diff options
Diffstat (limited to 'drivers/spi/mpc512x_psc_spi.c')
| -rw-r--r-- | drivers/spi/mpc512x_psc_spi.c | 576 | 
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"); | 
