[Qemu-devel] [PATCH v2 3/4] xilinx_spi: initial version

[Peter A. G. Crosthwaite]

device model for xilinx XPS SPI controller (v2.0)

Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
---
changed from v1:
converted spi api to modified txrx style

 Makefile.target |    1 +
 hw/xilinx_spi.c |  482 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 483 insertions(+), 0 deletions(-)
 create mode 100644 hw/xilinx_spi.c

diff --git a/Makefile.target b/Makefile.target
index 6c568b4..be28bfe 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -321,6 +321,7 @@ obj-microblaze-y = petalogix_s3adsp1800_mmu.o
 obj-microblaze-y += petalogix_ml605_mmu.o
 obj-microblaze-y += microblaze_boot.o
 obj-microblaze-y += m25p80.o
+obj-microblaze-y += xilinx_spi.o
 
 obj-microblaze-y += microblaze_pic_cpu.o
 obj-microblaze-y += xilinx_intc.o
diff --git a/hw/xilinx_spi.c b/hw/xilinx_spi.c
new file mode 100644
index 0000000..5e40015
--- /dev/null
+++ b/hw/xilinx_spi.c
@@ -0,0 +1,482 @@
+/*
+ * QEMU model of the Xilinx SPI Controller
+ *
+ * Copyright (C) 2010 Edgar E. Iglesias.
+ * Copyright (C) 2012 Peter A. G. Crosthwaite <address@hidden>
+ * Copyright (C) 2012 PetaLogix
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to 
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "sysbus.h"
+#include "sysemu.h"
+#include "ptimer.h"
+#include "qemu-log.h"
+
+#include "spi.h"
+
+#ifdef XILINX_SPI_ERR_DEBUG
+#define DB_PRINT(...) do { \
+    fprintf(stderr,  ": %s: ", __func__); \
+    fprintf(stderr, ## __VA_ARGS__); \
+    } while (0);
+#else
+    #define DB_PRINT(...)
+#endif
+
+#define R_DGIER     (0x1c / 4)
+#define R_DGIER_IE  (1 << 31)
+
+#define R_IPISR     (0x20 / 4)
+#define IRQ_DRR_NOT_EMPTY    (1 << (31 - 23))
+#define IRQ_DRR_OVERRUN      (1 << (31 - 26))
+#define IRQ_DRR_FULL         (1 << (31 - 27))
+#define IRQ_TX_FF_HALF_EMPTY (1 << 6)
+#define IRQ_DTR_UNDERRUN     (1 << 3)
+#define IRQ_DTR_EMPTY        (1 << (31 - 29))
+
+#define R_IPIER     (0x28 / 4)
+#define R_SRR       (0x40 / 4)
+#define R_SPICR     (0x60 / 4)
+#define R_SPICR_TXFF_RST     (1 << 5)
+#define R_SPICR_RXFF_RST     (1 << 6)
+#define R_SPICR_MTI          (1 << 8)
+
+#define R_SPISR     (0x64 / 4)
+#define SR_TX_FULL    (1 << 3)
+#define SR_TX_EMPTY   (1 << 2)
+#define SR_RX_FULL    (1 << 1)
+#define SR_RX_EMPTY   (1 << 0)
+
+
+#define R_SPIDTR    (0x68 / 4)
+#define R_SPIDRR    (0x6C / 4)
+#define R_SPISSR    (0x70 / 4)
+#define R_TX_FF_OCY (0x74 / 4)
+#define R_RX_FF_OCY (0x78 / 4)
+#define R_MAX       (0x7C / 4)
+
+struct XilinxSPI {
+    SysBusDevice busdev;
+    MemoryRegion mmio;
+    qemu_irq irq;
+    int irqline;
+
+    QEMUBH *bh;
+    ptimer_state *ptimer;
+
+    SPIBus *spi;
+
+    uint32_t c_fifo_exist;
+
+    uint8_t rx_fifo[256];
+    unsigned int rx_fifo_pos;
+    unsigned int rx_fifo_len;
+
+    uint8_t tx_fifo[256];
+    unsigned int tx_fifo_pos;
+    unsigned int tx_fifo_len;
+
+    /* Slave select.  */
+    uint8_t num_cs;
+    int cmd_ongoing;
+
+    uint32_t regs[R_MAX];
+};
+
+static void txfifo_reset(struct XilinxSPI *s)
+{
+    s->tx_fifo_pos = 0;
+    s->tx_fifo_len = 0;
+
+    s->regs[R_SPISR] &= ~SR_TX_FULL;
+    s->regs[R_SPISR] |= SR_TX_EMPTY;
+    s->regs[R_SPISR] &= ~SR_TX_FULL;
+    s->regs[R_IPISR] |= IRQ_DTR_EMPTY;
+}
+
+static void rxfifo_reset(struct XilinxSPI *s)
+{
+    s->rx_fifo_pos = 0;
+    s->rx_fifo_len = 0;
+
+    s->regs[R_SPISR] |= SR_RX_EMPTY;
+    s->regs[R_SPISR] &= ~SR_RX_FULL;
+    s->regs[R_IPISR] &= ~IRQ_DRR_NOT_EMPTY;
+    s->regs[R_IPISR] &= ~IRQ_DRR_OVERRUN;
+}
+
+static void xlx_spi_reset(struct XilinxSPI *s)
+{
+    memset(s->regs, 0, sizeof s->regs);
+
+    rxfifo_reset(s);
+    txfifo_reset(s);
+
+    s->regs[R_SPISSR] = 1;
+    spi_set_cs(s->spi, 0);
+}
+
+static void xlx_spi_update_irq(struct XilinxSPI *s)
+{
+    uint32_t pending;
+    pending = s->regs[R_IPISR] & s->regs[R_IPIER];
+
+    pending = pending && (s->regs[R_DGIER] & R_DGIER_IE);
+    pending = !!pending;
+
+    /* This call lies right in the data paths so dont call the
+       irq chain unless things really changed.  */
+    if (pending != s->irqline) {
+        s->irqline = pending;
+        DB_PRINT("irq_change_of of state %d\n", pending);
+        qemu_set_irq(s->irq, pending);
+    }
+}
+
+static inline int spi_master_enabled(struct XilinxSPI *s)
+{
+    return !(s->regs[R_SPICR] & R_SPICR_MTI);
+}
+
+static int spi_slave_select(struct XilinxSPI *s, uint32_t v)
+{
+    unsigned int ss;
+
+    ss = ffs(v) - 1;
+    return ss < s->num_cs ? ss : SPIBus_NO_CS;
+}
+
+static inline int txfifo_empty(struct XilinxSPI *s)
+{
+    return s->tx_fifo_len == 0;
+}
+
+static inline int txfifo_full(struct XilinxSPI *s)
+{
+    return s->tx_fifo_len >= ARRAY_SIZE(s->tx_fifo);
+}
+
+static inline int rxfifo_empty(struct XilinxSPI *s)
+{
+    return s->rx_fifo_len == 0;
+}
+
+static inline int rxfifo_full(struct XilinxSPI *s)
+{
+    return s->rx_fifo_len >= ARRAY_SIZE(s->rx_fifo);
+}
+
+static inline void txfifo_put(struct XilinxSPI *s, uint8_t v)
+{
+    s->regs[R_SPISR] &= ~SR_TX_EMPTY;
+    s->regs[R_IPISR] &= ~IRQ_DTR_EMPTY;
+
+    s->tx_fifo[s->tx_fifo_pos] = v;
+    s->tx_fifo_pos++;
+    s->tx_fifo_pos &= ARRAY_SIZE(s->tx_fifo) - 1;
+    s->tx_fifo_len++;
+
+    s->regs[R_SPISR] &= ~SR_TX_FULL;
+    if (txfifo_full(s)) {
+        s->regs[R_SPISR] |= SR_TX_FULL;
+    }
+}
+
+static inline uint8_t txfifo_get(struct XilinxSPI *s)
+{
+    uint8_t r = 0;
+    assert(s->tx_fifo_len);
+
+    r = s->tx_fifo[(s->tx_fifo_pos - s->tx_fifo_len) &
+                                (ARRAY_SIZE(s->tx_fifo) - 1)];
+    s->tx_fifo_len--;
+
+    s->regs[R_SPISR] &= ~SR_TX_FULL;
+    if (txfifo_empty(s)) {
+        s->regs[R_SPISR] |= SR_TX_EMPTY;
+        s->regs[R_IPISR] |= IRQ_DTR_EMPTY;
+    }
+
+    return r;
+}
+
+static inline void rxfifo_put(struct XilinxSPI *s, uint8_t v)
+{
+    DB_PRINT("%x\n", v);
+    s->regs[R_SPISR] &= ~SR_RX_EMPTY;
+    s->regs[R_IPISR] |= IRQ_DRR_NOT_EMPTY;
+
+    s->rx_fifo[s->rx_fifo_pos] = v;
+    s->rx_fifo_pos++;
+    s->rx_fifo_pos &= ARRAY_SIZE(s->rx_fifo) - 1;
+    s->rx_fifo_len++;
+
+    s->regs[R_SPISR] &= ~SR_RX_FULL;
+    if (s->rx_fifo_len >= ARRAY_SIZE(s->rx_fifo)) {
+        s->regs[R_SPISR] |= SR_RX_FULL;
+        s->regs[R_IPISR] |= IRQ_DRR_OVERRUN;
+    }
+}
+
+static inline uint32_t rxfifo_get(struct XilinxSPI *s)
+{
+    uint32_t r = 0;
+    assert(s->rx_fifo_len);
+
+    r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) &
+                            (ARRAY_SIZE(s->rx_fifo) - 1)];
+    s->rx_fifo_len--;
+
+    s->regs[R_SPISR] &= ~SR_RX_FULL;
+    if (rxfifo_empty(s)) {
+        s->regs[R_SPISR] |= SR_RX_EMPTY;
+        s->regs[R_IPISR] &= ~IRQ_DRR_NOT_EMPTY;
+    }
+
+    return r;
+}
+
+static void spi_timer_run(struct XilinxSPI *s, int delay)
+{
+    ptimer_set_count(s->ptimer, delay);
+    ptimer_run(s->ptimer, 1);
+}
+
+static void
+spi_flush_txfifo(struct XilinxSPI *s)
+{
+    uint8_t tx;
+    uint8_t txz = 0x00;
+    uint8_t rx;
+    uint8_t rxz = 00;
+
+    while (!txfifo_empty(s)) {
+        tx = txfifo_get(s);
+        DB_PRINT("data transfer:%x\n", tx);
+        if (spi_txrx(s->spi, &tx, &txz, &rx, &rxz, 8)) {
+            hw_error("xilinx spi txrx with no device selected");
+        }
+        if (!rxz) {
+            rxfifo_put(s, rx);
+        } else if (!~rxz) {
+            hw_error("xilinx spi does not support partially tristated 
bytes\n");
+        }
+    }
+}
+
+static uint64_t
+spi_read(void *opaque, target_phys_addr_t addr, unsigned int size)
+{
+    struct XilinxSPI *s = opaque;
+    uint32_t r = 0;
+
+    addr >>= 2;
+    switch (addr) {
+    case R_SPIDRR:
+        if (rxfifo_empty(s)) {
+            DB_PRINT("Read from empty FIFO!\n");
+            return 0xdeadbeef;
+        }
+
+        r = rxfifo_get(s);
+        break;
+
+    case R_SPISR:
+        r = s->regs[addr];
+        if (rxfifo_empty(s)) {
+            spi_timer_run(s, 1);
+        }
+        break;
+
+    default:
+        if (addr < ARRAY_SIZE(s->regs)) {
+            r = s->regs[addr];
+        }
+        break;
+
+    }
+    DB_PRINT("addr=" TARGET_FMT_plx " = %x\n", addr * 4, r);
+    xlx_spi_update_irq(s);
+    return r;
+}
+
+static void
+spi_write(void *opaque, target_phys_addr_t addr,
+            uint64_t val64, unsigned int size)
+{
+    struct XilinxSPI *s = opaque;
+    uint32_t value = val64;
+
+    DB_PRINT("addr=" TARGET_FMT_plx " = %x\n", addr, value);
+    addr >>= 2;
+    switch (addr) {
+    case R_SRR:
+        if (value != 0xa) {
+            DB_PRINT("Invalid write to SRR %x\n", value);
+        } else {
+            xlx_spi_reset(s);
+        }
+        break;
+
+    case R_SPIDTR:
+        txfifo_put(s, value);
+
+        if (!spi_master_enabled(s)) {
+            goto done;
+        } else {
+            DB_PRINT("DTR and master enabled?\n");
+        }
+        spi_flush_txfifo(s);
+        break;
+
+    case R_SPISR:
+        DB_PRINT("Invalid write to SPISR %x\n", value);
+        break;
+
+    case R_IPISR:
+        /* Toggle the bits.  */
+        s->regs[addr] ^= value;
+        break;
+
+    /* Slave Select Register.  */
+    case R_SPISSR:
+        spi_set_cs(s->spi, spi_slave_select(s, ~value));
+        s->regs[addr] = value;
+        break;
+
+    case R_SPICR:
+        /* FIXME: reset irq and sr state to empty queues.  */
+        if (value & R_SPICR_RXFF_RST) {
+            rxfifo_reset(s);
+        }
+
+        if (value & R_SPICR_TXFF_RST) {
+            txfifo_reset(s);
+        }
+        value &= ~(R_SPICR_RXFF_RST | R_SPICR_TXFF_RST);
+        s->regs[addr] = value;
+
+        if (!(value & R_SPICR_MTI)) {
+            /*
+             * The linux driver, when issuing READS to a flash memory,
+             * first sets up the tx part, starts the transmition and
+             * waits for the tx part to end. After that it sets up
+             * the rx part, assumeing the CPU is faster than the flash.
+             *
+             * If we simply flush the txfifo and consume all rx data
+             * from the flash, we'll hit a race in the linux driver and
+             * some rx data will be arrive to the linux driver too early.
+             *
+             * That's why we implement this hack. If we are at the start
+             * of a new cmd (i.e s->cmd_ongoing == 0), then we delay
+             * the processing a bit, to give linux time to set things
+             * up.
+             *
+             * FIXME: The mentione hack doesn't work. Investigate why.
+             */
+            if (0 && s->cmd_ongoing) {
+                spi_flush_txfifo(s);
+            } else {
+                /* When releasing the master disable, initiate a timer
+                   that eventually will flush the txfifo.  */
+                spi_timer_run(s, 1);
+            }
+        }
+        break;
+
+    default:
+        if (addr < ARRAY_SIZE(s->regs)) {
+            s->regs[addr] = value;
+        }
+        break;
+    }
+
+done:
+    xlx_spi_update_irq(s);
+}
+
+static const MemoryRegionOps spi_ops = {
+    .read = spi_read,
+    .write = spi_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4
+    }
+};
+
+static void timer_hit(void *opaque)
+{
+    struct XilinxSPI *s = opaque;
+
+    if (!txfifo_empty(s)) {
+        spi_flush_txfifo(s);
+        s->cmd_ongoing = 1;
+    }
+    xlx_spi_update_irq(s);
+}
+
+static int xilinx_spi_init(SysBusDevice *dev)
+{
+    struct XilinxSPI *s = FROM_SYSBUS(typeof(*s), dev);
+
+    DB_PRINT("\n");
+    sysbus_init_irq(dev, &s->irq);
+
+    memory_region_init_io(&s->mmio, &spi_ops, s, "xilinx-spi", R_MAX * 4);
+    sysbus_init_mmio(dev, &s->mmio);
+
+    s->bh = qemu_bh_new(timer_hit, s);
+    s->ptimer = ptimer_init(s->bh);
+    ptimer_set_freq(s->ptimer, 10 * 1000 * 1000);
+
+    s->spi = spi_init_bus(&dev->qdev, s->num_cs, "spi");
+
+    xlx_spi_reset(s);
+    return 0;
+}
+
+static Property xilinx_spi_properties[] = {
+    DEFINE_PROP_UINT8("num-cs", struct XilinxSPI, num_cs, 1),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void xilinx_spi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = xilinx_spi_init;
+    dc->props = xilinx_spi_properties;
+}
+
+static TypeInfo xilinx_spi_info = {
+    .name           = "xilinx,spi",
+    .parent         = TYPE_SYS_BUS_DEVICE,
+    .instance_size  = sizeof(struct XilinxSPI),
+    .class_init     = xilinx_spi_class_init,
+};
+
+static void xilinx_spi_register_types(void)
+{
+    type_register_static(&xilinx_spi_info);
+}
+
+type_init(xilinx_spi_register_types)
-- 
1.7.3.2