diff options
Diffstat (limited to 'drivers/mmc/host/renesas_sdhi_internal_dmac.c')
| -rw-r--r-- | drivers/mmc/host/renesas_sdhi_internal_dmac.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c new file mode 100644 index 000000000000..a26c6ed8e029 --- /dev/null +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c @@ -0,0 +1,271 @@ +/* + * DMA support for Internal DMAC with SDHI SD/SDIO controller + * + * Copyright (C) 2016-17 Renesas Electronics Corporation + * Copyright (C) 2016-17 Horms Solutions, Simon Horman + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/io-64-nonatomic-hi-lo.h> +#include <linux/mfd/tmio.h> +#include <linux/mmc/host.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/pagemap.h> +#include <linux/scatterlist.h> + +#include "renesas_sdhi.h" +#include "tmio_mmc.h" + +#define DM_CM_DTRAN_MODE 0x820 +#define DM_CM_DTRAN_CTRL 0x828 +#define DM_CM_RST 0x830 +#define DM_CM_INFO1 0x840 +#define DM_CM_INFO1_MASK 0x848 +#define DM_CM_INFO2 0x850 +#define DM_CM_INFO2_MASK 0x858 +#define DM_DTRAN_ADDR 0x880 + +/* DM_CM_DTRAN_MODE */ +#define DTRAN_MODE_CH_NUM_CH0 0 /* "downstream" = for write commands */ +#define DTRAN_MODE_CH_NUM_CH1 BIT(16) /* "uptream" = for read commands */ +#define DTRAN_MODE_BUS_WID_TH (BIT(5) | BIT(4)) +#define DTRAN_MODE_ADDR_MODE BIT(0) /* 1 = Increment address */ + +/* DM_CM_DTRAN_CTRL */ +#define DTRAN_CTRL_DM_START BIT(0) + +/* DM_CM_RST */ +#define RST_DTRANRST1 BIT(9) +#define RST_DTRANRST0 BIT(8) +#define RST_RESERVED_BITS GENMASK_ULL(32, 0) + +/* DM_CM_INFO1 and DM_CM_INFO1_MASK */ +#define INFO1_CLEAR 0 +#define INFO1_DTRANEND1 BIT(17) +#define INFO1_DTRANEND0 BIT(16) + +/* DM_CM_INFO2 and DM_CM_INFO2_MASK */ +#define INFO2_DTRANERR1 BIT(17) +#define INFO2_DTRANERR0 BIT(16) + +/* + * Specification of this driver: + * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma + * - Since this SDHI DMAC register set has 16 but 32-bit width, we + * need a custom accessor. + */ + +/* Definitions for sampling clocks */ +static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = { + { + .clk_rate = 0, + .tap = 0x00000300, + }, +}; + +static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = { + .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE | + TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2, + .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ | + MMC_CAP_CMD23, + .bus_shift = 2, + .scc_offset = 0x1000, + .taps = rcar_gen3_scc_taps, + .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps), + /* Gen3 SDHI DMAC can handle 0xffffffff blk count, but seg = 1 */ + .max_blk_count = 0xffffffff, + .max_segs = 1, +}; + +static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = { + { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, }, + { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, }, + {}, +}; +MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match); + +static void +renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host, + int addr, u64 val) +{ + writeq(val, host->ctl + addr); +} + +static void +renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable) +{ + if (!host->chan_tx || !host->chan_rx) + return; + + if (!enable) + renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1, + INFO1_CLEAR); + + if (host->dma->enable) + host->dma->enable(host, enable); +} + +static void +renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) { + u64 val = RST_DTRANRST1 | RST_DTRANRST0; + + renesas_sdhi_internal_dmac_enable_dma(host, false); + + renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST, + RST_RESERVED_BITS & ~val); + renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST, + RST_RESERVED_BITS | val); + + renesas_sdhi_internal_dmac_enable_dma(host, true); +} + +static void +renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) { + tasklet_schedule(&host->dma_complete); +} + +static void +renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host, + struct mmc_data *data) +{ + struct scatterlist *sg = host->sg_ptr; + u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE; + enum dma_data_direction dir; + int ret; + u32 irq_mask; + + /* This DMAC cannot handle if sg_len is not 1 */ + WARN_ON(host->sg_len > 1); + + /* This DMAC cannot handle if buffer is not 8-bytes alignment */ + if (!IS_ALIGNED(sg->offset, 8)) { + host->force_pio = true; + renesas_sdhi_internal_dmac_enable_dma(host, false); + return; + } + + if (data->flags & MMC_DATA_READ) { + dtran_mode |= DTRAN_MODE_CH_NUM_CH1; + dir = DMA_FROM_DEVICE; + irq_mask = TMIO_STAT_RXRDY; + } else { + dtran_mode |= DTRAN_MODE_CH_NUM_CH0; + dir = DMA_TO_DEVICE; + irq_mask = TMIO_STAT_TXRQ; + } + + ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir); + if (ret < 0) + return; + + renesas_sdhi_internal_dmac_enable_dma(host, true); + + /* disable PIO irqs to avoid "PIO IRQ in DMA mode!" */ + tmio_mmc_disable_mmc_irqs(host, irq_mask); + + /* set dma parameters */ + renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE, + dtran_mode); + renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR, + sg->dma_address); +} + +static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg) +{ + struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; + + tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND); + + /* start the DMAC */ + renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL, + DTRAN_CTRL_DM_START); +} + +static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg) +{ + struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; + enum dma_data_direction dir; + + spin_lock_irq(&host->lock); + + if (!host->data) + goto out; + + if (host->data->flags & MMC_DATA_READ) + dir = DMA_FROM_DEVICE; + else + dir = DMA_TO_DEVICE; + + renesas_sdhi_internal_dmac_enable_dma(host, false); + dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir); + + tmio_mmc_do_data_irq(host); +out: + spin_unlock_irq(&host->lock); +} + +static void +renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host, + struct tmio_mmc_data *pdata) +{ + /* Each value is set to non-zero to assume "enabling" each DMA */ + host->chan_rx = host->chan_tx = (void *)0xdeadbeaf; + + tasklet_init(&host->dma_complete, + renesas_sdhi_internal_dmac_complete_tasklet_fn, + (unsigned long)host); + tasklet_init(&host->dma_issue, + renesas_sdhi_internal_dmac_issue_tasklet_fn, + (unsigned long)host); +} + +static void +renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host) +{ + /* Each value is set to zero to assume "disabling" each DMA */ + host->chan_rx = host->chan_tx = NULL; +} + +static struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = { + .start = renesas_sdhi_internal_dmac_start_dma, + .enable = renesas_sdhi_internal_dmac_enable_dma, + .request = renesas_sdhi_internal_dmac_request_dma, + .release = renesas_sdhi_internal_dmac_release_dma, + .abort = renesas_sdhi_internal_dmac_abort_dma, + .dataend = renesas_sdhi_internal_dmac_dataend_dma, +}; + +static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev) +{ + return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops); +} + +static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend, + tmio_mmc_host_runtime_resume, + NULL) +}; + +static struct platform_driver renesas_internal_dmac_sdhi_driver = { + .driver = { + .name = "renesas_sdhi_internal_dmac", + .pm = &renesas_sdhi_internal_dmac_dev_pm_ops, + .of_match_table = renesas_sdhi_internal_dmac_of_match, + }, + .probe = renesas_sdhi_internal_dmac_probe, + .remove = renesas_sdhi_remove, +}; + +module_platform_driver(renesas_internal_dmac_sdhi_driver); + +MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC"); +MODULE_AUTHOR("Yoshihiro Shimoda"); +MODULE_LICENSE("GPL v2"); |