Fixed MTP to work with TWRP

drivers/spi/spi-mpc512x-psc.c

@@ -0,0 +1,611 @@
+/*
+ * 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/errno.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.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 <linux/gpio.h>
+#include <asm/mpc52xx_psc.h>
+
+struct mpc512x_psc_spi {
+	void (*cs_control)(struct spi_device *spi, bool on);
+
+	/* driver internal data */
+	struct mpc52xx_psc __iomem *psc;
+	struct mpc512x_psc_fifo __iomem *fifo;
+	unsigned int irq;
+	u8 bits_per_word;
+	struct clk *clk_mclk;
+	struct clk *clk_ipg;
+	u32 mclk_rate;
+
+	struct completion txisrdone;
+};
+
+/* 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;
+	int speed;
+	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;
+	speed = cs->speed_hz;
+	if (!speed)
+		speed = 1000000;	/* default 1MHz */
+	bclkdiv = (mps->mclk_rate / speed) - 1;
+
+	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 && gpio_is_valid(spi->cs_gpio))
+		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 && gpio_is_valid(spi->cs_gpio))
+		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 mpc512x_psc_fifo __iomem *fifo = mps->fifo;
+	size_t tx_len = t->len;
+	size_t rx_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;
+
+	while (rx_len || tx_len) {
+		size_t txcount;
+		u8 data;
+		size_t fifosz;
+		size_t rxcount;
+		int rxtries;
+
+		/*
+		 * send the TX bytes in as large a chunk as possible
+		 * but neither exceed the TX nor the RX FIFOs
+		 */
+		fifosz = MPC512x_PSC_FIFO_SZ(in_be32(&fifo->txsz));
+		txcount = min(fifosz, tx_len);
+		fifosz = MPC512x_PSC_FIFO_SZ(in_be32(&fifo->rxsz));
+		fifosz -= in_be32(&fifo->rxcnt) + 1;
+		txcount = min(fifosz, txcount);
+		if (txcount) {
+
+			/* fill the TX FIFO */
+			while (txcount-- > 0) {
+				data = tx_buf ? *tx_buf++ : 0;
+				if (tx_len == EOFBYTE && t->cs_change)
+					setbits32(&fifo->txcmd,
+						  MPC512x_PSC_FIFO_EOF);
+				out_8(&fifo->txdata_8, data);
+				tx_len--;
+			}
+
+			/* have the ISR trigger when the TX FIFO is empty */
+			reinit_completion(&mps->txisrdone);
+			out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY);
+			out_be32(&fifo->tximr, MPC512x_PSC_FIFO_EMPTY);
+			wait_for_completion(&mps->txisrdone);
+		}
+
+		/*
+		 * consume as much RX data as the FIFO holds, while we
+		 * iterate over the transfer's TX data length
+		 *
+		 * only insist in draining all the remaining RX bytes
+		 * when the TX bytes were exhausted (that's at the very
+		 * end of this transfer, not when still iterating over
+		 * the transfer's chunks)
+		 */
+		rxtries = 50;
+		do {
+
+			/*
+			 * grab whatever was in the FIFO when we started
+			 * looking, don't bother fetching what was added to
+			 * the FIFO while we read from it -- we'll return
+			 * here eventually and prefer sending out remaining
+			 * TX data
+			 */
+			fifosz = in_be32(&fifo->rxcnt);
+			rxcount = min(fifosz, rx_len);
+			while (rxcount-- > 0) {
+				data = in_8(&fifo->rxdata_8);
+				if (rx_buf)
+					*rx_buf++ = data;
+				rx_len--;
+			}
+
+			/*
+			 * come back later if there still is TX data to send,
+			 * bail out of the RX drain loop if all of the TX data
+			 * was sent and all of the RX data was received (i.e.
+			 * when the transmission has completed)
+			 */
+			if (tx_len)
+				break;
+			if (!rx_len)
+				break;
+
+			/*
+			 * TX data transmission has completed while RX data
+			 * is still pending -- that's a transient situation
+			 * which depends on wire speed and specific
+			 * hardware implementation details (buffering) yet
+			 * should resolve very quickly
+			 *
+			 * just yield for a moment to not hog the CPU for
+			 * too long when running SPI at low speed
+			 *
+			 * the timeout range is rather arbitrary and tries
+			 * to balance throughput against system load; the
+			 * chosen values result in a minimal timeout of 50
+			 * times 10us and thus work at speeds as low as
+			 * some 20kbps, while the maximum timeout at the
+			 * transfer's end could be 5ms _if_ nothing else
+			 * ticks in the system _and_ RX data still wasn't
+			 * received, which only occurs in situations that
+			 * are exceptional; removing the unpredictability
+			 * of the timeout either decreases throughput
+			 * (longer timeouts), or puts more load on the
+			 * system (fixed short timeouts) or requires the
+			 * use of a timeout API instead of a counter and an
+			 * unknown inner delay
+			 */
+			usleep_range(10, 100);
+
+		} while (--rxtries > 0);
+		if (!tx_len && rx_len && !rxtries) {
+			/*
+			 * not enough RX bytes even after several retries
+			 * and the resulting rather long timeout?
+			 */
+			rxcount = in_be32(&fifo->rxcnt);
+			dev_warn(&spi->dev,
+				 "short xfer, missing %zd RX bytes, FIFO level %zd\n",
+				 rx_len, rxcount);
+		}
+
+		/*
+		 * drain and drop RX data which "should not be there" in
+		 * the first place, for undisturbed transmission this turns
+		 * into a NOP (except for the FIFO level fetch)
+		 */
+		if (!tx_len && !rx_len) {
+			while (in_be32(&fifo->rxcnt))
+				in_8(&fifo->rxdata_8);
+		}
+
+	}
+	return 0;
+}
+
+static int mpc512x_psc_spi_msg_xfer(struct spi_master *master,
+				    struct spi_message *m)
+{
+	struct spi_device *spi;
+	unsigned cs_change;
+	int status;
+	struct spi_transfer *t;
+
+	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;
+	if (m->complete)
+		m->complete(m->context);
+
+	if (status || !cs_change)
+		mpc512x_psc_spi_deactivate_cs(spi);
+
+	mpc512x_psc_spi_transfer_setup(spi, NULL);
+
+	spi_finalize_current_message(master);
+	return status;
+}
+
+static int mpc512x_psc_spi_prep_xfer_hw(struct spi_master *master)
+{
+	struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+
+	dev_dbg(&master->dev, "%s()\n", __func__);
+
+	/* Zero MR2 */
+	in_8(&psc->mode);
+	out_8(&psc->mode, 0x0);
+
+	/* enable transmitter/receiver */
+	out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
+
+	return 0;
+}
+
+static int mpc512x_psc_spi_unprep_xfer_hw(struct spi_master *master)
+{
+	struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
+	struct mpc52xx_psc __iomem *psc = mps->psc;
+	struct mpc512x_psc_fifo __iomem *fifo = mps->fifo;
+
+	dev_dbg(&master->dev, "%s()\n", __func__);
+
+	/* disable transmitter/receiver and fifo interrupt */
+	out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
+	out_be32(&fifo->tximr, 0);
+
+	return 0;
+}
+
+static int mpc512x_psc_spi_setup(struct spi_device *spi)
+{
+	struct mpc512x_psc_spi_cs *cs = spi->controller_state;
+	int ret;
+
+	if (spi->bits_per_word % 8)
+		return -EINVAL;
+
+	if (!cs) {
+		cs = kzalloc(sizeof *cs, GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+
+		if (gpio_is_valid(spi->cs_gpio)) {
+			ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
+			if (ret) {
+				dev_err(&spi->dev, "can't get CS gpio: %d\n",
+					ret);
+				kfree(cs);
+				return ret;
+			}
+			gpio_direction_output(spi->cs_gpio,
+					spi->mode & SPI_CS_HIGH ? 0 : 1);
+		}
+
+		spi->controller_state = cs;
+	}
+
+	cs->bits_per_word = spi->bits_per_word;
+	cs->speed_hz = spi->max_speed_hz;
+
+	return 0;
+}
+
+static void mpc512x_psc_spi_cleanup(struct spi_device *spi)
+{
+	if (gpio_is_valid(spi->cs_gpio))
+		gpio_free(spi->cs_gpio);
+	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;
+	u32 sicr;
+	u32 ccr;
+	int speed;
+	u16 bclkdiv;
+
+	/* 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;
+	speed = 1000000;	/* default 1MHz */
+	bclkdiv = (mps->mclk_rate / speed) - 1;
+	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 0;
+}
+
+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 rx/tx routine */
+	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->txisrdone);
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+static void mpc512x_spi_cs_control(struct spi_device *spi, bool onoff)
+{
+	gpio_set_value(spi->cs_gpio, onoff);
+}
+
+static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
+					      u32 size, unsigned int irq)
+{
+	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
+	struct mpc512x_psc_spi *mps;
+	struct spi_master *master;
+	int ret;
+	void *tempp;
+	struct clk *clk;
+
+	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) {
+		mps->cs_control = mpc512x_spi_cs_control;
+	} else {
+		mps->cs_control = pdata->cs_control;
+		master->bus_num = pdata->bus_num;
+		master->num_chipselect = pdata->max_chipselect;
+	}
+
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+	master->setup = mpc512x_psc_spi_setup;
+	master->prepare_transfer_hardware = mpc512x_psc_spi_prep_xfer_hw;
+	master->transfer_one_message = mpc512x_psc_spi_msg_xfer;
+	master->unprepare_transfer_hardware = mpc512x_psc_spi_unprep_xfer_hw;
+	master->cleanup = mpc512x_psc_spi_cleanup;
+	master->dev.of_node = dev->of_node;
+
+	tempp = devm_ioremap(dev, 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 = devm_request_irq(dev, mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED,
+				"mpc512x-psc-spi", mps);
+	if (ret)
+		goto free_master;
+	init_completion(&mps->txisrdone);
+
+	clk = devm_clk_get(dev, "mclk");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto free_master;
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto free_master;
+	mps->clk_mclk = clk;
+	mps->mclk_rate = clk_get_rate(clk);
+
+	clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto free_mclk_clock;
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto free_mclk_clock;
+	mps->clk_ipg = clk;
+
+	ret = mpc512x_psc_spi_port_config(master, mps);
+	if (ret < 0)
+		goto free_ipg_clock;
+
+	ret = devm_spi_register_master(dev, master);
+	if (ret < 0)
+		goto free_ipg_clock;
+
+	return ret;
+
+free_ipg_clock:
+	clk_disable_unprepare(mps->clk_ipg);
+free_mclk_clock:
+	clk_disable_unprepare(mps->clk_mclk);
+free_master:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int 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);
+
+	clk_disable_unprepare(mps->clk_mclk);
+	clk_disable_unprepare(mps->clk_ipg);
+
+	return 0;
+}
+
+static int mpc512x_psc_spi_of_probe(struct platform_device *op)
+{
+	const u32 *regaddr_p;
+	u64 regaddr64, size64;
+
+	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);
+
+	return mpc512x_psc_spi_do_probe(&op->dev, (u32) regaddr64, (u32) size64,
+				irq_of_parse_and_map(op->dev.of_node, 0));
+}
+
+static int mpc512x_psc_spi_of_remove(struct platform_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 platform_driver mpc512x_psc_spi_of_driver = {
+	.probe = mpc512x_psc_spi_of_probe,
+	.remove = mpc512x_psc_spi_of_remove,
+	.driver = {
+		.name = "mpc512x-psc-spi",
+		.owner = THIS_MODULE,
+		.of_match_table = mpc512x_psc_spi_of_match,
+	},
+};
+module_platform_driver(mpc512x_psc_spi_of_driver);
+
+MODULE_AUTHOR("John Rigby");
+MODULE_DESCRIPTION("MPC512x PSC SPI Driver");
+MODULE_LICENSE("GPL");