--- /dev/null
+/*
+ * MPC52xx PSC in SPI mode driver.
+ *
+ * Maintainer: Dragos Carp
+ *
+ * Copyright (C) 2006 TOPTICA Photonics AG.
+ *
+ * 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/types.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/fsl_devices.h>
+#include <linux/slab.h>
+
+#include <asm/mpc52xx.h>
+#include <asm/mpc52xx_psc.h>
+
+#define MCLK 20000000 /* PSC port MClk in hz */
+
+struct mpc52xx_psc_spi {
+ /* fsl_spi_platform data */
+ void (*cs_control)(struct spi_device *spi, bool on);
+ u32 sysclk;
+
+ /* driver internal data */
+ struct mpc52xx_psc __iomem *psc;
+ struct mpc52xx_psc_fifo __iomem *fifo;
+ unsigned int irq;
+ u8 bits_per_word;
+ u8 busy;
+
+ struct workqueue_struct *workqueue;
+ struct work_struct work;
+
+ struct list_head queue;
+ spinlock_t lock;
+
+ struct completion done;
+};
+
+/* controller state */
+struct mpc52xx_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 mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct mpc52xx_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 mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
+{
+ struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
+ struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+ struct mpc52xx_psc __iomem *psc = mps->psc;
+ u32 sicr;
+ u16 ccr;
+
+ 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);
+
+ /* Set clock frequency and bits per word
+ * Because psc->ccr is defined as 16bit register instead of 32bit
+ * just set the lower byte of BitClkDiv
+ */
+ ccr = in_be16((u16 __iomem *)&psc->ccr);
+ ccr &= 0xFF00;
+ if (cs->speed_hz)
+ ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
+ else /* by default SPI Clk 1MHz */
+ ccr |= (MCLK / 1000000 - 1) & 0xFF;
+ out_be16((u16 __iomem *)&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 mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
+{
+ struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+
+ if (mps->cs_control)
+ mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
+}
+
+#define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
+/* wake up when 80% fifo full */
+#define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
+
+static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+ struct mpc52xx_psc __iomem *psc = mps->psc;
+ struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
+ unsigned rb = 0; /* number of bytes receieved */
+ unsigned sb = 0; /* number of bytes sent */
+ unsigned char *rx_buf = (unsigned char *)t->rx_buf;
+ unsigned char *tx_buf = (unsigned char *)t->tx_buf;
+ unsigned rfalarm;
+ unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
+ unsigned recv_at_once;
+ int last_block = 0;
+
+ if (!t->tx_buf && !t->rx_buf && t->len)
+ return -EINVAL;
+
+ /* enable transmiter/receiver */
+ out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
+ while (rb < t->len) {
+ if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
+ rfalarm = MPC52xx_PSC_RFALARM;
+ last_block = 0;
+ } else {
+ send_at_once = t->len - sb;
+ rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
+ last_block = 1;
+ }
+
+ dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
+ for (; send_at_once; sb++, send_at_once--) {
+ /* set EOF flag before the last word is sent */
+ if (send_at_once == 1 && last_block)
+ out_8(&psc->ircr2, 0x01);
+
+ if (tx_buf)
+ out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
+ else
+ out_8(&psc->mpc52xx_psc_buffer_8, 0);
+ }
+
+
+ /* enable interrupts and wait for wake up
+ * if just one byte is expected the Rx FIFO genererates no
+ * FFULL interrupt, so activate the RxRDY interrupt
+ */
+ out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
+ if (t->len - rb == 1) {
+ out_8(&psc->mode, 0);
+ } else {
+ out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
+ out_be16(&fifo->rfalarm, rfalarm);
+ }
+ out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
+ wait_for_completion(&mps->done);
+ recv_at_once = in_be16(&fifo->rfnum);
+ dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
+
+ send_at_once = recv_at_once;
+ if (rx_buf) {
+ for (; recv_at_once; rb++, recv_at_once--)
+ rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
+ } else {
+ for (; recv_at_once; rb++, recv_at_once--)
+ in_8(&psc->mpc52xx_psc_buffer_8);
+ }
+ }
+ /* disable transmiter/receiver */
+ out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+
+ return 0;
+}
+
+static void mpc52xx_psc_spi_work(struct work_struct *work)
+{
+ struct mpc52xx_psc_spi *mps =
+ container_of(work, struct mpc52xx_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 = mpc52xx_psc_spi_transfer_setup(spi, t);
+ if (status < 0)
+ break;
+ }
+
+ if (cs_change)
+ mpc52xx_psc_spi_activate_cs(spi);
+ cs_change = t->cs_change;
+
+ status = mpc52xx_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)
+ mpc52xx_psc_spi_deactivate_cs(spi);
+ }
+
+ m->status = status;
+ if (m->complete)
+ m->complete(m->context);
+
+ if (status || !cs_change)
+ mpc52xx_psc_spi_deactivate_cs(spi);
+
+ mpc52xx_psc_spi_transfer_setup(spi, NULL);
+
+ spin_lock_irq(&mps->lock);
+ }
+ mps->busy = 0;
+ spin_unlock_irq(&mps->lock);
+}
+
+static int mpc52xx_psc_spi_setup(struct spi_device *spi)
+{
+ struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
+ struct mpc52xx_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)
+ mpc52xx_psc_spi_deactivate_cs(spi);
+ spin_unlock_irqrestore(&mps->lock, flags);
+
+ return 0;
+}
+
+static int mpc52xx_psc_spi_transfer(struct spi_device *spi,
+ struct spi_message *m)
+{
+ struct mpc52xx_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 mpc52xx_psc_spi_cleanup(struct spi_device *spi)
+{
+ kfree(spi->controller_state);
+}
+
+static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
+{
+ struct mpc52xx_psc __iomem *psc = mps->psc;
+ struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
+ u32 mclken_div;
+ int ret;
+
+ /* default sysclk is 512MHz */
+ mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
+ ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
+ if (ret)
+ return ret;
+
+ /* 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 interrupts, interrupts are based on alarm level */
+ out_be16(&psc->mpc52xx_psc_imr, 0);
+ out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
+ out_8(&fifo->rfcntl, 0);
+ out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
+
+ /* Configure 8bit codec mode as a SPI master and use EOF flags */
+ /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
+ out_be32(&psc->sicr, 0x0180C800);
+ out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */
+
+ /* Set 2ms DTL delay */
+ out_8(&psc->ctur, 0x00);
+ out_8(&psc->ctlr, 0x84);
+
+ mps->bits_per_word = 8;
+
+ return 0;
+}
+
+static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
+{
+ struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
+ struct mpc52xx_psc __iomem *psc = mps->psc;
+
+ /* disable interrupt and wake up the work queue */
+ if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
+ out_be16(&psc->mpc52xx_psc_imr, 0);
+ complete(&mps->done);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+/* bus_num is used only for the case dev->platform_data == NULL */
+static int mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
+ u32 size, unsigned int irq, s16 bus_num)
+{
+ struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
+ struct mpc52xx_psc_spi *mps;
+ struct spi_master *master;
+ int ret;
+
+ master = spi_alloc_master(dev, sizeof *mps);
+ if (master == NULL)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, master);
+ mps = spi_master_get_devdata(master);
+
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+
+ mps->irq = irq;
+ if (pdata == NULL) {
+ dev_warn(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 = mpc52xx_psc_spi_setup;
+ master->transfer = mpc52xx_psc_spi_transfer;
+ master->cleanup = mpc52xx_psc_spi_cleanup;
+ master->dev.of_node = dev->of_node;
+
+ mps->psc = ioremap(regaddr, size);
+ if (!mps->psc) {
+ dev_err(dev, "could not ioremap I/O port range\n");
+ ret = -EFAULT;
+ goto free_master;
+ }
+ /* On the 5200, fifo regs are immediately ajacent to the psc regs */
+ mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
+
+ ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
+ mps);
+ if (ret)
+ goto free_master;
+
+ ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
+ if (ret < 0) {
+ dev_err(dev, "can't configure PSC! Is it capable of SPI?\n");
+ goto free_irq;
+ }
+
+ spin_lock_init(&mps->lock);
+ init_completion(&mps->done);
+ INIT_WORK(&mps->work, mpc52xx_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 mpc52xx_psc_spi_of_probe(struct platform_device *op)
+{
+ const u32 *regaddr_p;
+ u64 regaddr64, size64;
+ s16 id = -1;
+
+ regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL);
+ if (!regaddr_p) {
+ dev_err(&op->dev, "Invalid PSC address\n");
+ return -EINVAL;
+ }
+ regaddr64 = of_translate_address(op->dev.of_node, regaddr_p);
+
+ /* get PSC id (1..6, used by port_config) */
+ if (op->dev.platform_data == NULL) {
+ const u32 *psc_nump;
+
+ psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL);
+ if (!psc_nump || *psc_nump > 5) {
+ dev_err(&op->dev, "Invalid cell-index property\n");
+ return -EINVAL;
+ }
+ id = *psc_nump + 1;
+ }
+
+ return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
+ irq_of_parse_and_map(op->dev.of_node, 0), id);
+}
+
+static int mpc52xx_psc_spi_of_remove(struct platform_device *op)
+{
+ struct spi_master *master = spi_master_get(platform_get_drvdata(op));
+ struct mpc52xx_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);
+ spi_master_put(master);
+
+ return 0;
+}
+
+static const struct of_device_id mpc52xx_psc_spi_of_match[] = {
+ { .compatible = "fsl,mpc5200-psc-spi", },
+ { .compatible = "mpc5200-psc-spi", }, /* old */
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
+
+static struct platform_driver mpc52xx_psc_spi_of_driver = {
+ .probe = mpc52xx_psc_spi_of_probe,
+ .remove = mpc52xx_psc_spi_of_remove,
+ .driver = {
+ .name = "mpc52xx-psc-spi",
+ .of_match_table = mpc52xx_psc_spi_of_match,
+ },
+};
+module_platform_driver(mpc52xx_psc_spi_of_driver);
+
+MODULE_AUTHOR("Dragos Carp");
+MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
+MODULE_LICENSE("GPL");
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