Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 437 insertions, 0 deletions

diff --git a/drivers/spi/spi-txx9.c b/drivers/spi/spi-txx9.c
new file mode 100644
index 000000000..51759d3fd
--- /dev/null
+++ b/drivers/spi/spi-txx9.c
@@ -0,0 +1,437 @@
+/*
+ * TXx9 SPI controller driver.
+ *
+ * Based on linux/arch/mips/tx4938/toshiba_rbtx4938/spi_txx9.c
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ *
+ * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
+ *
+ * Convert to generic SPI framework - Atsushi Nemoto (anemo@mba.ocn.ne.jp)
+ */
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+
+
+#define SPI_FIFO_SIZE 4
+#define SPI_MAX_DIVIDER 0xff	/* Max. value for SPCR1.SER */
+#define SPI_MIN_DIVIDER 1	/* Min. value for SPCR1.SER */
+
+#define TXx9_SPMCR		0x00
+#define TXx9_SPCR0		0x04
+#define TXx9_SPCR1		0x08
+#define TXx9_SPFS		0x0c
+#define TXx9_SPSR		0x14
+#define TXx9_SPDR		0x18
+
+/* SPMCR : SPI Master Control */
+#define TXx9_SPMCR_OPMODE	0xc0
+#define TXx9_SPMCR_CONFIG	0x40
+#define TXx9_SPMCR_ACTIVE	0x80
+#define TXx9_SPMCR_SPSTP	0x02
+#define TXx9_SPMCR_BCLR		0x01
+
+/* SPCR0 : SPI Control 0 */
+#define TXx9_SPCR0_TXIFL_MASK	0xc000
+#define TXx9_SPCR0_RXIFL_MASK	0x3000
+#define TXx9_SPCR0_SIDIE	0x0800
+#define TXx9_SPCR0_SOEIE	0x0400
+#define TXx9_SPCR0_RBSIE	0x0200
+#define TXx9_SPCR0_TBSIE	0x0100
+#define TXx9_SPCR0_IFSPSE	0x0010
+#define TXx9_SPCR0_SBOS		0x0004
+#define TXx9_SPCR0_SPHA		0x0002
+#define TXx9_SPCR0_SPOL		0x0001
+
+/* SPSR : SPI Status */
+#define TXx9_SPSR_TBSI		0x8000
+#define TXx9_SPSR_RBSI		0x4000
+#define TXx9_SPSR_TBS_MASK	0x3800
+#define TXx9_SPSR_RBS_MASK	0x0700
+#define TXx9_SPSR_SPOE		0x0080
+#define TXx9_SPSR_IFSD		0x0008
+#define TXx9_SPSR_SIDLE		0x0004
+#define TXx9_SPSR_STRDY		0x0002
+#define TXx9_SPSR_SRRDY		0x0001
+
+
+struct txx9spi {
+	struct work_struct work;
+	spinlock_t lock;	/* protect 'queue' */
+	struct list_head queue;
+	wait_queue_head_t waitq;
+	void __iomem *membase;
+	int baseclk;
+	struct clk *clk;
+	int last_chipselect;
+	int last_chipselect_val;
+};
+
+static u32 txx9spi_rd(struct txx9spi *c, int reg)
+{
+	return __raw_readl(c->membase + reg);
+}
+static void txx9spi_wr(struct txx9spi *c, u32 val, int reg)
+{
+	__raw_writel(val, c->membase + reg);
+}
+
+static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
+		int on, unsigned int cs_delay)
+{
+	int val = (spi->mode & SPI_CS_HIGH) ? on : !on;
+
+	if (on) {
+		/* deselect the chip with cs_change hint in last transfer */
+		if (c->last_chipselect >= 0)
+			gpio_set_value(c->last_chipselect,
+					!c->last_chipselect_val);
+		c->last_chipselect = spi->chip_select;
+		c->last_chipselect_val = val;
+	} else {
+		c->last_chipselect = -1;
+		ndelay(cs_delay);	/* CS Hold Time */
+	}
+	gpio_set_value(spi->chip_select, val);
+	ndelay(cs_delay);	/* CS Setup Time / CS Recovery Time */
+}
+
+static int txx9spi_setup(struct spi_device *spi)
+{
+	struct txx9spi *c = spi_master_get_devdata(spi->master);
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	if (gpio_direction_output(spi->chip_select,
+			!(spi->mode & SPI_CS_HIGH))) {
+		dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
+		return -EINVAL;
+	}
+
+	/* deselect chip */
+	spin_lock(&c->lock);
+	txx9spi_cs_func(spi, c, 0, (NSEC_PER_SEC / 2) / spi->max_speed_hz);
+	spin_unlock(&c->lock);
+
+	return 0;
+}
+
+static irqreturn_t txx9spi_interrupt(int irq, void *dev_id)
+{
+	struct txx9spi *c = dev_id;
+
+	/* disable rx intr */
+	txx9spi_wr(c, txx9spi_rd(c, TXx9_SPCR0) & ~TXx9_SPCR0_RBSIE,
+			TXx9_SPCR0);
+	wake_up(&c->waitq);
+	return IRQ_HANDLED;
+}
+
+static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m)
+{
+	struct spi_device *spi = m->spi;
+	struct spi_transfer *t;
+	unsigned int cs_delay;
+	unsigned int cs_change = 1;
+	int status = 0;
+	u32 mcr;
+	u32 prev_speed_hz = 0;
+	u8 prev_bits_per_word = 0;
+
+	/* CS setup/hold/recovery time in nsec */
+	cs_delay = 100 + (NSEC_PER_SEC / 2) / spi->max_speed_hz;
+
+	mcr = txx9spi_rd(c, TXx9_SPMCR);
+	if (unlikely((mcr & TXx9_SPMCR_OPMODE) == TXx9_SPMCR_ACTIVE)) {
+		dev_err(&spi->dev, "Bad mode.\n");
+		status = -EIO;
+		goto exit;
+	}
+	mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
+
+	/* enter config mode */
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+	txx9spi_wr(c, TXx9_SPCR0_SBOS
+			| ((spi->mode & SPI_CPOL) ? TXx9_SPCR0_SPOL : 0)
+			| ((spi->mode & SPI_CPHA) ? TXx9_SPCR0_SPHA : 0)
+			| 0x08,
+			TXx9_SPCR0);
+
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		const void *txbuf = t->tx_buf;
+		void *rxbuf = t->rx_buf;
+		u32 data;
+		unsigned int len = t->len;
+		unsigned int wsize;
+		u32 speed_hz = t->speed_hz;
+		u8 bits_per_word = t->bits_per_word;
+
+		wsize = bits_per_word >> 3; /* in bytes */
+
+		if (prev_speed_hz != speed_hz
+				|| prev_bits_per_word != bits_per_word) {
+			int n = DIV_ROUND_UP(c->baseclk, speed_hz) - 1;
+
+			n = clamp(n, SPI_MIN_DIVIDER, SPI_MAX_DIVIDER);
+			/* enter config mode */
+			txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR,
+					TXx9_SPMCR);
+			txx9spi_wr(c, (n << 8) | bits_per_word, TXx9_SPCR1);
+			/* enter active mode */
+			txx9spi_wr(c, mcr | TXx9_SPMCR_ACTIVE, TXx9_SPMCR);
+
+			prev_speed_hz = speed_hz;
+			prev_bits_per_word = bits_per_word;
+		}
+
+		if (cs_change)
+			txx9spi_cs_func(spi, c, 1, cs_delay);
+		cs_change = t->cs_change;
+		while (len) {
+			unsigned int count = SPI_FIFO_SIZE;
+			int i;
+			u32 cr0;
+
+			if (len < count * wsize)
+				count = len / wsize;
+			/* now tx must be idle... */
+			while (!(txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_SIDLE))
+				cpu_relax();
+			cr0 = txx9spi_rd(c, TXx9_SPCR0);
+			cr0 &= ~TXx9_SPCR0_RXIFL_MASK;
+			cr0 |= (count - 1) << 12;
+			/* enable rx intr */
+			cr0 |= TXx9_SPCR0_RBSIE;
+			txx9spi_wr(c, cr0, TXx9_SPCR0);
+			/* send */
+			for (i = 0; i < count; i++) {
+				if (txbuf) {
+					data = (wsize == 1)
+						? *(const u8 *)txbuf
+						: *(const u16 *)txbuf;
+					txx9spi_wr(c, data, TXx9_SPDR);
+					txbuf += wsize;
+				} else
+					txx9spi_wr(c, 0, TXx9_SPDR);
+			}
+			/* wait all rx data */
+			wait_event(c->waitq,
+				txx9spi_rd(c, TXx9_SPSR) & TXx9_SPSR_RBSI);
+			/* receive */
+			for (i = 0; i < count; i++) {
+				data = txx9spi_rd(c, TXx9_SPDR);
+				if (rxbuf) {
+					if (wsize == 1)
+						*(u8 *)rxbuf = data;
+					else
+						*(u16 *)rxbuf = data;
+					rxbuf += wsize;
+				}
+			}
+			len -= count * wsize;
+		}
+		m->actual_length += t->len;
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		if (!cs_change)
+			continue;
+		if (t->transfer_list.next == &m->transfers)
+			break;
+		/* sometimes a short mid-message deselect of the chip
+		 * may be needed to terminate a mode or command
+		 */
+		txx9spi_cs_func(spi, c, 0, cs_delay);
+	}
+
+exit:
+	m->status = status;
+	if (m->complete)
+		m->complete(m->context);
+
+	/* normally deactivate chipselect ... unless no error and
+	 * cs_change has hinted that the next message will probably
+	 * be for this chip too.
+	 */
+	if (!(status == 0 && cs_change))
+		txx9spi_cs_func(spi, c, 0, cs_delay);
+
+	/* enter config mode */
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+}
+
+static void txx9spi_work(struct work_struct *work)
+{
+	struct txx9spi *c = container_of(work, struct txx9spi, work);
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->lock, flags);
+	while (!list_empty(&c->queue)) {
+		struct spi_message *m;
+
+		m = container_of(c->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&c->lock, flags);
+
+		txx9spi_work_one(c, m);
+
+		spin_lock_irqsave(&c->lock, flags);
+	}
+	spin_unlock_irqrestore(&c->lock, flags);
+}
+
+static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct spi_master *master = spi->master;
+	struct txx9spi *c = spi_master_get_devdata(master);
+	struct spi_transfer *t;
+	unsigned long flags;
+
+	m->actual_length = 0;
+
+	/* check each transfer's parameters */
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		if (!t->tx_buf && !t->rx_buf && t->len)
+			return -EINVAL;
+	}
+
+	spin_lock_irqsave(&c->lock, flags);
+	list_add_tail(&m->queue, &c->queue);
+	schedule_work(&c->work);
+	spin_unlock_irqrestore(&c->lock, flags);
+
+	return 0;
+}
+
+static int txx9spi_probe(struct platform_device *dev)
+{
+	struct spi_master *master;
+	struct txx9spi *c;
+	struct resource *res;
+	int ret = -ENODEV;
+	u32 mcr;
+	int irq;
+
+	master = spi_alloc_master(&dev->dev, sizeof(*c));
+	if (!master)
+		return ret;
+	c = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	INIT_WORK(&c->work, txx9spi_work);
+	spin_lock_init(&c->lock);
+	INIT_LIST_HEAD(&c->queue);
+	init_waitqueue_head(&c->waitq);
+
+	c->clk = devm_clk_get(&dev->dev, "spi-baseclk");
+	if (IS_ERR(c->clk)) {
+		ret = PTR_ERR(c->clk);
+		c->clk = NULL;
+		goto exit;
+	}
+	ret = clk_prepare_enable(c->clk);
+	if (ret) {
+		c->clk = NULL;
+		goto exit;
+	}
+	c->baseclk = clk_get_rate(c->clk);
+	master->min_speed_hz = DIV_ROUND_UP(c->baseclk, SPI_MAX_DIVIDER + 1);
+	master->max_speed_hz = c->baseclk / (SPI_MIN_DIVIDER + 1);
+
+	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	c->membase = devm_ioremap_resource(&dev->dev, res);
+	if (IS_ERR(c->membase))
+		goto exit_busy;
+
+	/* enter config mode */
+	mcr = txx9spi_rd(c, TXx9_SPMCR);
+	mcr &= ~(TXx9_SPMCR_OPMODE | TXx9_SPMCR_SPSTP | TXx9_SPMCR_BCLR);
+	txx9spi_wr(c, mcr | TXx9_SPMCR_CONFIG | TXx9_SPMCR_BCLR, TXx9_SPMCR);
+
+	irq = platform_get_irq(dev, 0);
+	if (irq < 0)
+		goto exit_busy;
+	ret = devm_request_irq(&dev->dev, irq, txx9spi_interrupt, 0,
+			       "spi_txx9", c);
+	if (ret)
+		goto exit;
+
+	c->last_chipselect = -1;
+
+	dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
+		 (unsigned long long)res->start, irq,
+		 (c->baseclk + 500000) / 1000000);
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
+
+	master->bus_num = dev->id;
+	master->setup = txx9spi_setup;
+	master->transfer = txx9spi_transfer;
+	master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */
+	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+
+	ret = devm_spi_register_master(&dev->dev, master);
+	if (ret)
+		goto exit;
+	return 0;
+exit_busy:
+	ret = -EBUSY;
+exit:
+	clk_disable_unprepare(c->clk);
+	spi_master_put(master);
+	return ret;
+}
+
+static int txx9spi_remove(struct platform_device *dev)
+{
+	struct spi_master *master = platform_get_drvdata(dev);
+	struct txx9spi *c = spi_master_get_devdata(master);
+
+	flush_work(&c->work);
+	clk_disable_unprepare(c->clk);
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:spi_txx9");
+
+static struct platform_driver txx9spi_driver = {
+	.probe = txx9spi_probe,
+	.remove = txx9spi_remove,
+	.driver = {
+		.name = "spi_txx9",
+	},
+};
+
+static int __init txx9spi_init(void)
+{
+	return platform_driver_register(&txx9spi_driver);
+}
+subsys_initcall(txx9spi_init);
+
+static void __exit txx9spi_exit(void)
+{
+	platform_driver_unregister(&txx9spi_driver);
+}
+module_exit(txx9spi_exit);
+
+MODULE_DESCRIPTION("TXx9 SPI Driver");
+MODULE_LICENSE("GPL");