDEX - last_fail_end; + else + pass_length = ITAPDLY_LAST_INDEX - last_fail_end + first_fail_start; + + if (pass_length > pass_window.length) { + pass_window.start = last_fail_end + 1; + pass_window.length = pass_length; + } + + if (!circular_buffer) + itap = pass_window.start + (pass_window.length >> 1); + else + itap = (pass_window.start + (pass_window.length >> 1)) % ITAPDLY_LENGTH; + + return (itap > ITAPDLY_LAST_INDEX) ? ITAPDLY_LAST_INDEX >> 1 : itap; +} + static int am654_sdhci_execute_tuning(struct mmc *mmc, u8 opcode) { struct udevice *dev = mmc->dev; struct am654_sdhci_plat *plat = dev_get_plat(dev); - int cur_val, prev_val = 1, fail_len = 0, pass_window = 0, pass_len; - u32 itap; + struct window fail_window[ITAPDLY_LENGTH]; + u8 curr_pass, itap; + u8 fail_index = 0; + u8 prev_pass = 1; + + memset(fail_window, 0, sizeof(fail_window)); /* Enable ITAPDLY */ regmap_update_bits(plat->base, PHY_CTRL4, ITAPDLYENA_MASK, 1 << ITAPDLYENA_SHIFT); - for (itap = 0; itap < ITAP_MAX; itap++) { + for (itap = 0; itap < ITAPDLY_LENGTH; itap++) { am654_sdhci_write_itapdly(plat, itap); - cur_val = !mmc_send_tuning(mmc, opcode, NULL); - if (cur_val && !prev_val) - pass_window = itap; + curr_pass = !mmc_send_tuning(mmc, opcode, NULL); + + if (!curr_pass && prev_pass) + fail_window[fail_index].start = itap; - if (!cur_val) - fail_len++; + if (!curr_pass) { + fail_window[fail_index].end = itap; + fail_window[fail_index].length++; + } - prev_val = cur_val; + if (curr_pass && !prev_pass) + fail_index++; + + prev_pass = curr_pass; } - /* - * Having determined the length of the failing window and start of - * the passing window calculate the length of the passing window and - * set the final value halfway through it considering the range as a - * circular buffer - */ - pass_len = ITAP_MAX - fail_len; - itap = (pass_window + (pass_len >> 1)) % ITAP_MAX; + + if (fail_window[fail_index].length != 0) + fail_index++; + + itap = am654_sdhci_calculate_itap(dev, fail_window, fail_index, + plat->dll_enable); + am654_sdhci_write_itapdly(plat, itap); return 0; |