sudmac: add support for SUDMAC

Some Renesas USB modules have SUDMAC. This patch supports it using
the shdma-base driver.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sh/Kconfig

@@ -16,3 +16,9 @@ config SH_DMAE
 	depends on SH_DMAE_BASE
 	help
 	  Enable support for the Renesas SuperH DMA controllers.
+
+config SUDMAC
+	tristate "Renesas SUDMAC support"
+	depends on SH_DMAE_BASE
+	help
+	  Enable support for the Renesas SUDMAC controllers.

drivers/dma/sh/Makefile

@@ -1,2 +1,3 @@
 obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o
 obj-$(CONFIG_SH_DMAE) += shdma.o
+obj-$(CONFIG_SUDMAC) += sudmac.o

drivers/dma/sh/sudmac.c

@@ -0,0 +1,428 @@
+/*
+ * Renesas SUDMAC support
+ *
+ * Copyright (C) 2013 Renesas Solutions Corp.
+ *
+ * based on drivers/dma/sh/shdma.c:
+ * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
+ * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
+ * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * This 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/platform_device.h>
+#include <linux/sudmac.h>
+
+struct sudmac_chan {
+	struct shdma_chan shdma_chan;
+	void __iomem *base;
+	char dev_id[16];	/* unique name per DMAC of channel */
+
+	u32 offset;		/* for CFG, BA, BBC, CA, CBC, DEN */
+	u32 cfg;
+	u32 dint_end_bit;
+};
+
+struct sudmac_device {
+	struct shdma_dev shdma_dev;
+	struct sudmac_pdata *pdata;
+	void __iomem *chan_reg;
+};
+
+struct sudmac_regs {
+	u32 base_addr;
+	u32 base_byte_count;
+};
+
+struct sudmac_desc {
+	struct sudmac_regs hw;
+	struct shdma_desc shdma_desc;
+};
+
+#define to_chan(schan) container_of(schan, struct sudmac_chan, shdma_chan)
+#define to_desc(sdesc) container_of(sdesc, struct sudmac_desc, shdma_desc)
+#define to_sdev(sc) container_of(sc->shdma_chan.dma_chan.device, \
+				 struct sudmac_device, shdma_dev.dma_dev)
+
+/* SUDMAC register */
+#define SUDMAC_CH0CFG		0x00
+#define SUDMAC_CH0BA		0x10
+#define SUDMAC_CH0BBC		0x18
+#define SUDMAC_CH0CA		0x20
+#define SUDMAC_CH0CBC		0x28
+#define SUDMAC_CH0DEN		0x30
+#define SUDMAC_DSTSCLR		0x38
+#define SUDMAC_DBUFCTRL		0x3C
+#define SUDMAC_DINTCTRL		0x40
+#define SUDMAC_DINTSTS		0x44
+#define SUDMAC_DINTSTSCLR	0x48
+#define SUDMAC_CH0SHCTRL	0x50
+
+/* Definitions for the sudmac_channel.config */
+#define SUDMAC_SENDBUFM	0x1000 /* b12: Transmit Buffer Mode */
+#define SUDMAC_RCVENDM	0x0100 /* b8: Receive Data Transfer End Mode */
+#define SUDMAC_LBA_WAIT	0x0030 /* b5-4: Local Bus Access Wait */
+
+/* Definitions for the sudmac_channel.dint_end_bit */
+#define SUDMAC_CH1ENDE	0x0002 /* b1: Ch1 DMA Transfer End Int Enable */
+#define SUDMAC_CH0ENDE	0x0001 /* b0: Ch0 DMA Transfer End Int Enable */
+
+#define SUDMAC_DRV_NAME "sudmac"
+
+static void sudmac_writel(struct sudmac_chan *sc, u32 data, u32 reg)
+{
+	iowrite32(data, sc->base + reg);
+}
+
+static u32 sudmac_readl(struct sudmac_chan *sc, u32 reg)
+{
+	return ioread32(sc->base + reg);
+}
+
+static bool sudmac_is_busy(struct sudmac_chan *sc)
+{
+	u32 den = sudmac_readl(sc, SUDMAC_CH0DEN + sc->offset);
+
+	if (den)
+		return true; /* working */
+
+	return false; /* waiting */
+}
+
+static void sudmac_set_reg(struct sudmac_chan *sc, struct sudmac_regs *hw,
+			   struct shdma_desc *sdesc)
+{
+	sudmac_writel(sc, sc->cfg, SUDMAC_CH0CFG + sc->offset);
+	sudmac_writel(sc, hw->base_addr, SUDMAC_CH0BA + sc->offset);
+	sudmac_writel(sc, hw->base_byte_count, SUDMAC_CH0BBC + sc->offset);
+}
+
+static void sudmac_start(struct sudmac_chan *sc)
+{
+	u32 dintctrl = sudmac_readl(sc, SUDMAC_DINTCTRL);
+
+	sudmac_writel(sc, dintctrl | sc->dint_end_bit, SUDMAC_DINTCTRL);
+	sudmac_writel(sc, 1, SUDMAC_CH0DEN + sc->offset);
+}
+
+static void sudmac_start_xfer(struct shdma_chan *schan,
+			      struct shdma_desc *sdesc)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	struct sudmac_desc *sd = to_desc(sdesc);
+
+	sudmac_set_reg(sc, &sd->hw, sdesc);
+	sudmac_start(sc);
+}
+
+static bool sudmac_channel_busy(struct shdma_chan *schan)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+
+	return sudmac_is_busy(sc);
+}
+
+static void sudmac_setup_xfer(struct shdma_chan *schan, int slave_id)
+{
+}
+
+static const struct sudmac_slave_config *sudmac_find_slave(
+	struct sudmac_chan *sc, int slave_id)
+{
+	struct sudmac_device *sdev = to_sdev(sc);
+	struct sudmac_pdata *pdata = sdev->pdata;
+	const struct sudmac_slave_config *cfg;
+	int i;
+
+	for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
+		if (cfg->slave_id == slave_id)
+			return cfg;
+
+	return NULL;
+}
+
+static int sudmac_set_slave(struct shdma_chan *schan, int slave_id, bool try)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	const struct sudmac_slave_config *cfg = sudmac_find_slave(sc, slave_id);
+
+	if (!cfg)
+		return -ENODEV;
+
+	return 0;
+}
+
+static inline void sudmac_dma_halt(struct sudmac_chan *sc)
+{
+	u32 dintctrl = sudmac_readl(sc, SUDMAC_DINTCTRL);
+
+	sudmac_writel(sc, 0, SUDMAC_CH0DEN + sc->offset);
+	sudmac_writel(sc, dintctrl & ~sc->dint_end_bit, SUDMAC_DINTCTRL);
+	sudmac_writel(sc, sc->dint_end_bit, SUDMAC_DINTSTSCLR);
+}
+
+static int sudmac_desc_setup(struct shdma_chan *schan,
+			     struct shdma_desc *sdesc,
+			     dma_addr_t src, dma_addr_t dst, size_t *len)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	struct sudmac_desc *sd = to_desc(sdesc);
+
+	dev_dbg(sc->shdma_chan.dev, "%s: src=%x, dst=%x, len=%d\n",
+		__func__, src, dst, *len);
+
+	if (*len > schan->max_xfer_len)
+		*len = schan->max_xfer_len;
+
+	if (dst)
+		sd->hw.base_addr = dst;
+	else if (src)
+		sd->hw.base_addr = src;
+	sd->hw.base_byte_count = *len;
+
+	return 0;
+}
+
+static void sudmac_halt(struct shdma_chan *schan)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+
+	sudmac_dma_halt(sc);
+}
+
+static bool sudmac_chan_irq(struct shdma_chan *schan, int irq)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	u32 dintsts = sudmac_readl(sc, SUDMAC_DINTSTS);
+
+	if (!(dintsts & sc->dint_end_bit))
+		return false;
+
+	/* DMA stop */
+	sudmac_dma_halt(sc);
+
+	return true;
+}
+
+static size_t sudmac_get_partial(struct shdma_chan *schan,
+				 struct shdma_desc *sdesc)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	struct sudmac_desc *sd = to_desc(sdesc);
+	u32 current_byte_count = sudmac_readl(sc, SUDMAC_CH0CBC + sc->offset);
+
+	return sd->hw.base_byte_count - current_byte_count;
+}
+
+static bool sudmac_desc_completed(struct shdma_chan *schan,
+				  struct shdma_desc *sdesc)
+{
+	struct sudmac_chan *sc = to_chan(schan);
+	struct sudmac_desc *sd = to_desc(sdesc);
+	u32 current_addr = sudmac_readl(sc, SUDMAC_CH0CA + sc->offset);
+
+	return sd->hw.base_addr + sd->hw.base_byte_count == current_addr;
+}
+
+static int sudmac_chan_probe(struct sudmac_device *su_dev, int id, int irq,
+			     unsigned long flags)
+{
+	struct shdma_dev *sdev = &su_dev->shdma_dev;
+	struct platform_device *pdev = to_platform_device(sdev->dma_dev.dev);
+	struct sudmac_chan *sc;
+	struct shdma_chan *schan;
+	int err;
+
+	sc = devm_kzalloc(&pdev->dev, sizeof(struct sudmac_chan), GFP_KERNEL);
+	if (!sc) {
+		dev_err(sdev->dma_dev.dev,
+			"No free memory for allocating dma channels!\n");
+		return -ENOMEM;
+	}
+
+	schan = &sc->shdma_chan;
+	schan->max_xfer_len = 64 * 1024 * 1024 - 1;
+
+	shdma_chan_probe(sdev, schan, id);
+
+	sc->base = su_dev->chan_reg;
+
+	/* get platform_data */
+	sc->offset = su_dev->pdata->channel->offset;
+	if (su_dev->pdata->channel->config & SUDMAC_TX_BUFFER_MODE)
+		sc->cfg |= SUDMAC_SENDBUFM;
+	if (su_dev->pdata->channel->config & SUDMAC_RX_END_MODE)
+		sc->cfg |= SUDMAC_RCVENDM;
+	sc->cfg |= (su_dev->pdata->channel->wait << 4) & SUDMAC_LBA_WAIT;
+
+	if (su_dev->pdata->channel->dint_end_bit & SUDMAC_DMA_BIT_CH0)
+		sc->dint_end_bit |= SUDMAC_CH0ENDE;
+	if (su_dev->pdata->channel->dint_end_bit & SUDMAC_DMA_BIT_CH1)
+		sc->dint_end_bit |= SUDMAC_CH1ENDE;
+
+	/* set up channel irq */
+	if (pdev->id >= 0)
+		snprintf(sc->dev_id, sizeof(sc->dev_id), "sudmac%d.%d",
+			 pdev->id, id);
+	else
+		snprintf(sc->dev_id, sizeof(sc->dev_id), "sudmac%d", id);
+
+	err = shdma_request_irq(schan, irq, flags, sc->dev_id);
+	if (err) {
+		dev_err(sdev->dma_dev.dev,
+			"DMA channel %d request_irq failed %d\n", id, err);
+		goto err_no_irq;
+	}
+
+	return 0;
+
+err_no_irq:
+	/* remove from dmaengine device node */
+	shdma_chan_remove(schan);
+	return err;
+}
+
+static void sudmac_chan_remove(struct sudmac_device *su_dev)
+{
+	struct dma_device *dma_dev = &su_dev->shdma_dev.dma_dev;
+	struct shdma_chan *schan;
+	int i;
+
+	shdma_for_each_chan(schan, &su_dev->shdma_dev, i) {
+		struct sudmac_chan *sc = to_chan(schan);
+
+		BUG_ON(!schan);
+
+		shdma_free_irq(&sc->shdma_chan);
+		shdma_chan_remove(schan);
+	}
+	dma_dev->chancnt = 0;
+}
+
+static dma_addr_t sudmac_slave_addr(struct shdma_chan *schan)
+{
+	/* SUDMAC doesn't need the address */
+	return 0;
+}
+
+static struct shdma_desc *sudmac_embedded_desc(void *buf, int i)
+{
+	return &((struct sudmac_desc *)buf)[i].shdma_desc;
+}
+
+static const struct shdma_ops sudmac_shdma_ops = {
+	.desc_completed = sudmac_desc_completed,
+	.halt_channel = sudmac_halt,
+	.channel_busy = sudmac_channel_busy,
+	.slave_addr = sudmac_slave_addr,
+	.desc_setup = sudmac_desc_setup,
+	.set_slave = sudmac_set_slave,
+	.setup_xfer = sudmac_setup_xfer,
+	.start_xfer = sudmac_start_xfer,
+	.embedded_desc = sudmac_embedded_desc,
+	.chan_irq = sudmac_chan_irq,
+	.get_partial = sudmac_get_partial,
+};
+
+static int sudmac_probe(struct platform_device *pdev)
+{
+	struct sudmac_pdata *pdata = pdev->dev.platform_data;
+	int err, i;
+	struct sudmac_device *su_dev;
+	struct dma_device *dma_dev;
+	struct resource *chan, *irq_res;
+
+	/* get platform data */
+	if (!pdata)
+		return -ENODEV;
+
+	chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!chan || !irq_res)
+		return -ENODEV;
+
+	err = -ENOMEM;
+	su_dev = devm_kzalloc(&pdev->dev, sizeof(struct sudmac_device),
+			      GFP_KERNEL);
+	if (!su_dev) {
+		dev_err(&pdev->dev, "Not enough memory\n");
+		return err;
+	}
+
+	dma_dev = &su_dev->shdma_dev.dma_dev;
+
+	su_dev->chan_reg = devm_request_and_ioremap(&pdev->dev, chan);
+	if (!su_dev->chan_reg)
+		return err;
+
+	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+
+	su_dev->shdma_dev.ops = &sudmac_shdma_ops;
+	su_dev->shdma_dev.desc_size = sizeof(struct sudmac_desc);
+	err = shdma_init(&pdev->dev, &su_dev->shdma_dev, pdata->channel_num);
+	if (err < 0)
+		return err;
+
+	/* platform data */
+	su_dev->pdata = pdev->dev.platform_data;
+
+	platform_set_drvdata(pdev, su_dev);
+
+	/* Create DMA Channel */
+	for (i = 0; i < pdata->channel_num; i++) {
+		err = sudmac_chan_probe(su_dev, i, irq_res->start, IRQF_SHARED);
+		if (err)
+			goto chan_probe_err;
+	}
+
+	err = dma_async_device_register(&su_dev->shdma_dev.dma_dev);
+	if (err < 0)
+		goto chan_probe_err;
+
+	return err;
+
+chan_probe_err:
+	sudmac_chan_remove(su_dev);
+
+	platform_set_drvdata(pdev, NULL);
+	shdma_cleanup(&su_dev->shdma_dev);
+
+	return err;
+}
+
+static int sudmac_remove(struct platform_device *pdev)
+{
+	struct sudmac_device *su_dev = platform_get_drvdata(pdev);
+	struct dma_device *dma_dev = &su_dev->shdma_dev.dma_dev;
+
+	dma_async_device_unregister(dma_dev);
+	sudmac_chan_remove(su_dev);
+	shdma_cleanup(&su_dev->shdma_dev);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver sudmac_driver = {
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= SUDMAC_DRV_NAME,
+	},
+	.probe		= sudmac_probe,
+	.remove		= sudmac_remove,
+};
+module_platform_driver(sudmac_driver);
+
+MODULE_AUTHOR("Yoshihiro Shimoda");
+MODULE_DESCRIPTION("Renesas SUDMAC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" SUDMAC_DRV_NAME);

include/linux/sudmac.h

@@ -0,0 +1,52 @@
+/*
+ * Header for the SUDMAC driver
+ *
+ * Copyright (C) 2013 Renesas Solutions Corp.
+ *
+ * This 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.
+ */
+#ifndef SUDMAC_H
+#define SUDMAC_H
+
+#include <linux/dmaengine.h>
+#include <linux/shdma-base.h>
+#include <linux/types.h>
+
+/* Used by slave DMA clients to request DMA to/from a specific peripheral */
+struct sudmac_slave {
+	struct shdma_slave	shdma_slave;	/* Set by the platform */
+};
+
+/*
+ * Supplied by platforms to specify, how a DMA channel has to be configured for
+ * a certain peripheral
+ */
+struct sudmac_slave_config {
+	int		slave_id;
+};
+
+struct sudmac_channel {
+	unsigned long	offset;
+	unsigned long	config;
+	unsigned long	wait;		/* The configuable range is 0 to 3 */
+	unsigned long	dint_end_bit;
+};
+
+struct sudmac_pdata {
+	const struct sudmac_slave_config *slave;
+	int slave_num;
+	const struct sudmac_channel *channel;
+	int channel_num;
+};
+
+/* Definitions for the sudmac_channel.config */
+#define SUDMAC_TX_BUFFER_MODE	BIT(0)
+#define SUDMAC_RX_END_MODE	BIT(1)
+
+/* Definitions for the sudmac_channel.dint_end_bit */
+#define SUDMAC_DMA_BIT_CH0	BIT(0)
+#define SUDMAC_DMA_BIT_CH1	BIT(1)
+
+#endif