Fixed MTP to work with TWRP

drivers/spi/spi-bcm63xx.c

@@ -0,0 +1,485 @@
+/*
+ * Broadcom BCM63xx SPI controller support
+ *
+ * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
+
+#include <bcm63xx_dev_spi.h>
+
+#define BCM63XX_SPI_MAX_PREPEND		15
+
+struct bcm63xx_spi {
+	struct completion	done;
+
+	void __iomem		*regs;
+	int			irq;
+
+	/* Platform data */
+	unsigned		fifo_size;
+	unsigned int		msg_type_shift;
+	unsigned int		msg_ctl_width;
+
+	/* data iomem */
+	u8 __iomem		*tx_io;
+	const u8 __iomem	*rx_io;
+
+	struct clk		*clk;
+	struct platform_device	*pdev;
+};
+
+static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
+				unsigned int offset)
+{
+	return bcm_readb(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
+				unsigned int offset)
+{
+	return bcm_readw(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
+				  u8 value, unsigned int offset)
+{
+	bcm_writeb(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
+				  u16 value, unsigned int offset)
+{
+	bcm_writew(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
+	{ 20000000, SPI_CLK_20MHZ },
+	{ 12500000, SPI_CLK_12_50MHZ },
+	{  6250000, SPI_CLK_6_250MHZ },
+	{  3125000, SPI_CLK_3_125MHZ },
+	{  1563000, SPI_CLK_1_563MHZ },
+	{   781000, SPI_CLK_0_781MHZ },
+	{   391000, SPI_CLK_0_391MHZ }
+};
+
+static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
+				      struct spi_transfer *t)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+	u8 clk_cfg, reg;
+	int i;
+
+	/* Find the closest clock configuration */
+	for (i = 0; i < SPI_CLK_MASK; i++) {
+		if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
+			clk_cfg = bcm63xx_spi_freq_table[i][1];
+			break;
+		}
+	}
+
+	/* No matching configuration found, default to lowest */
+	if (i == SPI_CLK_MASK)
+		clk_cfg = SPI_CLK_0_391MHZ;
+
+	/* clear existing clock configuration bits of the register */
+	reg = bcm_spi_readb(bs, SPI_CLK_CFG);
+	reg &= ~SPI_CLK_MASK;
+	reg |= clk_cfg;
+
+	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
+	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
+		clk_cfg, t->speed_hz);
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+
+static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
+				unsigned int num_transfers)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+	u16 msg_ctl;
+	u16 cmd;
+	u8 rx_tail;
+	unsigned int i, timeout = 0, prepend_len = 0, len = 0;
+	struct spi_transfer *t = first;
+	bool do_rx = false;
+	bool do_tx = false;
+
+	/* Disable the CMD_DONE interrupt */
+	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+		t->tx_buf, t->rx_buf, t->len);
+
+	if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
+		prepend_len = t->len;
+
+	/* prepare the buffer */
+	for (i = 0; i < num_transfers; i++) {
+		if (t->tx_buf) {
+			do_tx = true;
+			memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
+
+			/* don't prepend more than one tx */
+			if (t != first)
+				prepend_len = 0;
+		}
+
+		if (t->rx_buf) {
+			do_rx = true;
+			/* prepend is half-duplex write only */
+			if (t == first)
+				prepend_len = 0;
+		}
+
+		len += t->len;
+
+		t = list_entry(t->transfer_list.next, struct spi_transfer,
+			       transfer_list);
+	}
+
+	reinit_completion(&bs->done);
+
+	/* Fill in the Message control register */
+	msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
+
+	if (do_rx && do_tx && prepend_len == 0)
+		msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
+	else if (do_rx)
+		msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
+	else if (do_tx)
+		msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
+
+	switch (bs->msg_ctl_width) {
+	case 8:
+		bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
+		break;
+	case 16:
+		bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
+		break;
+	}
+
+	/* Issue the transfer */
+	cmd = SPI_CMD_START_IMMEDIATE;
+	cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
+	bcm_spi_writew(bs, cmd, SPI_CMD);
+
+	/* Enable the CMD_DONE interrupt */
+	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+
+	timeout = wait_for_completion_timeout(&bs->done, HZ);
+	if (!timeout)
+		return -ETIMEDOUT;
+
+	if (!do_rx)
+		return 0;
+
+	len = 0;
+	t = first;
+	/* Read out all the data */
+	for (i = 0; i < num_transfers; i++) {
+		if (t->rx_buf)
+			memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
+
+		if (t != first || prepend_len == 0)
+			len += t->len;
+
+		t = list_entry(t->transfer_list.next, struct spi_transfer,
+			       transfer_list);
+	}
+
+	return 0;
+}
+
+static int bcm63xx_spi_transfer_one(struct spi_master *master,
+					struct spi_message *m)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+	struct spi_transfer *t, *first = NULL;
+	struct spi_device *spi = m->spi;
+	int status = 0;
+	unsigned int n_transfers = 0, total_len = 0;
+	bool can_use_prepend = false;
+
+	/*
+	 * This SPI controller does not support keeping CS active after a
+	 * transfer.
+	 * Work around this by merging as many transfers we can into one big
+	 * full-duplex transfers.
+	 */
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		if (!first)
+			first = t;
+
+		n_transfers++;
+		total_len += t->len;
+
+		if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
+		    first->len <= BCM63XX_SPI_MAX_PREPEND)
+			can_use_prepend = true;
+		else if (can_use_prepend && t->tx_buf)
+			can_use_prepend = false;
+
+		/* we can only transfer one fifo worth of data */
+		if ((can_use_prepend &&
+		     total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
+		    (!can_use_prepend && total_len > bs->fifo_size)) {
+			dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
+				total_len, bs->fifo_size);
+			status = -EINVAL;
+			goto exit;
+		}
+
+		/* all combined transfers have to have the same speed */
+		if (t->speed_hz != first->speed_hz) {
+			dev_err(&spi->dev, "unable to change speed between transfers\n");
+			status = -EINVAL;
+			goto exit;
+		}
+
+		/* CS will be deasserted directly after transfer */
+		if (t->delay_usecs) {
+			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
+			status = -EINVAL;
+			goto exit;
+		}
+
+		if (t->cs_change ||
+		    list_is_last(&t->transfer_list, &m->transfers)) {
+			/* configure adapter for a new transfer */
+			bcm63xx_spi_setup_transfer(spi, first);
+
+			/* send the data */
+			status = bcm63xx_txrx_bufs(spi, first, n_transfers);
+			if (status)
+				goto exit;
+
+			m->actual_length += total_len;
+
+			first = NULL;
+			n_transfers = 0;
+			total_len = 0;
+			can_use_prepend = false;
+		}
+	}
+exit:
+	m->status = status;
+	spi_finalize_current_message(master);
+
+	return 0;
+}
+
+/* This driver supports single master mode only. Hence
+ * CMD_DONE is the only interrupt we care about
+ */
+static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
+{
+	struct spi_master *master = (struct spi_master *)dev_id;
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+	u8 intr;
+
+	/* Read interupts and clear them immediately */
+	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
+	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+	/* A transfer completed */
+	if (intr & SPI_INTR_CMD_DONE)
+		complete(&bs->done);
+
+	return IRQ_HANDLED;
+}
+
+
+static int bcm63xx_spi_probe(struct platform_device *pdev)
+{
+	struct resource *r;
+	struct device *dev = &pdev->dev;
+	struct bcm63xx_spi_pdata *pdata = dev_get_platdata(&pdev->dev);
+	int irq;
+	struct spi_master *master;
+	struct clk *clk;
+	struct bcm63xx_spi *bs;
+	int ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no irq\n");
+		return -ENXIO;
+	}
+
+	clk = devm_clk_get(dev, "spi");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "no clock for device\n");
+		return PTR_ERR(clk);
+	}
+
+	master = spi_alloc_master(dev, sizeof(*bs));
+	if (!master) {
+		dev_err(dev, "out of memory\n");
+		return -ENOMEM;
+	}
+
+	bs = spi_master_get_devdata(master);
+	init_completion(&bs->done);
+
+	platform_set_drvdata(pdev, master);
+	bs->pdev = pdev;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bs->regs = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(bs->regs)) {
+		ret = PTR_ERR(bs->regs);
+		goto out_err;
+	}
+
+	bs->irq = irq;
+	bs->clk = clk;
+	bs->fifo_size = pdata->fifo_size;
+
+	ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
+							pdev->name, master);
+	if (ret) {
+		dev_err(dev, "unable to request irq\n");
+		goto out_err;
+	}
+
+	master->bus_num = pdata->bus_num;
+	master->num_chipselect = pdata->num_chipselect;
+	master->transfer_one_message = bcm63xx_spi_transfer_one;
+	master->mode_bits = MODEBITS;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	master->auto_runtime_pm = true;
+	bs->msg_type_shift = pdata->msg_type_shift;
+	bs->msg_ctl_width = pdata->msg_ctl_width;
+	bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));
+	bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA));
+
+	switch (bs->msg_ctl_width) {
+	case 8:
+	case 16:
+		break;
+	default:
+		dev_err(dev, "unsupported MSG_CTL width: %d\n",
+			 bs->msg_ctl_width);
+		goto out_err;
+	}
+
+	/* Initialize hardware */
+	ret = clk_prepare_enable(bs->clk);
+	if (ret)
+		goto out_err;
+
+	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+
+	/* register and we are done */
+	ret = devm_spi_register_master(dev, master);
+	if (ret) {
+		dev_err(dev, "spi register failed\n");
+		goto out_clk_disable;
+	}
+
+	dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d)\n",
+		 r->start, irq, bs->fifo_size);
+
+	return 0;
+
+out_clk_disable:
+	clk_disable_unprepare(clk);
+out_err:
+	spi_master_put(master);
+	return ret;
+}
+
+static int bcm63xx_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+	/* reset spi block */
+	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+	/* HW shutdown */
+	clk_disable_unprepare(bs->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bcm63xx_spi_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+	spi_master_suspend(master);
+
+	clk_disable_unprepare(bs->clk);
+
+	return 0;
+}
+
+static int bcm63xx_spi_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+	int ret;
+
+	ret = clk_prepare_enable(bs->clk);
+	if (ret)
+		return ret;
+
+	spi_master_resume(master);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
+};
+
+static struct platform_driver bcm63xx_spi_driver = {
+	.driver = {
+		.name	= "bcm63xx-spi",
+		.owner	= THIS_MODULE,
+		.pm	= &bcm63xx_spi_pm_ops,
+	},
+	.probe		= bcm63xx_spi_probe,
+	.remove		= bcm63xx_spi_remove,
+};
+
+module_platform_driver(bcm63xx_spi_driver);
+
+MODULE_ALIAS("platform:bcm63xx_spi");
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
+MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
+MODULE_LICENSE("GPL");