diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-of-aspeed.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-aspeed.c | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c index b1a14e7dda82..4b30f6a1178e 100644 --- a/drivers/mmc/host/sdhci-of-aspeed.c +++ b/drivers/mmc/host/sdhci-of-aspeed.c @@ -59,6 +59,7 @@ struct aspeed_sdhci_phase_desc { }; struct aspeed_sdhci_pdata { + unsigned int clk_div_start; const struct aspeed_sdhci_phase_desc *phase_desc; size_t nr_phase_descs; }; @@ -200,10 +201,13 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host; unsigned long parent, bus; + struct aspeed_sdhci *sdhci; int div; u16 clk; pltfm_host = sdhci_priv(host); + sdhci = sdhci_pltfm_priv(pltfm_host); + parent = clk_get_rate(pltfm_host->clk); sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL); @@ -214,7 +218,23 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) if (WARN_ON(clock > host->max_clk)) clock = host->max_clk; - for (div = 2; div < 256; div *= 2) { + /* + * Regarding the AST2600: + * + * If (EMMC12C[7:6], EMMC12C[15:8] == 0) then + * period of SDCLK = period of SDMCLK. + * + * If (EMMC12C[7:6], EMMC12C[15:8] != 0) then + * period of SDCLK = period of SDMCLK * 2 * (EMMC12C[7:6], EMMC[15:8]) + * + * If you keep EMMC12C[7:6] = 0 and EMMC12C[15:8] as one-hot, + * 0x1/0x2/0x4/etc, you will find it is compatible to AST2400 or AST2500 + * + * Keep the one-hot behaviour for backwards compatibility except for + * supporting the value 0 in (EMMC12C[7:6], EMMC12C[15:8]), and capture + * the 0-value capability in clk_div_start. + */ + for (div = sdhci->pdata->clk_div_start; div < 256; div *= 2) { bus = parent / div; if (bus <= clock) break; @@ -316,6 +336,10 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) int ret; aspeed_pdata = of_device_get_match_data(&pdev->dev); + if (!aspeed_pdata) { + dev_err(&pdev->dev, "Missing platform configuration data\n"); + return -EINVAL; + } host = sdhci_pltfm_init(pdev, &aspeed_sdhci_pdata, sizeof(*dev)); if (IS_ERR(host)) @@ -334,7 +358,7 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) else if (slot >= 2) return -EINVAL; - if (dev->pdata && slot < dev->pdata->nr_phase_descs) { + if (slot < dev->pdata->nr_phase_descs) { dev->phase_desc = &dev->pdata->phase_desc[slot]; } else { dev_info(&pdev->dev, @@ -396,6 +420,10 @@ static int aspeed_sdhci_remove(struct platform_device *pdev) return 0; } +static const struct aspeed_sdhci_pdata ast2400_sdhci_pdata = { + .clk_div_start = 2, +}; + static const struct aspeed_sdhci_phase_desc ast2600_sdhci_phase[] = { /* SDHCI/Slot 0 */ [0] = { @@ -426,13 +454,14 @@ static const struct aspeed_sdhci_phase_desc ast2600_sdhci_phase[] = { }; static const struct aspeed_sdhci_pdata ast2600_sdhci_pdata = { + .clk_div_start = 1, .phase_desc = ast2600_sdhci_phase, .nr_phase_descs = ARRAY_SIZE(ast2600_sdhci_phase), }; static const struct of_device_id aspeed_sdhci_of_match[] = { - { .compatible = "aspeed,ast2400-sdhci", }, - { .compatible = "aspeed,ast2500-sdhci", }, + { .compatible = "aspeed,ast2400-sdhci", .data = &ast2400_sdhci_pdata, }, + { .compatible = "aspeed,ast2500-sdhci", .data = &ast2400_sdhci_pdata, }, { .compatible = "aspeed,ast2600-sdhci", .data = &ast2600_sdhci_pdata, }, { } }; |