1 files changed, 425 insertions, 0 deletions
diff --git a/arch/sh/drivers/dma/dma-sh.c b/arch/sh/drivers/dma/dma-sh.c
new file mode 100644
index 0000000000..306fba1564
--- /dev/null
+++ b/arch/sh/drivers/dma/dma-sh.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/sh/drivers/dma/dma-sh.c
+ *
+ * SuperH On-chip DMAC Support
+ *
+ * Copyright (C) 2000 Takashi YOSHII
+ * Copyright (C) 2003, 2004 Paul Mundt
+ * Copyright (C) 2005 Andriy Skulysh
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <mach-dreamcast/mach/dma.h>
+#include <asm/dma.h>
+#include <asm/dma-register.h>
+#include <cpu/dma-register.h>
+#include <cpu/dma.h>
+
+/*
+ * Some of the SoCs feature two DMAC modules. In such a case, the channels are
+ * distributed equally among them.
+ */
+#ifdef	SH_DMAC_BASE1
+#define	SH_DMAC_NR_MD_CH	(CONFIG_NR_ONCHIP_DMA_CHANNELS / 2)
+#else
+#define	SH_DMAC_NR_MD_CH	CONFIG_NR_ONCHIP_DMA_CHANNELS
+#endif
+
+#define	SH_DMAC_CH_SZ		0x10
+
+/*
+ * Define the default configuration for dual address memory-memory transfer.
+ * The 0x400 value represents auto-request, external->external.
+ */
+#define RS_DUAL	(DM_INC | SM_INC | RS_AUTO | TS_INDEX2VAL(XMIT_SZ_32BIT))
+
+static unsigned long dma_find_base(unsigned int chan)
+{
+	unsigned long base = SH_DMAC_BASE0;
+
+#ifdef SH_DMAC_BASE1
+	if (chan >= SH_DMAC_NR_MD_CH)
+		base = SH_DMAC_BASE1;
+#endif
+
+	return base;
+}
+
+static unsigned long dma_base_addr(unsigned int chan)
+{
+	unsigned long base = dma_find_base(chan);
+
+	chan = (chan % SH_DMAC_NR_MD_CH) * SH_DMAC_CH_SZ;
+
+	/* DMAOR is placed inside the channel register space. Step over it. */
+	if (chan >= DMAOR)
+		base += SH_DMAC_CH_SZ;
+
+	return base + chan;
+}
+
+#ifdef CONFIG_SH_DMA_IRQ_MULTI
+static inline unsigned int get_dmte_irq(unsigned int chan)
+{
+	return chan >= 6 ? DMTE6_IRQ : DMTE0_IRQ;
+}
+#else
+
+static unsigned int dmte_irq_map[] = {
+	DMTE0_IRQ, DMTE0_IRQ + 1, DMTE0_IRQ + 2, DMTE0_IRQ + 3,
+
+#ifdef DMTE4_IRQ
+	DMTE4_IRQ, DMTE4_IRQ + 1,
+#endif
+
+#ifdef DMTE6_IRQ
+	DMTE6_IRQ, DMTE6_IRQ + 1,
+#endif
+
+#ifdef DMTE8_IRQ
+	DMTE8_IRQ, DMTE9_IRQ, DMTE10_IRQ, DMTE11_IRQ,
+#endif
+};
+
+static inline unsigned int get_dmte_irq(unsigned int chan)
+{
+	return dmte_irq_map[chan];
+}
+#endif
+
+/*
+ * We determine the correct shift size based off of the CHCR transmit size
+ * for the given channel. Since we know that it will take:
+ *
+ *	info->count >> ts_shift[transmit_size]
+ *
+ * iterations to complete the transfer.
+ */
+static unsigned int ts_shift[] = TS_SHIFT;
+
+static inline unsigned int calc_xmit_shift(struct dma_channel *chan)
+{
+	u32 chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
+	int cnt = ((chcr & CHCR_TS_LOW_MASK) >> CHCR_TS_LOW_SHIFT) |
+		((chcr & CHCR_TS_HIGH_MASK) >> CHCR_TS_HIGH_SHIFT);
+
+	return ts_shift[cnt];
+}
+
+/*
+ * The transfer end interrupt must read the chcr register to end the
+ * hardware interrupt active condition.
+ * Besides that it needs to waken any waiting process, which should handle
+ * setting up the next transfer.
+ */
+static irqreturn_t dma_tei(int irq, void *dev_id)
+{
+	struct dma_channel *chan = dev_id;
+	u32 chcr;
+
+	chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
+
+	if (!(chcr & CHCR_TE))
+		return IRQ_NONE;
+
+	chcr &= ~(CHCR_IE | CHCR_DE);
+	__raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
+
+	wake_up(&chan->wait_queue);
+
+	return IRQ_HANDLED;
+}
+
+static int sh_dmac_request_dma(struct dma_channel *chan)
+{
+	if (unlikely(!(chan->flags & DMA_TEI_CAPABLE)))
+		return 0;
+
+	return request_irq(get_dmte_irq(chan->chan), dma_tei, IRQF_SHARED,
+			   chan->dev_id, chan);
+}
+
+static void sh_dmac_free_dma(struct dma_channel *chan)
+{
+	free_irq(get_dmte_irq(chan->chan), chan);
+}
+
+static int
+sh_dmac_configure_channel(struct dma_channel *chan, unsigned long chcr)
+{
+	if (!chcr)
+		chcr = RS_DUAL | CHCR_IE;
+
+	if (chcr & CHCR_IE) {
+		chcr &= ~CHCR_IE;
+		chan->flags |= DMA_TEI_CAPABLE;
+	} else {
+		chan->flags &= ~DMA_TEI_CAPABLE;
+	}
+
+	__raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
+
+	chan->flags |= DMA_CONFIGURED;
+	return 0;
+}
+
+static void sh_dmac_enable_dma(struct dma_channel *chan)
+{
+	int irq;
+	u32 chcr;
+
+	chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
+	chcr |= CHCR_DE;
+
+	if (chan->flags & DMA_TEI_CAPABLE)
+		chcr |= CHCR_IE;
+
+	__raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
+
+	if (chan->flags & DMA_TEI_CAPABLE) {
+		irq = get_dmte_irq(chan->chan);
+		enable_irq(irq);
+	}
+}
+
+static void sh_dmac_disable_dma(struct dma_channel *chan)
+{
+	int irq;
+	u32 chcr;
+
+	if (chan->flags & DMA_TEI_CAPABLE) {
+		irq = get_dmte_irq(chan->chan);
+		disable_irq(irq);
+	}
+
+	chcr = __raw_readl(dma_base_addr(chan->chan) + CHCR);
+	chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
+	__raw_writel(chcr, (dma_base_addr(chan->chan) + CHCR));
+}
+
+static int sh_dmac_xfer_dma(struct dma_channel *chan)
+{
+	/*
+	 * If we haven't pre-configured the channel with special flags, use
+	 * the defaults.
+	 */
+	if (unlikely(!(chan->flags & DMA_CONFIGURED)))
+		sh_dmac_configure_channel(chan, 0);
+
+	sh_dmac_disable_dma(chan);
+
+	/*
+	 * Single-address mode usage note!
+	 *
+	 * It's important that we don't accidentally write any value to SAR/DAR
+	 * (this includes 0) that hasn't been directly specified by the user if
+	 * we're in single-address mode.
+	 *
+	 * In this case, only one address can be defined, anything else will
+	 * result in a DMA address error interrupt (at least on the SH-4),
+	 * which will subsequently halt the transfer.
+	 *
+	 * Channel 2 on the Dreamcast is a special case, as this is used for
+	 * cascading to the PVR2 DMAC. In this case, we still need to write
+	 * SAR and DAR, regardless of value, in order for cascading to work.
+	 */
+	if (chan->sar || (mach_is_dreamcast() &&
+			  chan->chan == PVR2_CASCADE_CHAN))
+		__raw_writel(chan->sar, (dma_base_addr(chan->chan) + SAR));
+	if (chan->dar || (mach_is_dreamcast() &&
+			  chan->chan == PVR2_CASCADE_CHAN))
+		__raw_writel(chan->dar, (dma_base_addr(chan->chan) + DAR));
+
+	__raw_writel(chan->count >> calc_xmit_shift(chan),
+		(dma_base_addr(chan->chan) + TCR));
+
+	sh_dmac_enable_dma(chan);
+
+	return 0;
+}
+
+static int sh_dmac_get_dma_residue(struct dma_channel *chan)
+{
+	if (!(__raw_readl(dma_base_addr(chan->chan) + CHCR) & CHCR_DE))
+		return 0;
+
+	return __raw_readl(dma_base_addr(chan->chan) + TCR)
+		 << calc_xmit_shift(chan);
+}
+
+/*
+ * DMAOR handling
+ */
+#if defined(CONFIG_CPU_SUBTYPE_SH7723)	|| \
+    defined(CONFIG_CPU_SUBTYPE_SH7724)	|| \
+    defined(CONFIG_CPU_SUBTYPE_SH7780)	|| \
+    defined(CONFIG_CPU_SUBTYPE_SH7785)
+#define NR_DMAOR	2
+#else
+#define NR_DMAOR	1
+#endif
+
+#define dmaor_read_reg(n)		__raw_readw(dma_find_base((n) * \
+						    SH_DMAC_NR_MD_CH) + DMAOR)
+#define dmaor_write_reg(n, data)	__raw_writew(data, \
+						     dma_find_base((n) * \
+						     SH_DMAC_NR_MD_CH) + DMAOR)
+
+static inline int dmaor_reset(int no)
+{
+	unsigned long dmaor = dmaor_read_reg(no);
+
+	/* Try to clear the error flags first, incase they are set */
+	dmaor &= ~(DMAOR_NMIF | DMAOR_AE);
+	dmaor_write_reg(no, dmaor);
+
+	dmaor |= DMAOR_INIT;
+	dmaor_write_reg(no, dmaor);
+
+	/* See if we got an error again */
+	if ((dmaor_read_reg(no) & (DMAOR_AE | DMAOR_NMIF))) {
+		printk(KERN_ERR "dma-sh: Can't initialize DMAOR.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * DMAE handling
+ */
+#ifdef CONFIG_CPU_SH4
+
+#if defined(DMAE1_IRQ)
+#define NR_DMAE		2
+#else
+#define NR_DMAE		1
+#endif
+
+static const char *dmae_name[] = {
+	"DMAC Address Error0",
+	"DMAC Address Error1"
+};
+
+#ifdef CONFIG_SH_DMA_IRQ_MULTI
+static inline unsigned int get_dma_error_irq(int n)
+{
+	return get_dmte_irq(n * 6);
+}
+#else
+
+static unsigned int dmae_irq_map[] = {
+	DMAE0_IRQ,
+
+#ifdef DMAE1_IRQ
+	DMAE1_IRQ,
+#endif
+};
+
+static inline unsigned int get_dma_error_irq(int n)
+{
+	return dmae_irq_map[n];
+}
+#endif
+
+static irqreturn_t dma_err(int irq, void *dummy)
+{
+	int i;
+
+	for (i = 0; i < NR_DMAOR; i++)
+		dmaor_reset(i);
+
+	disable_irq(irq);
+
+	return IRQ_HANDLED;
+}
+
+static int dmae_irq_init(void)
+{
+	int n;
+
+	for (n = 0; n < NR_DMAE; n++) {
+		int i = request_irq(get_dma_error_irq(n), dma_err,
+				    IRQF_SHARED, dmae_name[n], (void *)dmae_name[n]);
+		if (unlikely(i < 0)) {
+			printk(KERN_ERR "%s request_irq fail\n", dmae_name[n]);
+			return i;
+		}
+	}
+
+	return 0;
+}
+
+static void dmae_irq_free(void)
+{
+	int n;
+
+	for (n = 0; n < NR_DMAE; n++)
+		free_irq(get_dma_error_irq(n), NULL);
+}
+#else
+static inline int dmae_irq_init(void)
+{
+	return 0;
+}
+
+static void dmae_irq_free(void)
+{
+}
+#endif
+
+static struct dma_ops sh_dmac_ops = {
+	.request	= sh_dmac_request_dma,
+	.free		= sh_dmac_free_dma,
+	.get_residue	= sh_dmac_get_dma_residue,
+	.xfer		= sh_dmac_xfer_dma,
+	.configure	= sh_dmac_configure_channel,
+};
+
+static struct dma_info sh_dmac_info = {
+	.name		= "sh_dmac",
+	.nr_channels	= CONFIG_NR_ONCHIP_DMA_CHANNELS,
+	.ops		= &sh_dmac_ops,
+	.flags		= DMAC_CHANNELS_TEI_CAPABLE,
+};
+
+static int __init sh_dmac_init(void)
+{
+	struct dma_info *info = &sh_dmac_info;
+	int i, rc;
+
+	/*
+	 * Initialize DMAE, for parts that support it.
+	 */
+	rc = dmae_irq_init();
+	if (unlikely(rc != 0))
+		return rc;
+
+	/*
+	 * Initialize DMAOR, and clean up any error flags that may have
+	 * been set.
+	 */
+	for (i = 0; i < NR_DMAOR; i++) {
+		rc = dmaor_reset(i);
+		if (unlikely(rc != 0))
+			return rc;
+	}
+
+	return register_dmac(info);
+}
+
+static void __exit sh_dmac_exit(void)
+{
+	dmae_irq_free();
+	unregister_dmac(&sh_dmac_info);
+}
+
+subsys_initcall(sh_dmac_init);
+module_exit(sh_dmac_exit);
+
+MODULE_AUTHOR("Takashi YOSHII, Paul Mundt, Andriy Skulysh");
+MODULE_DESCRIPTION("SuperH On-Chip DMAC Support");
+MODULE_LICENSE("GPL v2");