spi/spi-fsl-spi: Make driver usable in CPU mode outside of an FSL_SOC environment

This makes the spi-fsl-spi driver usable in CPU mode outside of an FSL_SOC and
even an powerpc environment by moving CPM mode functionality to a separate file
that is only compiled and linked in an FSL_SOC environment and adding some
ifdefs to hide types and functions or provide alternatives.

For devicetree probing a "clock-frequency" property is used for clock frequency
instead of calls to FSL_SOC-specific functions.

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 387 insertions, 0 deletions

diff --git a/drivers/spi/spi-fsl-cpm.c b/drivers/spi/spi-fsl-cpm.c
new file mode 100644
index 000000000000..07971e3fe58b
--- /dev/null
+++ b/drivers/spi/spi-fsl-cpm.c
@@ -0,0 +1,387 @@
+/*
+ * Freescale SPI controller driver cpm functions.
+ *
+ * Maintainer: Kumar Gala
+ *
+ * Copyright (C) 2006 Polycom, Inc.
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * CPM SPI and QE buffer descriptors mode support:
+ * Copyright (c) 2009  MontaVista Software, Inc.
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.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.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/fsl_devices.h>
+#include <linux/dma-mapping.h>
+#include <asm/cpm.h>
+#include <asm/qe.h>
+
+#include "spi-fsl-lib.h"
+#include "spi-fsl-cpm.h"
+#include "spi-fsl-spi.h"
+
+/* CPM1 and CPM2 are mutually exclusive. */
+#ifdef CONFIG_CPM1
+#include <asm/cpm1.h>
+#define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
+#else
+#include <asm/cpm2.h>
+#define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
+#endif
+
+#define	SPIE_TXB	0x00000200	/* Last char is written to tx fifo */
+#define	SPIE_RXB	0x00000100	/* Last char is written to rx buf */
+
+/* SPCOM register values */
+#define	SPCOM_STR	(1 << 23)	/* Start transmit */
+
+#define	SPI_PRAM_SIZE	0x100
+#define	SPI_MRBLR	((unsigned int)PAGE_SIZE)
+
+static void *fsl_dummy_rx;
+static DEFINE_MUTEX(fsl_dummy_rx_lock);
+static int fsl_dummy_rx_refcnt;
+
+void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
+{
+	if (mspi->flags & SPI_QE) {
+		qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
+			     QE_CR_PROTOCOL_UNSPECIFIED, 0);
+	} else {
+		cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
+		if (mspi->flags & SPI_CPM1) {
+			out_be16(&mspi->pram->rbptr,
+				 in_be16(&mspi->pram->rbase));
+			out_be16(&mspi->pram->tbptr,
+				 in_be16(&mspi->pram->tbase));
+		}
+	}
+}
+
+static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
+{
+	struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
+	struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
+	unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
+	unsigned int xfer_ofs;
+	struct fsl_spi_reg *reg_base = mspi->reg_base;
+
+	xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
+
+	if (mspi->rx_dma == mspi->dma_dummy_rx)
+		out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma);
+	else
+		out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma + xfer_ofs);
+	out_be16(&rx_bd->cbd_datlen, 0);
+	out_be16(&rx_bd->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP);
+
+	if (mspi->tx_dma == mspi->dma_dummy_tx)
+		out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma);
+	else
+		out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma + xfer_ofs);
+	out_be16(&tx_bd->cbd_datlen, xfer_len);
+	out_be16(&tx_bd->cbd_sc, BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP |
+				 BD_SC_LAST);
+
+	/* start transfer */
+	mpc8xxx_spi_write_reg(&reg_base->command, SPCOM_STR);
+}
+
+int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi,
+		     struct spi_transfer *t, bool is_dma_mapped)
+{
+	struct device *dev = mspi->dev;
+	struct fsl_spi_reg *reg_base = mspi->reg_base;
+
+	if (is_dma_mapped) {
+		mspi->map_tx_dma = 0;
+		mspi->map_rx_dma = 0;
+	} else {
+		mspi->map_tx_dma = 1;
+		mspi->map_rx_dma = 1;
+	}
+
+	if (!t->tx_buf) {
+		mspi->tx_dma = mspi->dma_dummy_tx;
+		mspi->map_tx_dma = 0;
+	}
+
+	if (!t->rx_buf) {
+		mspi->rx_dma = mspi->dma_dummy_rx;
+		mspi->map_rx_dma = 0;
+	}
+
+	if (mspi->map_tx_dma) {
+		void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
+
+		mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
+					      DMA_TO_DEVICE);
+		if (dma_mapping_error(dev, mspi->tx_dma)) {
+			dev_err(dev, "unable to map tx dma\n");
+			return -ENOMEM;
+		}
+	} else if (t->tx_buf) {
+		mspi->tx_dma = t->tx_dma;
+	}
+
+	if (mspi->map_rx_dma) {
+		mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
+					      DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, mspi->rx_dma)) {
+			dev_err(dev, "unable to map rx dma\n");
+			goto err_rx_dma;
+		}
+	} else if (t->rx_buf) {
+		mspi->rx_dma = t->rx_dma;
+	}
+
+	/* enable rx ints */
+	mpc8xxx_spi_write_reg(&reg_base->mask, SPIE_RXB);
+
+	mspi->xfer_in_progress = t;
+	mspi->count = t->len;
+
+	/* start CPM transfers */
+	fsl_spi_cpm_bufs_start(mspi);
+
+	return 0;
+
+err_rx_dma:
+	if (mspi->map_tx_dma)
+		dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
+	return -ENOMEM;
+}
+
+void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
+{
+	struct device *dev = mspi->dev;
+	struct spi_transfer *t = mspi->xfer_in_progress;
+
+	if (mspi->map_tx_dma)
+		dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
+	if (mspi->map_rx_dma)
+		dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
+	mspi->xfer_in_progress = NULL;
+}
+
+void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
+{
+	u16 len;
+	struct fsl_spi_reg *reg_base = mspi->reg_base;
+
+	dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
+		in_be16(&mspi->rx_bd->cbd_datlen), mspi->count);
+
+	len = in_be16(&mspi->rx_bd->cbd_datlen);
+	if (len > mspi->count) {
+		WARN_ON(1);
+		len = mspi->count;
+	}
+
+	/* Clear the events */
+	mpc8xxx_spi_write_reg(&reg_base->event, events);
+
+	mspi->count -= len;
+	if (mspi->count)
+		fsl_spi_cpm_bufs_start(mspi);
+	else
+		complete(&mspi->done);
+}
+
+static void *fsl_spi_alloc_dummy_rx(void)
+{
+	mutex_lock(&fsl_dummy_rx_lock);
+
+	if (!fsl_dummy_rx)
+		fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
+	if (fsl_dummy_rx)
+		fsl_dummy_rx_refcnt++;
+
+	mutex_unlock(&fsl_dummy_rx_lock);
+
+	return fsl_dummy_rx;
+}
+
+static void fsl_spi_free_dummy_rx(void)
+{
+	mutex_lock(&fsl_dummy_rx_lock);
+
+	switch (fsl_dummy_rx_refcnt) {
+	case 0:
+		WARN_ON(1);
+		break;
+	case 1:
+		kfree(fsl_dummy_rx);
+		fsl_dummy_rx = NULL;
+		/* fall through */
+	default:
+		fsl_dummy_rx_refcnt--;
+		break;
+	}
+
+	mutex_unlock(&fsl_dummy_rx_lock);
+}
+
+static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
+{
+	struct device *dev = mspi->dev;
+	struct device_node *np = dev->of_node;
+	const u32 *iprop;
+	int size;
+	void __iomem *spi_base;
+	unsigned long pram_ofs = -ENOMEM;
+
+	/* Can't use of_address_to_resource(), QE muram isn't at 0. */
+	iprop = of_get_property(np, "reg", &size);
+
+	/* QE with a fixed pram location? */
+	if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
+		return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
+
+	/* QE but with a dynamic pram location? */
+	if (mspi->flags & SPI_QE) {
+		pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
+		qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
+			     QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
+		return pram_ofs;
+	}
+
+	spi_base = of_iomap(np, 1);
+	if (spi_base == NULL)
+		return -EINVAL;
+
+	if (mspi->flags & SPI_CPM2) {
+		pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
+		out_be16(spi_base, pram_ofs);
+	} else {
+		struct spi_pram __iomem *pram = spi_base;
+		u16 rpbase = in_be16(&pram->rpbase);
+
+		/* Microcode relocation patch applied? */
+		if (rpbase) {
+			pram_ofs = rpbase;
+		} else {
+			pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
+			out_be16(spi_base, pram_ofs);
+		}
+	}
+
+	iounmap(spi_base);
+	return pram_ofs;
+}
+
+int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
+{
+	struct device *dev = mspi->dev;
+	struct device_node *np = dev->of_node;
+	const u32 *iprop;
+	int size;
+	unsigned long pram_ofs;
+	unsigned long bds_ofs;
+
+	if (!(mspi->flags & SPI_CPM_MODE))
+		return 0;
+
+	if (!fsl_spi_alloc_dummy_rx())
+		return -ENOMEM;
+
+	if (mspi->flags & SPI_QE) {
+		iprop = of_get_property(np, "cell-index", &size);
+		if (iprop && size == sizeof(*iprop))
+			mspi->subblock = *iprop;
+
+		switch (mspi->subblock) {
+		default:
+			dev_warn(dev, "cell-index unspecified, assuming SPI1");
+			/* fall through */
+		case 0:
+			mspi->subblock = QE_CR_SUBBLOCK_SPI1;
+			break;
+		case 1:
+			mspi->subblock = QE_CR_SUBBLOCK_SPI2;
+			break;
+		}
+	}
+
+	pram_ofs = fsl_spi_cpm_get_pram(mspi);
+	if (IS_ERR_VALUE(pram_ofs)) {
+		dev_err(dev, "can't allocate spi parameter ram\n");
+		goto err_pram;
+	}
+
+	bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
+				  sizeof(*mspi->rx_bd), 8);
+	if (IS_ERR_VALUE(bds_ofs)) {
+		dev_err(dev, "can't allocate bds\n");
+		goto err_bds;
+	}
+
+	mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE,
+					    DMA_TO_DEVICE);
+	if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
+		dev_err(dev, "unable to map dummy tx buffer\n");
+		goto err_dummy_tx;
+	}
+
+	mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
+					    DMA_FROM_DEVICE);
+	if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
+		dev_err(dev, "unable to map dummy rx buffer\n");
+		goto err_dummy_rx;
+	}
+
+	mspi->pram = cpm_muram_addr(pram_ofs);
+
+	mspi->tx_bd = cpm_muram_addr(bds_ofs);
+	mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
+
+	/* Initialize parameter ram. */
+	out_be16(&mspi->pram->tbase, cpm_muram_offset(mspi->tx_bd));
+	out_be16(&mspi->pram->rbase, cpm_muram_offset(mspi->rx_bd));
+	out_8(&mspi->pram->tfcr, CPMFCR_EB | CPMFCR_GBL);
+	out_8(&mspi->pram->rfcr, CPMFCR_EB | CPMFCR_GBL);
+	out_be16(&mspi->pram->mrblr, SPI_MRBLR);
+	out_be32(&mspi->pram->rstate, 0);
+	out_be32(&mspi->pram->rdp, 0);
+	out_be16(&mspi->pram->rbptr, 0);
+	out_be16(&mspi->pram->rbc, 0);
+	out_be32(&mspi->pram->rxtmp, 0);
+	out_be32(&mspi->pram->tstate, 0);
+	out_be32(&mspi->pram->tdp, 0);
+	out_be16(&mspi->pram->tbptr, 0);
+	out_be16(&mspi->pram->tbc, 0);
+	out_be32(&mspi->pram->txtmp, 0);
+
+	return 0;
+
+err_dummy_rx:
+	dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
+err_dummy_tx:
+	cpm_muram_free(bds_ofs);
+err_bds:
+	cpm_muram_free(pram_ofs);
+err_pram:
+	fsl_spi_free_dummy_rx();
+	return -ENOMEM;
+}
+
+void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
+{
+	struct device *dev = mspi->dev;
+
+	if (!(mspi->flags & SPI_CPM_MODE))
+		return;
+
+	dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
+	dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
+	cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
+	cpm_muram_free(cpm_muram_offset(mspi->pram));
+	fsl_spi_free_dummy_rx();
+}