diff options
Diffstat (limited to 'drivers/mmc/host/meson-gx-mmc.c')
| -rw-r--r-- | drivers/mmc/host/meson-gx-mmc.c | 85 |
1 files changed, 56 insertions, 29 deletions
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 5582561586b4..037311db3551 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -1,22 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Amlogic SD/eMMC driver for the GX/S905 family SoCs * * Copyright (c) 2016 BayLibre, SAS. * Author: Kevin Hilman <khilman@baylibre.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of version 2 of the GNU General Public License as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. - * The full GNU General Public License is included in this distribution - * in the file called COPYING. */ #include <linux/kernel.h> #include <linux/module.h> @@ -129,6 +116,9 @@ #define SD_EMMC_TXD 0x94 #define SD_EMMC_LAST_REG SD_EMMC_TXD +#define SD_EMMC_SRAM_DATA_BUF_LEN 1536 +#define SD_EMMC_SRAM_DATA_BUF_OFF 0x200 + #define SD_EMMC_CFG_BLK_SIZE 512 /* internal buffer max: 512 bytes */ #define SD_EMMC_CFG_RESP_TIMEOUT 256 /* in clock cycles */ #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */ @@ -168,6 +158,8 @@ struct meson_host { unsigned long req_rate; bool ddr; + bool dram_access_quirk; + struct pinctrl *pinctrl; struct pinctrl_state *pins_default; struct pinctrl_state *pins_clk_gate; @@ -232,12 +224,21 @@ static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd) static void meson_mmc_get_transfer_mode(struct mmc_host *mmc, struct mmc_request *mrq) { + struct meson_host *host = mmc_priv(mmc); struct mmc_data *data = mrq->data; struct scatterlist *sg; int i; bool use_desc_chain_mode = true; /* + * When Controller DMA cannot directly access DDR memory, disable + * support for Chain Mode to directly use the internal SRAM using + * the bounce buffer mode. + */ + if (host->dram_access_quirk) + return; + + /* * Broken SDIO with AP6255-based WiFi on Khadas VIM Pro has been * reported. For some strange reason this occurs in descriptor * chain mode only. So let's fall back to bounce buffer mode @@ -1049,6 +1050,10 @@ static int meson_mmc_probe(struct platform_device *pdev) host->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, host); + /* The G12A SDIO Controller needs an SRAM bounce buffer */ + host->dram_access_quirk = device_property_read_bool(&pdev->dev, + "amlogic,dram-access-quirk"); + /* Get regulators and the supported OCR mask */ host->vqmmc_enabled = false; ret = mmc_regulator_get_supply(mmc); @@ -1146,9 +1151,16 @@ static int meson_mmc_probe(struct platform_device *pdev) goto err_init_clk; mmc->caps |= MMC_CAP_CMD23; - mmc->max_blk_count = CMD_CFG_LENGTH_MASK; + if (host->dram_access_quirk) { + /* Limit to the available sram memory */ + mmc->max_segs = SD_EMMC_SRAM_DATA_BUF_LEN / mmc->max_blk_size; + mmc->max_blk_count = mmc->max_segs; + } else { + mmc->max_blk_count = CMD_CFG_LENGTH_MASK; + mmc->max_segs = SD_EMMC_DESC_BUF_LEN / + sizeof(struct sd_emmc_desc); + } mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size; - mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc); mmc->max_seg_size = mmc->max_req_size; /* @@ -1158,15 +1170,27 @@ static int meson_mmc_probe(struct platform_device *pdev) */ mmc->caps2 &= ~MMC_CAP2_HS400; - /* data bounce buffer */ - host->bounce_buf_size = mmc->max_req_size; - host->bounce_buf = - dma_alloc_coherent(host->dev, host->bounce_buf_size, - &host->bounce_dma_addr, GFP_KERNEL); - if (host->bounce_buf == NULL) { - dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n"); - ret = -ENOMEM; - goto err_free_irq; + if (host->dram_access_quirk) { + /* + * The MMC Controller embeds 1,5KiB of internal SRAM + * that can be used to be used as bounce buffer. + * In the case of the G12A SDIO controller, use these + * instead of the DDR memory + */ + host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN; + host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF; + host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF; + } else { + /* data bounce buffer */ + host->bounce_buf_size = mmc->max_req_size; + host->bounce_buf = + dma_alloc_coherent(host->dev, host->bounce_buf_size, + &host->bounce_dma_addr, GFP_KERNEL); + if (host->bounce_buf == NULL) { + dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n"); + ret = -ENOMEM; + goto err_free_irq; + } } host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN, @@ -1183,8 +1207,9 @@ static int meson_mmc_probe(struct platform_device *pdev) return 0; err_bounce_buf: - dma_free_coherent(host->dev, host->bounce_buf_size, - host->bounce_buf, host->bounce_dma_addr); + if (!host->dram_access_quirk) + dma_free_coherent(host->dev, host->bounce_buf_size, + host->bounce_buf, host->bounce_dma_addr); err_free_irq: free_irq(host->irq, host); err_init_clk: @@ -1208,8 +1233,10 @@ static int meson_mmc_remove(struct platform_device *pdev) dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN, host->descs, host->descs_dma_addr); - dma_free_coherent(host->dev, host->bounce_buf_size, - host->bounce_buf, host->bounce_dma_addr); + + if (!host->dram_access_quirk) + dma_free_coherent(host->dev, host->bounce_buf_size, + host->bounce_buf, host->bounce_dma_addr); clk_disable_unprepare(host->mmc_clk); clk_disable_unprepare(host->core_clk); |