diff options
| author | Seungwon Jeon <tgih.jun@samsung.com> | 2013-08-31 00:13:31 +0900 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2013-09-25 21:34:12 -0400 |
| commit | 1f44a2a55787faa08a50266fa5dc99f0dcd36b7c (patch) | |
| tree | 8f09f1a0e9d5967a20fc409bf3d244a8d3c0d8c1 /drivers/mmc/host/dw_mmc.c | |
| parent | 10b498419f41ffaca7510286c0db8ea34300576d (diff) | |
mmc: dw_mmc: set the supported max/min frequency
Both f_max and f_min will be informed for core layer to request
valid clock rate. But current setting from 'host->bus_hz' may
not represent the max/min frequency properly. Even if host can
actually support high speed than bus_hz, core layer will not
request clock rate over bus_hz. Basically, f_max/f_min can be set
with the values according to spec. And then host will make its best
effort to meet the rate.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/host/dw_mmc.c')
| -rw-r--r-- | drivers/mmc/host/dw_mmc.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index cca9aa6b11c5..50da6e330a15 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -50,6 +50,9 @@ #define DW_MCI_RECV_STATUS 2 #define DW_MCI_DMA_THRESHOLD 16 +#define DW_MCI_FREQ_MAX 200000000 /* unit: HZ */ +#define DW_MCI_FREQ_MIN 400000 /* unit: HZ */ + #ifdef CONFIG_MMC_DW_IDMAC #define IDMAC_INT_CLR (SDMMC_IDMAC_INT_AI | SDMMC_IDMAC_INT_NI | \ SDMMC_IDMAC_INT_CES | SDMMC_IDMAC_INT_DU | \ @@ -1936,6 +1939,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) struct dw_mci_slot *slot; const struct dw_mci_drv_data *drv_data = host->drv_data; int ctrl_id, ret; + u32 freq[2]; u8 bus_width; mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev); @@ -1951,8 +1955,14 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) slot->quirks = dw_mci_of_get_slot_quirks(host->dev, slot->id); mmc->ops = &dw_mci_ops; - mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510); - mmc->f_max = host->bus_hz; + if (of_property_read_u32_array(host->dev->of_node, + "clock-freq-min-max", freq, 2)) { + mmc->f_min = DW_MCI_FREQ_MIN; + mmc->f_max = DW_MCI_FREQ_MAX; + } else { + mmc->f_min = freq[0]; + mmc->f_max = freq[1]; + } if (host->pdata->get_ocr) mmc->ocr_avail = host->pdata->get_ocr(id); |