3 files changed, 496 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 9ce1d01469b1..3867c6ef24f3 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -75,6 +75,18 @@ config SPI_BUTTERFLY
           inexpensive battery powered microcontroller evaluation board.
           This same cable can be used to flash new firmware.
 
+config SPI_MPC83xx
+        tristate "Freescale MPC83xx SPI controller"
+        depends on SPI_MASTER && PPC_83xx && EXPERIMENTAL
+        select SPI_BITBANG
+        help
+          This enables using the Freescale MPC83xx SPI controller in master
+          mode.
+
+          Note, this driver uniquely supports the SPI controller on the MPC83xx
+          family of PowerPC processors.  The MPC83xx uses a simple set of shift
+          registers for data (opposed to the CPM based descriptor model).
+
 config SPI_PXA2XX
         tristate "PXA2xx SSP SPI master"
         depends on SPI_MASTER && ARCH_PXA && EXPERIMENTAL
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 1bca5f95de25..5a410caa03c7 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_SPI_MASTER)		+= spi.o
 obj-$(CONFIG_SPI_BITBANG)               += spi_bitbang.o
 obj-$(CONFIG_SPI_BUTTERFLY)             += spi_butterfly.o
 obj-$(CONFIG_SPI_PXA2XX)                += pxa2xx_spi.o
+obj-$(CONFIG_SPI_MPC83xx)               += spi_mpc83xx.o
 #       ... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
new file mode 100644
index 000000000000..5d92a7e5cb41
--- /dev/null
+++ b/drivers/spi/spi_mpc83xx.c
@@ -0,0 +1,483 @@
+/*
+ * MPC83xx SPI controller driver.
+ *
+ * Maintainer: Kumar Gala
+ *
+ * Copyright (C) 2006 Polycom, Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/platform_device.h>
+#include <linux/fsl_devices.h>
+
+#include <asm/irq.h>
+#include <asm/io.h>
+
+/* SPI Controller registers */
+struct mpc83xx_spi_reg {
+        u8 res1[0x20];
+        __be32 mode;
+        __be32 event;
+        __be32 mask;
+        __be32 command;
+        __be32 transmit;
+        __be32 receive;
+};
+
+/* SPI Controller mode register definitions */
+#define SPMODE_CI_INACTIVEHIGH  (1 << 29)
+#define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
+#define SPMODE_DIV16            (1 << 27)
+#define SPMODE_REV              (1 << 26)
+#define SPMODE_MS               (1 << 25)
+#define SPMODE_ENABLE           (1 << 24)
+#define SPMODE_LEN(x)           ((x) << 20)
+#define SPMODE_PM(x)            ((x) << 16)
+
+/*
+ * Default for SPI Mode:
+ *      SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
+ */
+#define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
+                         SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
+
+/* SPIE register values */
+#define SPIE_NE         0x00000200      /* Not empty */
+#define SPIE_NF         0x00000100      /* Not full */
+
+/* SPIM register values */
+#define SPIM_NE         0x00000200      /* Not empty */
+#define SPIM_NF         0x00000100      /* Not full */
+
+/* SPI Controller driver's private data. */
+struct mpc83xx_spi {
+        /* bitbang has to be first */
+        struct spi_bitbang bitbang;
+        struct completion done;
+
+        struct mpc83xx_spi_reg __iomem *base;
+
+        /* rx & tx bufs from the spi_transfer */
+        const void *tx;
+        void *rx;
+
+        /* functions to deal with different sized buffers */
+        void (*get_rx) (u32 rx_data, struct mpc83xx_spi *);
+        u32(*get_tx) (struct mpc83xx_spi *);
+
+        unsigned int count;
+        u32 irq;
+
+        unsigned nsecs;         /* (clock cycle time)/2 */
+
+        u32 sysclk;
+        void (*activate_cs) (u8 cs, u8 polarity);
+        void (*deactivate_cs) (u8 cs, u8 polarity);
+};
+
+static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val)
+{
+        out_be32(reg, val);
+}
+
+static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
+{
+        return in_be32(reg);
+}
+
+#define MPC83XX_SPI_RX_BUF(type)                                          \
+void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
+{                                                                         \
+        type * rx = mpc83xx_spi->rx;                                      \
+        *rx++ = (type)data;                                               \
+        mpc83xx_spi->rx = rx;                                             \
+}
+
+#define MPC83XX_SPI_TX_BUF(type)                                \
+u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi)  \
+{                                                               \
+        u32 data;                                               \
+        const type * tx = mpc83xx_spi->tx;                      \
+        data = *tx++;                                           \
+        mpc83xx_spi->tx = tx;                                   \
+        return data;                                            \
+}
+
+MPC83XX_SPI_RX_BUF(u8)
+MPC83XX_SPI_RX_BUF(u16)
+MPC83XX_SPI_RX_BUF(u32)
+MPC83XX_SPI_TX_BUF(u8)
+MPC83XX_SPI_TX_BUF(u16)
+MPC83XX_SPI_TX_BUF(u32)
+
+static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
+{
+        struct mpc83xx_spi *mpc83xx_spi;
+        u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0;
+
+        mpc83xx_spi = spi_master_get_devdata(spi->master);
+
+        if (value == BITBANG_CS_INACTIVE) {
+                if (mpc83xx_spi->deactivate_cs)
+                        mpc83xx_spi->deactivate_cs(spi->chip_select, pol);
+        }
+
+        if (value == BITBANG_CS_ACTIVE) {
+                u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
+                u32 len = spi->bits_per_word;
+                if (len == 32)
+                        len = 0;
+                else
+                        len = len - 1;
+
+                /* mask out bits we are going to set */
+                regval &= ~0x38ff0000;
+
+                if (spi->mode & SPI_CPHA)
+                        regval |= SPMODE_CP_BEGIN_EDGECLK;
+                if (spi->mode & SPI_CPOL)
+                        regval |= SPMODE_CI_INACTIVEHIGH;
+
+                regval |= SPMODE_LEN(len);
+
+                if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) {
+                        u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64);
+                        regval |= SPMODE_PM(pm) | SPMODE_DIV16;
+                } else {
+                        u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
+                        regval |= SPMODE_PM(pm);
+                }
+
+                mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
+                if (mpc83xx_spi->activate_cs)
+                        mpc83xx_spi->activate_cs(spi->chip_select, pol);
+        }
+}
+
+static
+int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+        struct mpc83xx_spi *mpc83xx_spi;
+        u32 regval;
+        u8 bits_per_word;
+        u32 hz;
+
+        mpc83xx_spi = spi_master_get_devdata(spi->master);
+
+        if (t) {
+                bits_per_word = t->bits_per_word;
+                hz = t->speed_hz;
+        } else {
+                bits_per_word = 0;
+                hz = 0;
+        }
+
+        /* spi_transfer level calls that work per-word */
+        if (!bits_per_word)
+                bits_per_word = spi->bits_per_word;
+
+        /* Make sure its a bit width we support [4..16, 32] */
+        if ((bits_per_word < 4)
+            || ((bits_per_word > 16) && (bits_per_word != 32)))
+                return -EINVAL;
+
+        if (bits_per_word <= 8) {
+                mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
+                mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
+        } else if (bits_per_word <= 16) {
+                mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
+                mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
+        } else if (bits_per_word <= 32) {
+                mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
+                mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
+        } else
+                return -EINVAL;
+
+        /* nsecs = (clock period)/2 */
+        if (!hz)
+                hz = spi->max_speed_hz;
+        mpc83xx_spi->nsecs = (1000000000 / 2) / hz;
+        if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000)
+                return -EINVAL;
+
+        if (bits_per_word == 32)
+                bits_per_word = 0;
+        else
+                bits_per_word = bits_per_word - 1;
+
+        regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
+
+        /* Mask out bits_per_wordgth */
+        regval &= 0xff0fffff;
+        regval |= SPMODE_LEN(bits_per_word);
+
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
+
+        return 0;
+}
+
+static int mpc83xx_spi_setup(struct spi_device *spi)
+{
+        struct spi_bitbang *bitbang;
+        struct mpc83xx_spi *mpc83xx_spi;
+        int retval;
+
+        if (!spi->max_speed_hz)
+                return -EINVAL;
+
+        bitbang = spi_master_get_devdata(spi->master);
+        mpc83xx_spi = spi_master_get_devdata(spi->master);
+
+        if (!spi->bits_per_word)
+                spi->bits_per_word = 8;
+
+        retval = mpc83xx_spi_setup_transfer(spi, NULL);
+        if (retval < 0)
+                return retval;
+
+        dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
+                __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
+                spi->bits_per_word, 2 * mpc83xx_spi->nsecs);
+
+        /* NOTE we _need_ to call chipselect() early, ideally with adapter
+         * setup, unless the hardware defaults cooperate to avoid confusion
+         * between normal (active low) and inverted chipselects.
+         */
+
+        /* deselect chip (low or high) */
+        spin_lock(&bitbang->lock);
+        if (!bitbang->busy) {
+                bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
+                ndelay(mpc83xx_spi->nsecs);
+        }
+        spin_unlock(&bitbang->lock);
+
+        return 0;
+}
+
+static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+        struct mpc83xx_spi *mpc83xx_spi;
+        u32 word;
+
+        mpc83xx_spi = spi_master_get_devdata(spi->master);
+
+        mpc83xx_spi->tx = t->tx_buf;
+        mpc83xx_spi->rx = t->rx_buf;
+        mpc83xx_spi->count = t->len;
+        INIT_COMPLETION(mpc83xx_spi->done);
+
+        /* enable rx ints */
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);
+
+        /* transmit word */
+        word = mpc83xx_spi->get_tx(mpc83xx_spi);
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
+
+        wait_for_completion(&mpc83xx_spi->done);
+
+        /* disable rx ints */
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
+
+        return t->len - mpc83xx_spi->count;
+}
+
+irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data,
+                            struct pt_regs * ptregs)
+{
+        struct mpc83xx_spi *mpc83xx_spi = context_data;
+        u32 event;
+        irqreturn_t ret = IRQ_NONE;
+
+        /* Get interrupt events(tx/rx) */
+        event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);
+
+        /* We need handle RX first */
+        if (event & SPIE_NE) {
+                u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);
+
+                if (mpc83xx_spi->rx)
+                        mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);
+
+                ret = IRQ_HANDLED;
+        }
+
+        if ((event & SPIE_NF) == 0)
+                /* spin until TX is done */
+                while (((event =
+                         mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
+                                                SPIE_NF) == 0)
+                         cpu_relax();
+
+        mpc83xx_spi->count -= 1;
+        if (mpc83xx_spi->count) {
+                if (mpc83xx_spi->tx) {
+                        u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
+                        mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
+                                              word);
+                }
+        } else {
+                complete(&mpc83xx_spi->done);
+        }
+
+        /* Clear the events */
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);
+
+        return ret;
+}
+
+static int __init mpc83xx_spi_probe(struct platform_device *dev)
+{
+        struct spi_master *master;
+        struct mpc83xx_spi *mpc83xx_spi;
+        struct fsl_spi_platform_data *pdata;
+        struct resource *r;
+        u32 regval;
+        int ret = 0;
+
+        /* Get resources(memory, IRQ) associated with the device */
+        master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));
+
+        if (master == NULL) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        platform_set_drvdata(dev, master);
+        pdata = dev->dev.platform_data;
+
+        if (pdata == NULL) {
+                ret = -ENODEV;
+                goto free_master;
+        }
+
+        r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+        if (r == NULL) {
+                ret = -ENODEV;
+                goto free_master;
+        }
+
+        mpc83xx_spi = spi_master_get_devdata(master);
+        mpc83xx_spi->bitbang.master = spi_master_get(master);
+        mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
+        mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
+        mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
+        mpc83xx_spi->sysclk = pdata->sysclk;
+        mpc83xx_spi->activate_cs = pdata->activate_cs;
+        mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
+        mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
+        mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
+
+        mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
+        init_completion(&mpc83xx_spi->done);
+
+        mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
+        if (mpc83xx_spi->base == NULL) {
+                ret = -ENOMEM;
+                goto put_master;
+        }
+
+        mpc83xx_spi->irq = platform_get_irq(dev, 0);
+
+        if (mpc83xx_spi->irq < 0) {
+                ret = -ENXIO;
+                goto unmap_io;
+        }
+
+        /* Register for SPI Interrupt */
+        ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
+                          0, "mpc83xx_spi", mpc83xx_spi);
+
+        if (ret != 0)
+                goto unmap_io;
+
+        master->bus_num = pdata->bus_num;
+        master->num_chipselect = pdata->max_chipselect;
+
+        /* SPI controller initializations */
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);
+
+        /* Enable SPI interface */
+        regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
+        mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
+
+        ret = spi_bitbang_start(&mpc83xx_spi->bitbang);
+
+        if (ret != 0)
+                goto free_irq;
+
+        printk(KERN_INFO
+               "%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
+               dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq);
+
+        return ret;
+
+free_irq:
+        free_irq(mpc83xx_spi->irq, mpc83xx_spi);
+unmap_io:
+        iounmap(mpc83xx_spi->base);
+put_master:
+        spi_master_put(master);
+free_master:
+        kfree(master);
+err:
+        return ret;
+}
+
+static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
+{
+        struct mpc83xx_spi *mpc83xx_spi;
+        struct spi_master *master;
+
+        master = platform_get_drvdata(dev);
+        mpc83xx_spi = spi_master_get_devdata(master);
+
+        spi_bitbang_stop(&mpc83xx_spi->bitbang);
+        free_irq(mpc83xx_spi->irq, mpc83xx_spi);
+        iounmap(mpc83xx_spi->base);
+        spi_master_put(mpc83xx_spi->bitbang.master);
+
+        return 0;
+}
+
+static struct platform_driver mpc83xx_spi_driver = {
+        .probe = mpc83xx_spi_probe,
+        .remove = __devexit_p(mpc83xx_spi_remove),
+        .driver = {
+                   .name = "mpc83xx_spi",
+        },
+};
+
+static int __init mpc83xx_spi_init(void)
+{
+        return platform_driver_register(&mpc83xx_spi_driver);
+}
+
+static void __exit mpc83xx_spi_exit(void)
+{
+        platform_driver_unregister(&mpc83xx_spi_driver);
+}
+
+module_init(mpc83xx_spi_init);
+module_exit(mpc83xx_spi_exit);
+
+MODULE_AUTHOR("Kumar Gala");
+MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
+MODULE_LICENSE("GPL");