--- /dev/null
+/*
+ * 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");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff