diff options
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/meson-gx-mmc.c | 161 |
1 files changed, 111 insertions, 50 deletions
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index efffd36c8d77..987bae98c61f 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -49,6 +49,8 @@ #define CLK_TX_DELAY_MASK GENMASK(19, 16) #define CLK_RX_DELAY_MASK GENMASK(23, 20) #define CLK_DELAY_STEP_PS 200 +#define CLK_PHASE_STEP 30 +#define CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP) #define CLK_ALWAYS_ON BIT(24) #define SD_EMMC_DELAY 0x4 @@ -119,12 +121,6 @@ #define MUX_CLK_NUM_PARENTS 2 -struct meson_tuning_params { - unsigned int core_phase; - unsigned int tx_phase; - unsigned int rx_phase; -}; - struct sd_emmc_desc { u32 cmd_cfg; u32 cmd_arg; @@ -155,7 +151,6 @@ struct meson_host { struct sd_emmc_desc *descs; dma_addr_t descs_dma_addr; - struct meson_tuning_params tp; bool vqmmc_enabled; }; @@ -458,13 +453,6 @@ static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios) return 0; } -static void meson_mmc_set_phase_params(struct meson_host *host) -{ - clk_set_phase(host->mmc_clk, host->tp.core_phase); - clk_set_phase(host->tx_clk, host->tp.tx_phase); - clk_set_phase(host->rx_clk, host->tp.rx_phase); -} - /* * The SD/eMMC IP block has an internal mux and divider used for * generating the MMC clock. Use the clock framework to create and @@ -617,18 +605,122 @@ static int meson_mmc_clk_init(struct meson_host *host) if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk))) return PTR_ERR(host->rx_clk); - /* Set the initial phase parameters */ - meson_mmc_set_phase_params(host); - /* init SD_EMMC_CLOCK to sane defaults w/min clock rate */ host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000); ret = clk_set_rate(host->mmc_clk, host->mmc->f_min); if (ret) return ret; + /* + * Set phases : These values are mostly the datasheet recommended ones + * except for the Tx phase. Datasheet recommends 180 but some cards + * fail at initialisation with it. 270 works just fine, it fixes these + * initialisation issues and enable eMMC DDR52 mode. + */ + clk_set_phase(host->mmc_clk, 180); + clk_set_phase(host->tx_clk, 270); + clk_set_phase(host->rx_clk, 0); + return clk_prepare_enable(host->mmc_clk); } +static void meson_mmc_shift_map(unsigned long *map, unsigned long shift) +{ + DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM); + DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM); + + /* + * shift the bitmap right and reintroduce the dropped bits on the left + * of the bitmap + */ + bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM); + bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift, + CLK_PHASE_POINT_NUM); + bitmap_or(map, left, right, CLK_PHASE_POINT_NUM); +} + +static void meson_mmc_find_next_region(unsigned long *map, + unsigned long *start, + unsigned long *stop) +{ + *start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start); + *stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start); +} + +static int meson_mmc_find_tuning_point(unsigned long *test) +{ + unsigned long shift, stop, offset = 0, start = 0, size = 0; + + /* Get the all good/all bad situation out the way */ + if (bitmap_full(test, CLK_PHASE_POINT_NUM)) + return 0; /* All points are good so point 0 will do */ + else if (bitmap_empty(test, CLK_PHASE_POINT_NUM)) + return -EIO; /* No successful tuning point */ + + /* + * Now we know there is a least one region find. Make sure it does + * not wrap by the shifting the bitmap if necessary + */ + shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM); + if (shift != 0) + meson_mmc_shift_map(test, shift); + + while (start < CLK_PHASE_POINT_NUM) { + meson_mmc_find_next_region(test, &start, &stop); + + if ((stop - start) > size) { + offset = start; + size = stop - start; + } + + start = stop; + } + + /* Get the center point of the region */ + offset += (size / 2); + + /* Shift the result back */ + offset = (offset + shift) % CLK_PHASE_POINT_NUM; + + return offset; +} + +static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode, + struct clk *clk) +{ + int point, ret; + DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM); + + dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n", + __clk_get_name(clk)); + bitmap_zero(test, CLK_PHASE_POINT_NUM); + + /* Explore tuning points */ + for (point = 0; point < CLK_PHASE_POINT_NUM; point++) { + clk_set_phase(clk, point * CLK_PHASE_STEP); + ret = mmc_send_tuning(mmc, opcode, NULL); + if (!ret) + set_bit(point, test); + } + + /* Find the optimal tuning point and apply it */ + point = meson_mmc_find_tuning_point(test); + if (point < 0) + return point; /* tuning failed */ + + clk_set_phase(clk, point * CLK_PHASE_STEP); + dev_dbg(mmc_dev(mmc), "success with phase: %d\n", + clk_get_phase(clk)); + return 0; +} + +static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode) +{ + struct meson_host *host = mmc_priv(mmc); + + return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk); +} + static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct meson_host *host = mmc_priv(mmc); @@ -667,6 +759,8 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) host->vqmmc_enabled = true; } + /* Reset rx phase */ + clk_set_phase(host->rx_clk, 0); break; } @@ -989,29 +1083,6 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id) return IRQ_HANDLED; } -static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode) -{ - struct meson_host *host = mmc_priv(mmc); - struct meson_tuning_params tp_old = host->tp; - int ret = -EINVAL, i, cmd_error; - - dev_info(mmc_dev(mmc), "(re)tuning...\n"); - - for (i = 0; i < 360; i += 90) { - host->tp.rx_phase = i; - /* exclude the active parameter set if retuning */ - if (!memcmp(&tp_old, &host->tp, sizeof(tp_old)) && - mmc->doing_retune) - continue; - meson_mmc_set_phase_params(host); - ret = mmc_send_tuning(mmc, opcode, &cmd_error); - if (!ret) - break; - } - - return ret; -} - /* * NOTE: we only need this until the GPIO/pinctrl driver can handle * interrupts. For now, the MMC core will use this for polling. @@ -1156,16 +1227,6 @@ static int meson_mmc_probe(struct platform_device *pdev) if (ret) goto free_host; - /* - * Set phases : These values are mostly the datasheet recommended ones - * except for the Tx phase. Datasheet recommends 180 but some cards - * fail at initialisation with it. 270 works just fine, it fixes these - * initialisation issues and enable eMMC DDR52 mode. - */ - host->tp.core_phase = 180; - host->tp.tx_phase = 270; - host->tp.rx_phase = 0; - ret = meson_mmc_clk_init(host); if (ret) goto err_core_clk; |