linux/drivers/spi/spi-mpc52xx-psc.c
Mark Brown 145cfc3840
spi: mpc52xx-psc: Switch to using core message queue
We deprecated open coding of the transfer queue back in 2017 so it's high
time we finished up converting drivers to use the standard message queue
code. The mpc52xx-psc driver is fairly straightforward so convert to use
transfer_one_message(), it looks like the driver would be a good fit for
transfer_one() with a little bit of updating but this smaller change seems
safer.

The driver seems like a good candidate for transfer_one() but the chip
select function is actually doing rather more than just updating the chip
select and both transfer_one() and transfer_one_message() are current APIs
so leave that refactoring for another day, ideally by someone with the
hardware.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220613121946.136193-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-06-27 13:24:36 +01:00

456 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* MPC52xx PSC in SPI mode driver.
*
* Maintainer: Dragos Carp
*
* Copyright (C) 2006 TOPTICA Photonics AG.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <linux/fsl_devices.h>
#include <linux/slab.h>
#include <linux/of_irq.h>
#include <asm/mpc52xx.h>
#include <asm/mpc52xx_psc.h>
#define MCLK 20000000 /* PSC port MClk in hz */
struct mpc52xx_psc_spi {
/* fsl_spi_platform data */
void (*cs_control)(struct spi_device *spi, bool on);
u32 sysclk;
/* driver internal data */
struct mpc52xx_psc __iomem *psc;
struct mpc52xx_psc_fifo __iomem *fifo;
unsigned int irq;
u8 bits_per_word;
struct completion done;
};
/* controller state */
struct mpc52xx_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 mpc52xx_psc_spi_transfer_setup(struct spi_device *spi,
struct spi_transfer *t)
{
struct mpc52xx_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 mpc52xx_psc_spi_activate_cs(struct spi_device *spi)
{
struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
struct mpc52xx_psc __iomem *psc = mps->psc;
u32 sicr;
u16 ccr;
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);
/* Set clock frequency and bits per word
* Because psc->ccr is defined as 16bit register instead of 32bit
* just set the lower byte of BitClkDiv
*/
ccr = in_be16((u16 __iomem *)&psc->ccr);
ccr &= 0xFF00;
if (cs->speed_hz)
ccr |= (MCLK / cs->speed_hz - 1) & 0xFF;
else /* by default SPI Clk 1MHz */
ccr |= (MCLK / 1000000 - 1) & 0xFF;
out_be16((u16 __iomem *)&psc->ccr, ccr);
mps->bits_per_word = cs->bits_per_word;
if (mps->cs_control)
mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
}
static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi)
{
struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
if (mps->cs_control)
mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
}
#define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1)
/* wake up when 80% fifo full */
#define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100)
static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi,
struct spi_transfer *t)
{
struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master);
struct mpc52xx_psc __iomem *psc = mps->psc;
struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
unsigned rb = 0; /* number of bytes receieved */
unsigned sb = 0; /* number of bytes sent */
unsigned char *rx_buf = (unsigned char *)t->rx_buf;
unsigned char *tx_buf = (unsigned char *)t->tx_buf;
unsigned rfalarm;
unsigned send_at_once = MPC52xx_PSC_BUFSIZE;
unsigned recv_at_once;
int last_block = 0;
if (!t->tx_buf && !t->rx_buf && t->len)
return -EINVAL;
/* enable transmiter/receiver */
out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
while (rb < t->len) {
if (t->len - rb > MPC52xx_PSC_BUFSIZE) {
rfalarm = MPC52xx_PSC_RFALARM;
last_block = 0;
} else {
send_at_once = t->len - sb;
rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb);
last_block = 1;
}
dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once);
for (; send_at_once; sb++, send_at_once--) {
/* set EOF flag before the last word is sent */
if (send_at_once == 1 && last_block)
out_8(&psc->ircr2, 0x01);
if (tx_buf)
out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]);
else
out_8(&psc->mpc52xx_psc_buffer_8, 0);
}
/* enable interrupts and wait for wake up
* if just one byte is expected the Rx FIFO genererates no
* FFULL interrupt, so activate the RxRDY interrupt
*/
out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
if (t->len - rb == 1) {
out_8(&psc->mode, 0);
} else {
out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
out_be16(&fifo->rfalarm, rfalarm);
}
out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY);
wait_for_completion(&mps->done);
recv_at_once = in_be16(&fifo->rfnum);
dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once);
send_at_once = recv_at_once;
if (rx_buf) {
for (; recv_at_once; rb++, recv_at_once--)
rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8);
} else {
for (; recv_at_once; rb++, recv_at_once--)
in_8(&psc->mpc52xx_psc_buffer_8);
}
}
/* disable transmiter/receiver */
out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE);
return 0;
}
int mpc52xx_psc_spi_transfer_one_message(struct spi_controller *ctlr,
struct spi_message *m)
{
struct spi_device *spi;
struct spi_transfer *t = NULL;
unsigned cs_change;
int status;
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 = mpc52xx_psc_spi_transfer_setup(spi, t);
if (status < 0)
break;
}
if (cs_change)
mpc52xx_psc_spi_activate_cs(spi);
cs_change = t->cs_change;
status = mpc52xx_psc_spi_transfer_rxtx(spi, t);
if (status)
break;
m->actual_length += t->len;
spi_transfer_delay_exec(t);
if (cs_change)
mpc52xx_psc_spi_deactivate_cs(spi);
}
m->status = status;
if (status || !cs_change)
mpc52xx_psc_spi_deactivate_cs(spi);
mpc52xx_psc_spi_transfer_setup(spi, NULL);
spi_finalize_current_message(ctlr);
return 0;
}
static int mpc52xx_psc_spi_setup(struct spi_device *spi)
{
struct mpc52xx_psc_spi_cs *cs = spi->controller_state;
if (spi->bits_per_word%8)
return -EINVAL;
if (!cs) {
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return -ENOMEM;
spi->controller_state = cs;
}
cs->bits_per_word = spi->bits_per_word;
cs->speed_hz = spi->max_speed_hz;
return 0;
}
static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
{
kfree(spi->controller_state);
}
static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
{
struct mpc52xx_psc __iomem *psc = mps->psc;
struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
u32 mclken_div;
int ret;
/* default sysclk is 512MHz */
mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
if (ret)
return ret;
/* 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 interrupts, interrupts are based on alarm level */
out_be16(&psc->mpc52xx_psc_imr, 0);
out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
out_8(&fifo->rfcntl, 0);
out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL);
/* Configure 8bit codec mode as a SPI master and use EOF flags */
/* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */
out_be32(&psc->sicr, 0x0180C800);
out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */
/* Set 2ms DTL delay */
out_8(&psc->ctur, 0x00);
out_8(&psc->ctlr, 0x84);
mps->bits_per_word = 8;
return 0;
}
static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id)
{
struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id;
struct mpc52xx_psc __iomem *psc = mps->psc;
/* disable interrupt and wake up the work queue */
if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) {
out_be16(&psc->mpc52xx_psc_imr, 0);
complete(&mps->done);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/* bus_num is used only for the case dev->platform_data == NULL */
static int mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr,
u32 size, unsigned int irq, s16 bus_num)
{
struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
struct mpc52xx_psc_spi *mps;
struct spi_master *master;
int ret;
master = spi_alloc_master(dev, sizeof(*mps));
if (master == NULL)
return -ENOMEM;
dev_set_drvdata(dev, master);
mps = spi_master_get_devdata(master);
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
mps->irq = irq;
if (pdata == NULL) {
dev_warn(dev,
"probe called without platform data, no cs_control function will be called\n");
mps->cs_control = NULL;
mps->sysclk = 0;
master->bus_num = bus_num;
master->num_chipselect = 255;
} else {
mps->cs_control = pdata->cs_control;
mps->sysclk = pdata->sysclk;
master->bus_num = pdata->bus_num;
master->num_chipselect = pdata->max_chipselect;
}
master->setup = mpc52xx_psc_spi_setup;
master->transfer_one_message = mpc52xx_psc_spi_transfer_one_message;
master->cleanup = mpc52xx_psc_spi_cleanup;
master->dev.of_node = dev->of_node;
mps->psc = ioremap(regaddr, size);
if (!mps->psc) {
dev_err(dev, "could not ioremap I/O port range\n");
ret = -EFAULT;
goto free_master;
}
/* On the 5200, fifo regs are immediately ajacent to the psc regs */
mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc);
ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi",
mps);
if (ret)
goto free_master;
ret = mpc52xx_psc_spi_port_config(master->bus_num, mps);
if (ret < 0) {
dev_err(dev, "can't configure PSC! Is it capable of SPI?\n");
goto free_irq;
}
init_completion(&mps->done);
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 mpc52xx_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 (1..6, used by port_config) */
if (op->dev.platform_data == NULL) {
const u32 *psc_nump;
psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL);
if (!psc_nump || *psc_nump > 5) {
dev_err(&op->dev, "Invalid cell-index property\n");
return -EINVAL;
}
id = *psc_nump + 1;
}
return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64,
irq_of_parse_and_map(op->dev.of_node, 0), id);
}
static int mpc52xx_psc_spi_of_remove(struct platform_device *op)
{
struct spi_master *master = spi_master_get(platform_get_drvdata(op));
struct mpc52xx_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 const struct of_device_id mpc52xx_psc_spi_of_match[] = {
{ .compatible = "fsl,mpc5200-psc-spi", },
{ .compatible = "mpc5200-psc-spi", }, /* old */
{}
};
MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match);
static struct platform_driver mpc52xx_psc_spi_of_driver = {
.probe = mpc52xx_psc_spi_of_probe,
.remove = mpc52xx_psc_spi_of_remove,
.driver = {
.name = "mpc52xx-psc-spi",
.of_match_table = mpc52xx_psc_spi_of_match,
},
};
module_platform_driver(mpc52xx_psc_spi_of_driver);
MODULE_AUTHOR("Dragos Carp");
MODULE_DESCRIPTION("MPC52xx PSC SPI Driver");
MODULE_LICENSE("GPL");