drivers/spi/spi-mpc52xx-psc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * MPC52xx PSC in SPI mode driver.
  *
  * Maintainer: Dragos Carp
  *
  * Copyright (C) 2006 TOPTICA Photonics AG.
  */

 #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 <linux/of_irq.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 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;

 			spi_transfer_delay_exec(t);

 			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);
 	schedule_work(&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);

 	ret = spi_register_master(master);
 	if (ret < 0)
 		goto free_irq;

 	return ret;

 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_work(&mps->work);
 	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");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* MPC52xx PSC in SPI mode driver.
	*
	* Maintainer: Dragos Carp
	*
	* Copyright (C) 2006 TOPTICA Photonics AG.
	*/

	#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 <linux/of_irq.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 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;

	spi_transfer_delay_exec(t);

	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);
	schedule_work(&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);

	ret = spi_register_master(master);
	if (ret < 0)
	goto free_irq;

	return ret;

	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_work(&mps->work);
	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");