spi/mpc5121: Add SPI master driver for MPC5121 PSC

Signed-off-by: John Rigby <jcrigby@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 576 insertions, 0 deletions

diff --git a/drivers/spi/mpc512x_psc_spi.c b/drivers/spi/mpc512x_psc_spi.c
new file mode 100644
index 000000000000..28a126d2742b
--- /dev/null
+++ b/drivers/spi/mpc512x_psc_spi.c
@@ -0,0 +1,576 @@
+/*
+ * MPC512x PSC in SPI mode driver.
+ *
+ * Copyright (C) 2007,2008 Freescale Semiconductor Inc.
+ * Original port from 52xx driver:
+ *      Hongjun Chen <hong-jun.chen@freescale.com>
+ *
+ * Fork of mpc52xx_psc_spi.c:
+ *      Copyright (C) 2006 TOPTICA Photonics AG., Dragos Carp
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/of_platform.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/spi/spi.h>
+#include <linux/fsl_devices.h>
+#include <asm/mpc52xx_psc.h>
+
+struct mpc512x_psc_spi {
+        void (*cs_control)(struct spi_device *spi, bool on);
+        u32 sysclk;
+
+        /* driver internal data */
+        struct mpc52xx_psc __iomem *psc;
+        struct mpc512x_psc_fifo __iomem *fifo;
+        unsigned int irq;
+        u8 bits_per_word;
+        u8 busy;
+        u32 mclk;
+        u8 eofbyte;
+
+        struct workqueue_struct *workqueue;
+        struct work_struct work;
+
+        struct list_head queue;
+        spinlock_t lock;        /* Message queue lock */
+
+        struct completion done;
+};
+
+/* controller state */
+struct mpc512x_psc_spi_cs {
+        int bits_per_word;
+        int speed_hz;
+};
+
+/* set clock freq, clock ramp, bits per work
+ * if t is NULL then reset the values to the default values
+ */
+static int mpc512x_psc_spi_transfer_setup(struct spi_device *spi,
+                                          struct spi_transfer *t)
+{
+        struct mpc512x_psc_spi_cs *cs = spi->controller_state;
+
+        cs->speed_hz = (t && t->speed_hz)
+            ? t->speed_hz : spi->max_speed_hz;
+        cs->bits_per_word = (t && t->bits_per_word)
+            ? t->bits_per_word : spi->bits_per_word;
+        cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8;
+        return 0;
+}
+
+static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
+{
+        struct mpc512x_psc_spi_cs *cs = spi->controller_state;
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+        struct mpc52xx_psc __iomem *psc = mps->psc;
+        u32 sicr;
+        u32 ccr;
+        u16 bclkdiv;
+
+        sicr = in_be32(&psc->sicr);
+
+        /* Set clock phase and polarity */
+        if (spi->mode & SPI_CPHA)
+                sicr |= 0x00001000;
+        else
+                sicr &= ~0x00001000;
+
+        if (spi->mode & SPI_CPOL)
+                sicr |= 0x00002000;
+        else
+                sicr &= ~0x00002000;
+
+        if (spi->mode & SPI_LSB_FIRST)
+                sicr |= 0x10000000;
+        else
+                sicr &= ~0x10000000;
+        out_be32(&psc->sicr, sicr);
+
+        ccr = in_be32(&psc->ccr);
+        ccr &= 0xFF000000;
+        if (cs->speed_hz)
+                bclkdiv = (mps->mclk / cs->speed_hz) - 1;
+        else
+                bclkdiv = (mps->mclk / 1000000) - 1;    /* default 1MHz */
+
+        ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8));
+        out_be32(&psc->ccr, ccr);
+        mps->bits_per_word = cs->bits_per_word;
+
+        if (mps->cs_control)
+                mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
+}
+
+static void mpc512x_psc_spi_deactivate_cs(struct spi_device *spi)
+{
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+
+        if (mps->cs_control)
+                mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
+
+}
+
+/* extract and scale size field in txsz or rxsz */
+#define MPC512x_PSC_FIFO_SZ(sz) ((sz & 0x7ff) << 2);
+
+#define EOFBYTE 1
+
+static int mpc512x_psc_spi_transfer_rxtx(struct spi_device *spi,
+                                         struct spi_transfer *t)
+{
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+        struct mpc52xx_psc __iomem *psc = mps->psc;
+        struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
+        size_t len = t->len;
+        u8 *tx_buf = (u8 *)t->tx_buf;
+        u8 *rx_buf = (u8 *)t->rx_buf;
+
+        if (!tx_buf && !rx_buf && t->len)
+                return -EINVAL;
+
+        /* Zero MR2 */
+        in_8(&psc->mode);
+        out_8(&psc->mode, 0x0);
+
+        while (len) {
+                int count;
+                int i;
+                u8 data;
+                size_t fifosz;
+                int rxcount;
+
+                /*
+                 * The number of bytes that can be sent at a time
+                 * depends on the fifo size.
+                 */
+                fifosz = MPC512x_PSC_FIFO_SZ(in_be32(&fifo->txsz));
+                count = min(fifosz, len);
+
+                for (i = count; i > 0; i--) {
+                        data = tx_buf ? *tx_buf++ : 0;
+                        if (len == EOFBYTE)
+                                setbits32(&fifo->txcmd, MPC512x_PSC_FIFO_EOF);
+                        out_8(&fifo->txdata_8, data);
+                        len--;
+                }
+
+                INIT_COMPLETION(mps->done);
+
+                /* interrupt on tx fifo empty */
+                out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY);
+                out_be32(&fifo->tximr, MPC512x_PSC_FIFO_EMPTY);
+
+                /* enable transmiter/receiver */
+                out_8(&psc->command,
+                      MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
+
+                wait_for_completion(&mps->done);
+
+                mdelay(1);
+
+                /* rx fifo should have count bytes in it */
+                rxcount = in_be32(&fifo->rxcnt);
+                if (rxcount != count)
+                        mdelay(1);
+
+                rxcount = in_be32(&fifo->rxcnt);
+                if (rxcount != count) {
+                        dev_warn(&spi->dev, "expected %d bytes in rx fifo "
+                                 "but got %d\n", count, rxcount);
+                }
+
+                rxcount = min(rxcount, count);
+                for (i = rxcount; i > 0; i--) {
+                        data = in_8(&fifo->rxdata_8);
+                        if (rx_buf)
+                                *rx_buf++ = data;
+                }
+                while (in_be32(&fifo->rxcnt)) {
+                        in_8(&fifo->rxdata_8);
+                }
+
+                out_8(&psc->command,
+                      MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+        }
+        /* disable transmiter/receiver and fifo interrupt */
+        out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+        out_be32(&fifo->tximr, 0);
+        return 0;
+}
+
+static void mpc512x_psc_spi_work(struct work_struct *work)
+{
+        struct mpc512x_psc_spi *mps = container_of(work,
+                                                   struct mpc512x_psc_spi,
+                                                   work);
+
+        spin_lock_irq(&mps->lock);
+        mps->busy = 1;
+        while (!list_empty(&mps->queue)) {
+                struct spi_message *m;
+                struct spi_device *spi;
+                struct spi_transfer *t = NULL;
+                unsigned cs_change;
+                int status;
+
+                m = container_of(mps->queue.next, struct spi_message, queue);
+                list_del_init(&m->queue);
+                spin_unlock_irq(&mps->lock);
+
+                spi = m->spi;
+                cs_change = 1;
+                status = 0;
+                list_for_each_entry(t, &m->transfers, transfer_list) {
+                        if (t->bits_per_word || t->speed_hz) {
+                                status = mpc512x_psc_spi_transfer_setup(spi, t);
+                                if (status < 0)
+                                        break;
+                        }
+
+                        if (cs_change)
+                                mpc512x_psc_spi_activate_cs(spi);
+                        cs_change = t->cs_change;
+
+                        status = mpc512x_psc_spi_transfer_rxtx(spi, t);
+                        if (status)
+                                break;
+                        m->actual_length += t->len;
+
+                        if (t->delay_usecs)
+                                udelay(t->delay_usecs);
+
+                        if (cs_change)
+                                mpc512x_psc_spi_deactivate_cs(spi);
+                }
+
+                m->status = status;
+                m->complete(m->context);
+
+                if (status || !cs_change)
+                        mpc512x_psc_spi_deactivate_cs(spi);
+
+                mpc512x_psc_spi_transfer_setup(spi, NULL);
+
+                spin_lock_irq(&mps->lock);
+        }
+        mps->busy = 0;
+        spin_unlock_irq(&mps->lock);
+}
+
+static int mpc512x_psc_spi_setup(struct spi_device *spi)
+{
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+        struct mpc512x_psc_spi_cs *cs = spi->controller_state;
+        unsigned long flags;
+
+        if (spi->bits_per_word % 8)
+                return -EINVAL;
+
+        if (!cs) {
+                cs = kzalloc(sizeof *cs, GFP_KERNEL);
+                if (!cs)
+                        return -ENOMEM;
+                spi->controller_state = cs;
+        }
+
+        cs->bits_per_word = spi->bits_per_word;
+        cs->speed_hz = spi->max_speed_hz;
+
+        spin_lock_irqsave(&mps->lock, flags);
+        if (!mps->busy)
+                mpc512x_psc_spi_deactivate_cs(spi);
+        spin_unlock_irqrestore(&mps->lock, flags);
+
+        return 0;
+}
+
+static int mpc512x_psc_spi_transfer(struct spi_device *spi,
+                                    struct spi_message *m)
+{
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
+        unsigned long flags;
+
+        m->actual_length = 0;
+        m->status = -EINPROGRESS;
+
+        spin_lock_irqsave(&mps->lock, flags);
+        list_add_tail(&m->queue, &mps->queue);
+        queue_work(mps->workqueue, &mps->work);
+        spin_unlock_irqrestore(&mps->lock, flags);
+
+        return 0;
+}
+
+static void mpc512x_psc_spi_cleanup(struct spi_device *spi)
+{
+        kfree(spi->controller_state);
+}
+
+static int mpc512x_psc_spi_port_config(struct spi_master *master,
+                                       struct mpc512x_psc_spi *mps)
+{
+        struct mpc52xx_psc __iomem *psc = mps->psc;
+        struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
+        struct clk *spiclk;
+        int ret = 0;
+        char name[32];
+        u32 sicr;
+        u32 ccr;
+        u16 bclkdiv;
+
+        sprintf(name, "psc%d_mclk", master->bus_num);
+        spiclk = clk_get(&master->dev, name);
+        clk_enable(spiclk);
+        mps->mclk = clk_get_rate(spiclk);
+        clk_put(spiclk);
+
+        /* Reset the PSC into a known state */
+        out_8(&psc->command, MPC52xx_PSC_RST_RX);
+        out_8(&psc->command, MPC52xx_PSC_RST_TX);
+        out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+
+        /* Disable psc interrupts all useful interrupts are in fifo */
+        out_be16(&psc->isr_imr.imr, 0);
+
+        /* Disable fifo interrupts, will be enabled later */
+        out_be32(&fifo->tximr, 0);
+        out_be32(&fifo->rximr, 0);
+
+        /* Setup fifo slice address and size */
+        /*out_be32(&fifo->txsz, 0x0fe00004);*/
+        /*out_be32(&fifo->rxsz, 0x0ff00004);*/
+
+        sicr =  0x01000000 |    /* SIM = 0001 -- 8 bit */
+                0x00800000 |    /* GenClk = 1 -- internal clk */
+                0x00008000 |    /* SPI = 1 */
+                0x00004000 |    /* MSTR = 1   -- SPI master */
+                0x00000800;     /* UseEOF = 1 -- SS low until EOF */
+
+        out_be32(&psc->sicr, sicr);
+
+        ccr = in_be32(&psc->ccr);
+        ccr &= 0xFF000000;
+        bclkdiv = (mps->mclk / 1000000) - 1;    /* default 1MHz */
+        ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8));
+        out_be32(&psc->ccr, ccr);
+
+        /* Set 2ms DTL delay */
+        out_8(&psc->ctur, 0x00);
+        out_8(&psc->ctlr, 0x82);
+
+        /* we don't use the alarms */
+        out_be32(&fifo->rxalarm, 0xfff);
+        out_be32(&fifo->txalarm, 0);
+
+        /* Enable FIFO slices for Rx/Tx */
+        out_be32(&fifo->rxcmd,
+                 MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA);
+        out_be32(&fifo->txcmd,
+                 MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA);
+
+        mps->bits_per_word = 8;
+
+        return ret;
+}
+
+static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id)
+{
+        struct mpc512x_psc_spi *mps = (struct mpc512x_psc_spi *)dev_id;
+        struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
+
+        /* clear interrupt and wake up the work queue */
+        if (in_be32(&fifo->txisr) &
+            in_be32(&fifo->tximr) & MPC512x_PSC_FIFO_EMPTY) {
+                out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY);
+                out_be32(&fifo->tximr, 0);
+                complete(&mps->done);
+                return IRQ_HANDLED;
+        }
+        return IRQ_NONE;
+}
+
+/* bus_num is used only for the case dev->platform_data == NULL */
+static int __init mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
+                                           u32 size, unsigned int irq,
+                                           s16 bus_num)
+{
+        struct fsl_spi_platform_data *pdata = dev->platform_data;
+        struct mpc512x_psc_spi *mps;
+        struct spi_master *master;
+        int ret;
+        void *tempp;
+
+        master = spi_alloc_master(dev, sizeof *mps);
+        if (master == NULL)
+                return -ENOMEM;
+
+        dev_set_drvdata(dev, master);
+        mps = spi_master_get_devdata(master);
+        mps->irq = irq;
+
+        if (pdata == NULL) {
+                dev_err(dev, "probe called without platform data, no "
+                        "cs_control function will be called\n");
+                mps->cs_control = NULL;
+                mps->sysclk = 0;
+                master->bus_num = bus_num;
+                master->num_chipselect = 255;
+        } else {
+                mps->cs_control = pdata->cs_control;
+                mps->sysclk = pdata->sysclk;
+                master->bus_num = pdata->bus_num;
+                master->num_chipselect = pdata->max_chipselect;
+        }
+
+        master->setup = mpc512x_psc_spi_setup;
+        master->transfer = mpc512x_psc_spi_transfer;
+        master->cleanup = mpc512x_psc_spi_cleanup;
+
+        tempp = ioremap(regaddr, size);
+        if (!tempp) {
+                dev_err(dev, "could not ioremap I/O port range\n");
+                ret = -EFAULT;
+                goto free_master;
+        }
+        mps->psc = tempp;
+        mps->fifo =
+                (struct mpc512x_psc_fifo *)(tempp + sizeof(struct mpc52xx_psc));
+
+        ret = request_irq(mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED,
+                          "mpc512x-psc-spi", mps);
+        if (ret)
+                goto free_master;
+
+        ret = mpc512x_psc_spi_port_config(master, mps);
+        if (ret < 0)
+                goto free_irq;
+
+        spin_lock_init(&mps->lock);
+        init_completion(&mps->done);
+        INIT_WORK(&mps->work, mpc512x_psc_spi_work);
+        INIT_LIST_HEAD(&mps->queue);
+
+        mps->workqueue =
+                create_singlethread_workqueue(dev_name(master->dev.parent));
+        if (mps->workqueue == NULL) {
+                ret = -EBUSY;
+                goto free_irq;
+        }
+
+        ret = spi_register_master(master);
+        if (ret < 0)
+                goto unreg_master;
+
+        return ret;
+
+unreg_master:
+        destroy_workqueue(mps->workqueue);
+free_irq:
+        free_irq(mps->irq, mps);
+free_master:
+        if (mps->psc)
+                iounmap(mps->psc);
+        spi_master_put(master);
+
+        return ret;
+}
+
+static int __exit mpc512x_psc_spi_do_remove(struct device *dev)
+{
+        struct spi_master *master = dev_get_drvdata(dev);
+        struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
+
+        flush_workqueue(mps->workqueue);
+        destroy_workqueue(mps->workqueue);
+        spi_unregister_master(master);
+        free_irq(mps->irq, mps);
+        if (mps->psc)
+                iounmap(mps->psc);
+
+        return 0;
+}
+
+static int __init mpc512x_psc_spi_of_probe(struct of_device *op,
+                                           const struct of_device_id *match)
+{
+        const u32 *regaddr_p;
+        u64 regaddr64, size64;
+        s16 id = -1;
+
+        regaddr_p = of_get_address(op->node, 0, &size64, NULL);
+        if (!regaddr_p) {
+                dev_err(&op->dev, "Invalid PSC address\n");
+                return -EINVAL;
+        }
+        regaddr64 = of_translate_address(op->node, regaddr_p);
+
+        /* get PSC id (0..11, used by port_config) */
+        if (op->dev.platform_data == NULL) {
+                const u32 *psc_nump;
+
+                psc_nump = of_get_property(op->node, "cell-index", NULL);
+                if (!psc_nump || *psc_nump > 11) {
+                        dev_err(&op->dev, "mpc512x_psc_spi: Device node %s "
+                                "has invalid cell-index property\n",
+                                op->node->full_name);
+                        return -EINVAL;
+                }
+                id = *psc_nump;
+        }
+
+        return mpc512x_psc_spi_do_probe(&op->dev, (u32) regaddr64, (u32) size64,
+                                        irq_of_parse_and_map(op->node, 0), id);
+}
+
+static int __exit mpc512x_psc_spi_of_remove(struct of_device *op)
+{
+        return mpc512x_psc_spi_do_remove(&op->dev);
+}
+
+static struct of_device_id mpc512x_psc_spi_of_match[] = {
+        { .compatible = "fsl,mpc5121-psc-spi", },
+        {},
+};
+
+MODULE_DEVICE_TABLE(of, mpc512x_psc_spi_of_match);
+
+static struct of_platform_driver mpc512x_psc_spi_of_driver = {
+        .match_table = mpc512x_psc_spi_of_match,
+        .probe = mpc512x_psc_spi_of_probe,
+        .remove = __exit_p(mpc512x_psc_spi_of_remove),
+        .driver = {
+                .name = "mpc512x-psc-spi",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init mpc512x_psc_spi_init(void)
+{
+        return of_register_platform_driver(&mpc512x_psc_spi_of_driver);
+}
+module_init(mpc512x_psc_spi_init);
+
+static void __exit mpc512x_psc_spi_exit(void)
+{
+        of_unregister_platform_driver(&mpc512x_psc_spi_of_driver);
+}
+module_exit(mpc512x_psc_spi_exit);
+
+MODULE_AUTHOR("John Rigby");
+MODULE_DESCRIPTION("MPC512x PSC SPI Driver");
+MODULE_LICENSE("GPL");