linux/drivers/spi/spi-mpc512x-psc.c
Gerhard Sittig 85085898ab spi: mpc512x: use the SPI subsystem's message queue
the SPI subsystem recently grew support to queue messages before handing
them to the SPI master, and erroneously emitted deprecation warnings
when the SPI master's driver did not use the common logic (in fact the
master might queue messages, but implement the queue in the master
driver's source)

  [    0.823015] mpc512x-psc-spi 80011400.psc: master is unqueued, this is deprecated
  [    0.854913] mpc512x-psc-spi 80011500.psc: master is unqueued, this is deprecated

this change makes the MPC512x PSC SPI driver use the SPI subsystem's
support to queue SPI messages and removes the master driver's private
code for the queue support

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-06-04 18:22:48 +01:00

609 lines
16 KiB
C

/*
* 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/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/of_address.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;
u32 mclk;
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;
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;
if (cs->speed_hz)
bclkdiv = (mps->mclk / cs->speed_hz) - 1;
else
bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */
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 */
INIT_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;
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;
struct clk *spiclk;
int ret = 0;
char name[32];
u32 sicr;
u32 ccr;
u16 bclkdiv;
sprintf(name, "psc%d_mclk", master->bus_num);
spiclk = clk_get(&master->dev, name);
clk_enable(spiclk);
mps->mclk = clk_get_rate(spiclk);
clk_put(spiclk);
/* 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;
bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */
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 ret;
}
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);
}
/* bus_num is used only for the case dev->platform_data == NULL */
static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
u32 size, unsigned int irq,
s16 bus_num)
{
struct fsl_spi_platform_data *pdata = dev->platform_data;
struct mpc512x_psc_spi *mps;
struct spi_master *master;
int ret;
void *tempp;
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;
master->bus_num = bus_num;
} 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 = ioremap(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 = request_irq(mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED,
"mpc512x-psc-spi", mps);
if (ret)
goto free_master;
init_completion(&mps->txisrdone);
ret = mpc512x_psc_spi_port_config(master, mps);
if (ret < 0)
goto free_irq;
ret = spi_register_master(master);
if (ret < 0)
goto free_irq;
return ret;
free_irq:
free_irq(mps->irq, mps);
free_master:
if (mps->psc)
iounmap(mps->psc);
spi_master_put(master);
return ret;
}
static int mpc512x_psc_spi_do_remove(struct device *dev)
{
struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
spi_unregister_master(master);
free_irq(mps->irq, mps);
if (mps->psc)
iounmap(mps->psc);
spi_master_put(master);
return 0;
}
static int mpc512x_psc_spi_of_probe(struct platform_device *op)
{
const u32 *regaddr_p;
u64 regaddr64, size64;
s16 id = -1;
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);
/* get PSC id (0..11, used by port_config) */
id = of_alias_get_id(op->dev.of_node, "spi");
if (id < 0) {
dev_err(&op->dev, "no alias id for %s\n",
op->dev.of_node->full_name);
return id;
}
return mpc512x_psc_spi_do_probe(&op->dev, (u32) regaddr64, (u32) size64,
irq_of_parse_and_map(op->dev.of_node, 0), id);
}
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");