spi-fsl-cpm.c
/*
* 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 <asm/cpm.h>
#include <asm/qe.h>
#include <linux/dma-mapping.h>
#include <linux/fsl_devices.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include "spi-fsl-cpm.h"
#include "spi-fsl-lib.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 {
if (mspi->flags & SPI_CPM1) {
out_be32(&mspi->pram->rstate, 0);
out_be16(&mspi->pram->rbptr,
in_be16(&mspi->pram->rbase));
out_be32(&mspi->pram->tstate, 0);
out_be16(&mspi->pram->tbptr,
in_be16(&mspi->pram->tbase));
} else {
cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
}
}
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_reinit_txrx);
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(®_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(®_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;
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs);
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;
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs_complete);
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(®_base->event, events);
mspi->count -= len;
if (mspi->count)
fsl_spi_cpm_bufs_start(mspi);
else
complete(&mspi->done);
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_irq);
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);
}
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 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\n");
/* fall through */
case 0:
mspi->subblock = QE_CR_SUBBLOCK_SPI1;
break;
case 1:
mspi->subblock = QE_CR_SUBBLOCK_SPI2;
break;
}
}
if (mspi->flags & SPI_CPM1) {
struct resource *res;
void *pram;
res = platform_get_resource(to_platform_device(dev),
IORESOURCE_MEM, 1);
pram = devm_ioremap_resource(dev, res);
if (IS_ERR(pram))
mspi->pram = NULL;
else
mspi->pram = pram;
} else {
unsigned long pram_ofs = fsl_spi_cpm_get_pram(mspi);
if (IS_ERR_VALUE(pram_ofs))
mspi->pram = NULL;
else
mspi->pram = cpm_muram_addr(pram_ofs);
}
if (mspi->pram == NULL) {
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->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:
if (!(mspi->flags & SPI_CPM1))
cpm_muram_free(cpm_muram_offset(mspi->pram));
err_pram:
fsl_spi_free_dummy_rx();
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_init);
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();
}
EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);
MODULE_LICENSE("GPL");