DMA: TXx9 Soc DMA Controller driver

This patch adds support for the integrated DMAC of the TXx9 family.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 307 insertions, 0 deletions

diff --git a/drivers/dma/txx9dmac.h b/drivers/dma/txx9dmac.h
new file mode 100644
index 000000000000..c907ff01d276
--- /dev/null
+++ b/drivers/dma/txx9dmac.h
@@ -0,0 +1,307 @@
+/*
+ * Driver for the TXx9 SoC DMA Controller
+ *
+ * Copyright (C) 2009 Atsushi Nemoto
+ *
+ * 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.
+ */
+#ifndef TXX9DMAC_H
+#define TXX9DMAC_H
+
+#include <linux/dmaengine.h>
+#include <asm/txx9/dmac.h>
+
+/*
+ * Design Notes:
+ *
+ * This DMAC have four channels and one FIFO buffer.  Each channel can
+ * be configured for memory-memory or device-memory transfer, but only
+ * one channel can do alignment-free memory-memory transfer at a time
+ * while the channel should occupy the FIFO buffer for effective
+ * transfers.
+ *
+ * Instead of dynamically assign the FIFO buffer to channels, I chose
+ * make one dedicated channel for memory-memory transfer.  The
+ * dedicated channel is public.  Other channels are private and used
+ * for slave transfer.  Some devices in the SoC are wired to certain
+ * DMA channel.
+ */
+
+#ifdef CONFIG_MACH_TX49XX
+static inline bool txx9_dma_have_SMPCHN(void)
+{
+        return true;
+}
+#define TXX9_DMA_USE_SIMPLE_CHAIN
+#else
+static inline bool txx9_dma_have_SMPCHN(void)
+{
+        return false;
+}
+#endif
+
+#ifdef __LITTLE_ENDIAN
+#ifdef CONFIG_MACH_TX49XX
+#define CCR_LE  TXX9_DMA_CCR_LE
+#define MCR_LE  0
+#else
+#define CCR_LE  0
+#define MCR_LE  TXX9_DMA_MCR_LE
+#endif
+#else
+#define CCR_LE  0
+#define MCR_LE  0
+#endif
+
+/*
+ * Redefine this macro to handle differences between 32- and 64-bit
+ * addressing, big vs. little endian, etc.
+ */
+#ifdef __BIG_ENDIAN
+#define TXX9_DMA_REG32(name)            u32 __pad_##name; u32 name
+#else
+#define TXX9_DMA_REG32(name)            u32 name; u32 __pad_##name
+#endif
+
+/* Hardware register definitions. */
+struct txx9dmac_cregs {
+#if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
+        TXX9_DMA_REG32(CHAR);   /* Chain Address Register */
+#else
+        u64 CHAR;               /* Chain Address Register */
+#endif
+        u64 SAR;                /* Source Address Register */
+        u64 DAR;                /* Destination Address Register */
+        TXX9_DMA_REG32(CNTR);   /* Count Register */
+        TXX9_DMA_REG32(SAIR);   /* Source Address Increment Register */
+        TXX9_DMA_REG32(DAIR);   /* Destination Address Increment Register */
+        TXX9_DMA_REG32(CCR);    /* Channel Control Register */
+        TXX9_DMA_REG32(CSR);    /* Channel Status Register */
+};
+struct txx9dmac_cregs32 {
+        u32 CHAR;
+        u32 SAR;
+        u32 DAR;
+        u32 CNTR;
+        u32 SAIR;
+        u32 DAIR;
+        u32 CCR;
+        u32 CSR;
+};
+
+struct txx9dmac_regs {
+        /* per-channel registers */
+        struct txx9dmac_cregs   CHAN[TXX9_DMA_MAX_NR_CHANNELS];
+        u64     __pad[9];
+        u64     MFDR;           /* Memory Fill Data Register */
+        TXX9_DMA_REG32(MCR);    /* Master Control Register */
+};
+struct txx9dmac_regs32 {
+        struct txx9dmac_cregs32 CHAN[TXX9_DMA_MAX_NR_CHANNELS];
+        u32     __pad[9];
+        u32     MFDR;
+        u32     MCR;
+};
+
+/* bits for MCR */
+#define TXX9_DMA_MCR_EIS(ch)    (0x10000000<<(ch))
+#define TXX9_DMA_MCR_DIS(ch)    (0x01000000<<(ch))
+#define TXX9_DMA_MCR_RSFIF      0x00000080
+#define TXX9_DMA_MCR_FIFUM(ch)  (0x00000008<<(ch))
+#define TXX9_DMA_MCR_LE         0x00000004
+#define TXX9_DMA_MCR_RPRT       0x00000002
+#define TXX9_DMA_MCR_MSTEN      0x00000001
+
+/* bits for CCRn */
+#define TXX9_DMA_CCR_IMMCHN     0x20000000
+#define TXX9_DMA_CCR_USEXFSZ    0x10000000
+#define TXX9_DMA_CCR_LE         0x08000000
+#define TXX9_DMA_CCR_DBINH      0x04000000
+#define TXX9_DMA_CCR_SBINH      0x02000000
+#define TXX9_DMA_CCR_CHRST      0x01000000
+#define TXX9_DMA_CCR_RVBYTE     0x00800000
+#define TXX9_DMA_CCR_ACKPOL     0x00400000
+#define TXX9_DMA_CCR_REQPL      0x00200000
+#define TXX9_DMA_CCR_EGREQ      0x00100000
+#define TXX9_DMA_CCR_CHDN       0x00080000
+#define TXX9_DMA_CCR_DNCTL      0x00060000
+#define TXX9_DMA_CCR_EXTRQ      0x00010000
+#define TXX9_DMA_CCR_INTRQD     0x0000e000
+#define TXX9_DMA_CCR_INTENE     0x00001000
+#define TXX9_DMA_CCR_INTENC     0x00000800
+#define TXX9_DMA_CCR_INTENT     0x00000400
+#define TXX9_DMA_CCR_CHNEN      0x00000200
+#define TXX9_DMA_CCR_XFACT      0x00000100
+#define TXX9_DMA_CCR_SMPCHN     0x00000020
+#define TXX9_DMA_CCR_XFSZ(order)        (((order) << 2) & 0x0000001c)
+#define TXX9_DMA_CCR_XFSZ_1     TXX9_DMA_CCR_XFSZ(0)
+#define TXX9_DMA_CCR_XFSZ_2     TXX9_DMA_CCR_XFSZ(1)
+#define TXX9_DMA_CCR_XFSZ_4     TXX9_DMA_CCR_XFSZ(2)
+#define TXX9_DMA_CCR_XFSZ_8     TXX9_DMA_CCR_XFSZ(3)
+#define TXX9_DMA_CCR_XFSZ_X4    TXX9_DMA_CCR_XFSZ(4)
+#define TXX9_DMA_CCR_XFSZ_X8    TXX9_DMA_CCR_XFSZ(5)
+#define TXX9_DMA_CCR_XFSZ_X16   TXX9_DMA_CCR_XFSZ(6)
+#define TXX9_DMA_CCR_XFSZ_X32   TXX9_DMA_CCR_XFSZ(7)
+#define TXX9_DMA_CCR_MEMIO      0x00000002
+#define TXX9_DMA_CCR_SNGAD      0x00000001
+
+/* bits for CSRn */
+#define TXX9_DMA_CSR_CHNEN      0x00000400
+#define TXX9_DMA_CSR_STLXFER    0x00000200
+#define TXX9_DMA_CSR_XFACT      0x00000100
+#define TXX9_DMA_CSR_ABCHC      0x00000080
+#define TXX9_DMA_CSR_NCHNC      0x00000040
+#define TXX9_DMA_CSR_NTRNFC     0x00000020
+#define TXX9_DMA_CSR_EXTDN      0x00000010
+#define TXX9_DMA_CSR_CFERR      0x00000008
+#define TXX9_DMA_CSR_CHERR      0x00000004
+#define TXX9_DMA_CSR_DESERR     0x00000002
+#define TXX9_DMA_CSR_SORERR     0x00000001
+
+struct txx9dmac_chan {
+        struct dma_chan         chan;
+        struct dma_device       dma;
+        struct txx9dmac_dev     *ddev;
+        void __iomem            *ch_regs;
+        struct tasklet_struct   tasklet;
+        int                     irq;
+        u32                     ccr;
+
+        spinlock_t              lock;
+
+        /* these other elements are all protected by lock */
+        dma_cookie_t            completed;
+        struct list_head        active_list;
+        struct list_head        queue;
+        struct list_head        free_list;
+
+        unsigned int            descs_allocated;
+};
+
+struct txx9dmac_dev {
+        void __iomem            *regs;
+        struct tasklet_struct   tasklet;
+        int                     irq;
+        struct txx9dmac_chan    *chan[TXX9_DMA_MAX_NR_CHANNELS];
+        bool                    have_64bit_regs;
+        unsigned int            descsize;
+};
+
+static inline bool __is_dmac64(const struct txx9dmac_dev *ddev)
+{
+        return ddev->have_64bit_regs;
+}
+
+static inline bool is_dmac64(const struct txx9dmac_chan *dc)
+{
+        return __is_dmac64(dc->ddev);
+}
+
+#ifdef TXX9_DMA_USE_SIMPLE_CHAIN
+/* Hardware descriptor definition. (for simple-chain) */
+struct txx9dmac_hwdesc {
+#if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
+        TXX9_DMA_REG32(CHAR);
+#else
+        u64 CHAR;
+#endif
+        u64 SAR;
+        u64 DAR;
+        TXX9_DMA_REG32(CNTR);
+};
+struct txx9dmac_hwdesc32 {
+        u32 CHAR;
+        u32 SAR;
+        u32 DAR;
+        u32 CNTR;
+};
+#else
+#define txx9dmac_hwdesc txx9dmac_cregs
+#define txx9dmac_hwdesc32 txx9dmac_cregs32
+#endif
+
+struct txx9dmac_desc {
+        /* FIRST values the hardware uses */
+        union {
+                struct txx9dmac_hwdesc hwdesc;
+                struct txx9dmac_hwdesc32 hwdesc32;
+        };
+
+        /* THEN values for driver housekeeping */
+        struct list_head                desc_node ____cacheline_aligned;
+        struct dma_async_tx_descriptor  txd;
+        size_t                          len;
+};
+
+#ifdef TXX9_DMA_USE_SIMPLE_CHAIN
+
+static inline bool txx9dmac_chan_INTENT(struct txx9dmac_chan *dc)
+{
+        return (dc->ccr & TXX9_DMA_CCR_INTENT) != 0;
+}
+
+static inline void txx9dmac_chan_set_INTENT(struct txx9dmac_chan *dc)
+{
+        dc->ccr |= TXX9_DMA_CCR_INTENT;
+}
+
+static inline void txx9dmac_desc_set_INTENT(struct txx9dmac_dev *ddev,
+                                            struct txx9dmac_desc *desc)
+{
+}
+
+static inline void txx9dmac_chan_set_SMPCHN(struct txx9dmac_chan *dc)
+{
+        dc->ccr |= TXX9_DMA_CCR_SMPCHN;
+}
+
+static inline void txx9dmac_desc_set_nosimple(struct txx9dmac_dev *ddev,
+                                              struct txx9dmac_desc *desc,
+                                              u32 sair, u32 dair, u32 ccr)
+{
+}
+
+#else /* TXX9_DMA_USE_SIMPLE_CHAIN */
+
+static inline bool txx9dmac_chan_INTENT(struct txx9dmac_chan *dc)
+{
+        return true;
+}
+
+static void txx9dmac_chan_set_INTENT(struct txx9dmac_chan *dc)
+{
+}
+
+static inline void txx9dmac_desc_set_INTENT(struct txx9dmac_dev *ddev,
+                                            struct txx9dmac_desc *desc)
+{
+        if (__is_dmac64(ddev))
+                desc->hwdesc.CCR |= TXX9_DMA_CCR_INTENT;
+        else
+                desc->hwdesc32.CCR |= TXX9_DMA_CCR_INTENT;
+}
+
+static inline void txx9dmac_chan_set_SMPCHN(struct txx9dmac_chan *dc)
+{
+}
+
+static inline void txx9dmac_desc_set_nosimple(struct txx9dmac_dev *ddev,
+                                              struct txx9dmac_desc *desc,
+                                              u32 sai, u32 dai, u32 ccr)
+{
+        if (__is_dmac64(ddev)) {
+                desc->hwdesc.SAIR = sai;
+                desc->hwdesc.DAIR = dai;
+                desc->hwdesc.CCR = ccr;
+        } else {
+                desc->hwdesc32.SAIR = sai;
+                desc->hwdesc32.DAIR = dai;
+                desc->hwdesc32.CCR = ccr;
+        }
+}
+
+#endif /* TXX9_DMA_USE_SIMPLE_CHAIN */
+
+#endif /* TXX9DMAC_H */