dmaengine: Add Synopsys eDMA IP version 0 support

Add support for the eDMA IP version 0 driver for both register maps (legacy
and unroll).

The legacy register mapping was the initial implementation, which consisted
in having all registers belonging to channels multiplexed, which could be
change anytime (which could led a race-condition) by view port register
(access to only one channel available each time).

This register mapping is not very effective and efficient in a multithread
environment, which has led to the development of unroll registers mapping,
which consists of having all channels registers accessible any time by
spreading all channels registers by an offset between them.

This version supports a maximum of 16 independent channels (8 write +
8 read), which can run simultaneously.

Implements a scatter-gather transfer through a linked list, where the size
of linked list depends on the allocated memory divided equally among all
channels.

Each linked list descriptor can transfer from 1 byte to 4 Gbytes and is
alignmented to DWORD.

Both SAR (Source Address Register) and DAR (Destination Address Register)
are alignmented to byte.

Signed-off-by: Gustavo Pimentel <[email protected]>
Cc: Vinod Koul <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Russell King <[email protected]>
Cc: Joao Pinto <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>

Author: gustavoSNPS

drivers/dma/dw-edma/Makefile

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_DW_EDMA)		+= dw-edma.o
-dw-edma-objs			:= dw-edma-core.o
+dw-edma-objs			:= dw-edma-core.o \
+					dw-edma-v0-core.o

drivers/dma/dw-edma/dw-edma-core.c

@@ -17,6 +17,7 @@
 #include <linux/pci.h>
 
 #include "dw-edma-core.h"
+#include "dw-edma-v0-core.h"
 #include "../dmaengine.h"
 #include "../virt-dma.h"
 

drivers/dma/dw-edma/dw-edma-v0-core.c

@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare eDMA v0 core
+ *
+ * Author: Gustavo Pimentel <[email protected]>
+ */
+
+#include <linux/bitfield.h>
+
+#include "dw-edma-core.h"
+#include "dw-edma-v0-core.h"
+#include "dw-edma-v0-regs.h"
+#include "dw-edma-v0-debugfs.h"
+
+enum dw_edma_control {
+	DW_EDMA_V0_CB					= BIT(0),
+	DW_EDMA_V0_TCB					= BIT(1),
+	DW_EDMA_V0_LLP					= BIT(2),
+	DW_EDMA_V0_LIE					= BIT(3),
+	DW_EDMA_V0_RIE					= BIT(4),
+	DW_EDMA_V0_CCS					= BIT(8),
+	DW_EDMA_V0_LLE					= BIT(9),
+};
+
+static inline struct dw_edma_v0_regs __iomem *__dw_regs(struct dw_edma *dw)
+{
+	return (struct dw_edma_v0_regs __iomem *)dw->rg_region.vaddr;
+}
+
+#define SET(dw, name, value)				\
+	writel(value, &(__dw_regs(dw)->name))
+
+#define GET(dw, name)					\
+	readl(&(__dw_regs(dw)->name))
+
+#define SET_RW(dw, dir, name, value)			\
+	do {						\
+		if ((dir) == EDMA_DIR_WRITE)		\
+			SET(dw, wr_##name, value);	\
+		else					\
+			SET(dw, rd_##name, value);	\
+	} while (0)
+
+#define GET_RW(dw, dir, name)				\
+	((dir) == EDMA_DIR_WRITE			\
+	  ? GET(dw, wr_##name)				\
+	  : GET(dw, rd_##name))
+
+#define SET_BOTH(dw, name, value)			\
+	do {						\
+		SET(dw, wr_##name, value);		\
+		SET(dw, rd_##name, value);		\
+	} while (0)
+
+static inline struct dw_edma_v0_ch_regs __iomem *
+__dw_ch_regs(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch)
+{
+	if (dw->mode == EDMA_MODE_LEGACY)
+		return &(__dw_regs(dw)->type.legacy.ch);
+
+	if (dir == EDMA_DIR_WRITE)
+		return &__dw_regs(dw)->type.unroll.ch[ch].wr;
+
+	return &__dw_regs(dw)->type.unroll.ch[ch].rd;
+}
+
+static inline void writel_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
+			     u32 value, void __iomem *addr)
+{
+	if (dw->mode == EDMA_MODE_LEGACY) {
+		u32 viewport_sel;
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&dw->lock, flags);
+
+		viewport_sel = FIELD_PREP(EDMA_V0_VIEWPORT_MASK, ch);
+		if (dir == EDMA_DIR_READ)
+			viewport_sel |= BIT(31);
+
+		writel(viewport_sel,
+		       &(__dw_regs(dw)->type.legacy.viewport_sel));
+		writel(value, addr);
+
+		raw_spin_unlock_irqrestore(&dw->lock, flags);
+	} else {
+		writel(value, addr);
+	}
+}
+
+static inline u32 readl_ch(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch,
+			   const void __iomem *addr)
+{
+	u32 value;
+
+	if (dw->mode == EDMA_MODE_LEGACY) {
+		u32 viewport_sel;
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&dw->lock, flags);
+
+		viewport_sel = FIELD_PREP(EDMA_V0_VIEWPORT_MASK, ch);
+		if (dir == EDMA_DIR_READ)
+			viewport_sel |= BIT(31);
+
+		writel(viewport_sel,
+		       &(__dw_regs(dw)->type.legacy.viewport_sel));
+		value = readl(addr);
+
+		raw_spin_unlock_irqrestore(&dw->lock, flags);
+	} else {
+		value = readl(addr);
+	}
+
+	return value;
+}
+
+#define SET_CH(dw, dir, ch, name, value) \
+	writel_ch(dw, dir, ch, value, &(__dw_ch_regs(dw, dir, ch)->name))
+
+#define GET_CH(dw, dir, ch, name) \
+	readl_ch(dw, dir, ch, &(__dw_ch_regs(dw, dir, ch)->name))
+
+#define SET_LL(ll, value) \
+	writel(value, ll)
+
+/* eDMA management callbacks */
+void dw_edma_v0_core_off(struct dw_edma *dw)
+{
+	SET_BOTH(dw, int_mask, EDMA_V0_DONE_INT_MASK | EDMA_V0_ABORT_INT_MASK);
+	SET_BOTH(dw, int_clear, EDMA_V0_DONE_INT_MASK | EDMA_V0_ABORT_INT_MASK);
+	SET_BOTH(dw, engine_en, 0);
+}
+
+u16 dw_edma_v0_core_ch_count(struct dw_edma *dw, enum dw_edma_dir dir)
+{
+	u32 num_ch;
+
+	if (dir == EDMA_DIR_WRITE)
+		num_ch = FIELD_GET(EDMA_V0_WRITE_CH_COUNT_MASK, GET(dw, ctrl));
+	else
+		num_ch = FIELD_GET(EDMA_V0_READ_CH_COUNT_MASK, GET(dw, ctrl));
+
+	if (num_ch > EDMA_V0_MAX_NR_CH)
+		num_ch = EDMA_V0_MAX_NR_CH;
+
+	return (u16)num_ch;
+}
+
+enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan)
+{
+	struct dw_edma *dw = chan->chip->dw;
+	u32 tmp;
+
+	tmp = FIELD_GET(EDMA_V0_CH_STATUS_MASK,
+			GET_CH(dw, chan->dir, chan->id, ch_control1));
+
+	if (tmp == 1)
+		return DMA_IN_PROGRESS;
+	else if (tmp == 3)
+		return DMA_COMPLETE;
+	else
+		return DMA_ERROR;
+}
+
+void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan)
+{
+	struct dw_edma *dw = chan->chip->dw;
+
+	SET_RW(dw, chan->dir, int_clear,
+	       FIELD_PREP(EDMA_V0_DONE_INT_MASK, BIT(chan->id)));
+}
+
+void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan)
+{
+	struct dw_edma *dw = chan->chip->dw;
+
+	SET_RW(dw, chan->dir, int_clear,
+	       FIELD_PREP(EDMA_V0_ABORT_INT_MASK, BIT(chan->id)));
+}
+
+u32 dw_edma_v0_core_status_done_int(struct dw_edma *dw, enum dw_edma_dir dir)
+{
+	return FIELD_GET(EDMA_V0_DONE_INT_MASK, GET_RW(dw, dir, int_status));
+}
+
+u32 dw_edma_v0_core_status_abort_int(struct dw_edma *dw, enum dw_edma_dir dir)
+{
+	return FIELD_GET(EDMA_V0_ABORT_INT_MASK, GET_RW(dw, dir, int_status));
+}
+
+static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
+{
+	struct dw_edma_burst *child;
+	struct dw_edma_v0_lli *lli;
+	struct dw_edma_v0_llp *llp;
+	u32 control = 0, i = 0;
+	u64 sar, dar, addr;
+	int j;
+
+	lli = (struct dw_edma_v0_lli *)chunk->ll_region.vaddr;
+
+	if (chunk->cb)
+		control = DW_EDMA_V0_CB;
+
+	j = chunk->bursts_alloc;
+	list_for_each_entry(child, &chunk->burst->list, list) {
+		j--;
+		if (!j)
+			control |= (DW_EDMA_V0_LIE | DW_EDMA_V0_RIE);
+
+		/* Channel control */
+		SET_LL(&lli[i].control, control);
+		/* Transfer size */
+		SET_LL(&lli[i].transfer_size, child->sz);
+		/* SAR - low, high */
+		sar = cpu_to_le64(child->sar);
+		SET_LL(&lli[i].sar_low, lower_32_bits(sar));
+		SET_LL(&lli[i].sar_high, upper_32_bits(sar));
+		/* DAR - low, high */
+		dar = cpu_to_le64(child->dar);
+		SET_LL(&lli[i].dar_low, lower_32_bits(dar));
+		SET_LL(&lli[i].dar_high, upper_32_bits(dar));
+		i++;
+	}
+
+	llp = (struct dw_edma_v0_llp *)&lli[i];
+	control = DW_EDMA_V0_LLP | DW_EDMA_V0_TCB;
+	if (!chunk->cb)
+		control |= DW_EDMA_V0_CB;
+
+	/* Channel control */
+	SET_LL(&llp->control, control);
+	/* Linked list  - low, high */
+	addr = cpu_to_le64(chunk->ll_region.paddr);
+	SET_LL(&llp->llp_low, lower_32_bits(addr));
+	SET_LL(&llp->llp_high, upper_32_bits(addr));
+}
+
+void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
+{
+	struct dw_edma_chan *chan = chunk->chan;
+	struct dw_edma *dw = chan->chip->dw;
+	u32 tmp;
+	u64 llp;
+
+	dw_edma_v0_core_write_chunk(chunk);
+
+	if (first) {
+		/* Enable engine */
+		SET_RW(dw, chan->dir, engine_en, BIT(0));
+		/* Interrupt unmask - done, abort */
+		tmp = GET_RW(dw, chan->dir, int_mask);
+		tmp &= ~FIELD_PREP(EDMA_V0_DONE_INT_MASK, BIT(chan->id));
+		tmp &= ~FIELD_PREP(EDMA_V0_ABORT_INT_MASK, BIT(chan->id));
+		SET_RW(dw, chan->dir, int_mask, tmp);
+		/* Linked list error */
+		tmp = GET_RW(dw, chan->dir, linked_list_err_en);
+		tmp |= FIELD_PREP(EDMA_V0_LINKED_LIST_ERR_MASK, BIT(chan->id));
+		SET_RW(dw, chan->dir, linked_list_err_en, tmp);
+		/* Channel control */
+		SET_CH(dw, chan->dir, chan->id, ch_control1,
+		       (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));
+		/* Linked list - low, high */
+		llp = cpu_to_le64(chunk->ll_region.paddr);
+		SET_CH(dw, chan->dir, chan->id, llp_low, lower_32_bits(llp));
+		SET_CH(dw, chan->dir, chan->id, llp_high, upper_32_bits(llp));
+	}
+	/* Doorbell */
+	SET_RW(dw, chan->dir, doorbell,
+	       FIELD_PREP(EDMA_V0_DOORBELL_CH_MASK, chan->id));
+}
+
+int dw_edma_v0_core_device_config(struct dw_edma_chan *chan)
+{
+	struct dw_edma *dw = chan->chip->dw;
+	u32 tmp = 0;
+
+	/* MSI done addr - low, high */
+	SET_RW(dw, chan->dir, done_imwr_low, chan->msi.address_lo);
+	SET_RW(dw, chan->dir, done_imwr_high, chan->msi.address_hi);
+	/* MSI abort addr - low, high */
+	SET_RW(dw, chan->dir, abort_imwr_low, chan->msi.address_lo);
+	SET_RW(dw, chan->dir, abort_imwr_high, chan->msi.address_hi);
+	/* MSI data - low, high */
+	switch (chan->id) {
+	case 0:
+	case 1:
+		tmp = GET_RW(dw, chan->dir, ch01_imwr_data);
+		break;
+
+	case 2:
+	case 3:
+		tmp = GET_RW(dw, chan->dir, ch23_imwr_data);
+		break;
+
+	case 4:
+	case 5:
+		tmp = GET_RW(dw, chan->dir, ch45_imwr_data);
+		break;
+
+	case 6:
+	case 7:
+		tmp = GET_RW(dw, chan->dir, ch67_imwr_data);
+		break;
+	}
+
+	if (chan->id & BIT(0)) {
+		/* Channel odd {1, 3, 5, 7} */
+		tmp &= EDMA_V0_CH_EVEN_MSI_DATA_MASK;
+		tmp |= FIELD_PREP(EDMA_V0_CH_ODD_MSI_DATA_MASK,
+				  chan->msi.data);
+	} else {
+		/* Channel even {0, 2, 4, 6} */
+		tmp &= EDMA_V0_CH_ODD_MSI_DATA_MASK;
+		tmp |= FIELD_PREP(EDMA_V0_CH_EVEN_MSI_DATA_MASK,
+				  chan->msi.data);
+	}
+
+	switch (chan->id) {
+	case 0:
+	case 1:
+		SET_RW(dw, chan->dir, ch01_imwr_data, tmp);
+		break;
+
+	case 2:
+	case 3:
+		SET_RW(dw, chan->dir, ch23_imwr_data, tmp);
+		break;
+
+	case 4:
+	case 5:
+		SET_RW(dw, chan->dir, ch45_imwr_data, tmp);
+		break;
+
+	case 6:
+	case 7:
+		SET_RW(dw, chan->dir, ch67_imwr_data, tmp);
+		break;
+	}
+
+	return 0;
+}
+
+/* eDMA debugfs callbacks */
+void dw_edma_v0_core_debugfs_on(struct dw_edma_chip *chip)
+{
+}
+
+void dw_edma_v0_core_debugfs_off(void)
+{
+}

drivers/dma/dw-edma/dw-edma-v0-core.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
+ * Synopsys DesignWare eDMA v0 core
+ *
+ * Author: Gustavo Pimentel <[email protected]>
+ */
+
+#ifndef _DW_EDMA_V0_CORE_H
+#define _DW_EDMA_V0_CORE_H
+
+#include <linux/dma/edma.h>
+
+/* eDMA management callbacks */
+void dw_edma_v0_core_off(struct dw_edma *chan);
+u16 dw_edma_v0_core_ch_count(struct dw_edma *chan, enum dw_edma_dir dir);
+enum dma_status dw_edma_v0_core_ch_status(struct dw_edma_chan *chan);
+void dw_edma_v0_core_clear_done_int(struct dw_edma_chan *chan);
+void dw_edma_v0_core_clear_abort_int(struct dw_edma_chan *chan);
+u32 dw_edma_v0_core_status_done_int(struct dw_edma *chan, enum dw_edma_dir dir);
+u32 dw_edma_v0_core_status_abort_int(struct dw_edma *chan, enum dw_edma_dir dir);
+void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first);
+int dw_edma_v0_core_device_config(struct dw_edma_chan *chan);
+/* eDMA debug fs callbacks */
+void dw_edma_v0_core_debugfs_on(struct dw_edma_chip *chip);
+void dw_edma_v0_core_debugfs_off(void);
+
+#endif /* _DW_EDMA_V0_CORE_H */