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linux_dsm_epyc7002/drivers/spi/spi-altera.c
Xu Yilun 1fccd182a4
spi: altera: add platform data for slave information. 
This patch introduces platform data for slave information, it allows
spi-altera to add new spi devices once master registration is done.

Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/1591845911-10197-4-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-15 23:36:03 +01:00

289 lines
6.7 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Altera SPI driver
*
* Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
*
* Based on spi_s3c24xx.c, which is:
* Copyright (c) 2006 Ben Dooks
* Copyright (c) 2006 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*/
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/altera.h>
#include <linux/spi/spi.h>
#include <linux/io.h>
#include <linux/of.h>
#define DRV_NAME "spi_altera"
#define ALTERA_SPI_RXDATA 0
#define ALTERA_SPI_TXDATA 4
#define ALTERA_SPI_STATUS 8
#define ALTERA_SPI_CONTROL 12
#define ALTERA_SPI_SLAVE_SEL 20
#define ALTERA_SPI_STATUS_ROE_MSK 0x8
#define ALTERA_SPI_STATUS_TOE_MSK 0x10
#define ALTERA_SPI_STATUS_TMT_MSK 0x20
#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
#define ALTERA_SPI_STATUS_E_MSK 0x100
#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
#define ALTERA_SPI_CONTROL_IE_MSK 0x100
#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
#define ALTERA_SPI_MAX_CS 32
struct altera_spi {
void __iomem *base;
int irq;
int len;
int count;
int bytes_per_word;
unsigned long imr;
/* data buffers */
const unsigned char *tx;
unsigned char *rx;
};
static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
{
return spi_master_get_devdata(sdev->master);
}
static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
{
struct altera_spi *hw = altera_spi_to_hw(spi);
if (is_high) {
hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
} else {
writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
}
}
static void altera_spi_tx_word(struct altera_spi *hw)
{
unsigned int txd = 0;
if (hw->tx) {
switch (hw->bytes_per_word) {
case 1:
txd = hw->tx[hw->count];
break;
case 2:
txd = (hw->tx[hw->count * 2]
| (hw->tx[hw->count * 2 + 1] << 8));
break;
case 4:
txd = (hw->tx[hw->count * 4]
| (hw->tx[hw->count * 4 + 1] << 8)
| (hw->tx[hw->count * 4 + 2] << 16)
| (hw->tx[hw->count * 4 + 3] << 24));
break;
}
}
writel(txd, hw->base + ALTERA_SPI_TXDATA);
}
static void altera_spi_rx_word(struct altera_spi *hw)
{
unsigned int rxd;
rxd = readl(hw->base + ALTERA_SPI_RXDATA);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
hw->rx[hw->count] = rxd;
break;
case 2:
hw->rx[hw->count * 2] = rxd;
hw->rx[hw->count * 2 + 1] = rxd >> 8;
break;
case 4:
hw->rx[hw->count * 4] = rxd;
hw->rx[hw->count * 4 + 1] = rxd >> 8;
hw->rx[hw->count * 4 + 2] = rxd >> 16;
hw->rx[hw->count * 4 + 3] = rxd >> 24;
break;
}
}
hw->count++;
}
static int altera_spi_txrx(struct spi_master *master,
struct spi_device *spi, struct spi_transfer *t)
{
struct altera_spi *hw = spi_master_get_devdata(master);
hw->tx = t->tx_buf;
hw->rx = t->rx_buf;
hw->count = 0;
hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
hw->len = t->len / hw->bytes_per_word;
if (hw->irq >= 0) {
/* enable receive interrupt */
hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
/* send the first byte */
altera_spi_tx_word(hw);
} else {
while (hw->count < hw->len) {
altera_spi_tx_word(hw);
while (!(readl(hw->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
cpu_relax();
altera_spi_rx_word(hw);
}
spi_finalize_current_transfer(master);
}
return t->len;
}
static irqreturn_t altera_spi_irq(int irq, void *dev)
{
struct spi_master *master = dev;
struct altera_spi *hw = spi_master_get_devdata(master);
altera_spi_rx_word(hw);
if (hw->count < hw->len) {
altera_spi_tx_word(hw);
} else {
/* disable receive interrupt */
hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
spi_finalize_current_transfer(master);
}
return IRQ_HANDLED;
}
static int altera_spi_probe(struct platform_device *pdev)
{
struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct altera_spi *hw;
struct spi_master *master;
int err = -ENODEV;
u16 i;
master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
if (!master)
return err;
/* setup the master state. */
master->bus_num = pdev->id;
if (pdata) {
if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
dev_err(&pdev->dev,
"Invalid number of chipselect: %hu\n",
pdata->num_chipselect);
return -EINVAL;
}
master->num_chipselect = pdata->num_chipselect;
master->mode_bits = pdata->mode_bits;
master->bits_per_word_mask = pdata->bits_per_word_mask;
} else {
master->num_chipselect = 16;
master->mode_bits = SPI_CS_HIGH;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
}
master->dev.of_node = pdev->dev.of_node;
master->transfer_one = altera_spi_txrx;
master->set_cs = altera_spi_set_cs;
hw = spi_master_get_devdata(master);
/* find and map our resources */
hw->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hw->base)) {
err = PTR_ERR(hw->base);
goto exit;
}
/* program defaults into the registers */
hw->imr = 0; /* disable spi interrupts */
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
/* irq is optional */
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq >= 0) {
err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
pdev->name, master);
if (err)
goto exit;
}
err = devm_spi_register_master(&pdev->dev, master);
if (err)
goto exit;
if (pdata) {
for (i = 0; i < pdata->num_devices; i++) {
if (!spi_new_device(master, pdata->devices + i))
dev_warn(&pdev->dev,
"unable to create SPI device: %s\n",
pdata->devices[i].modalias);
}
}
dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
return 0;
exit:
spi_master_put(master);
return err;
}
#ifdef CONFIG_OF
static const struct of_device_id altera_spi_match[] = {
{ .compatible = "ALTR,spi-1.0", },
{ .compatible = "altr,spi-1.0", },
{},
};
MODULE_DEVICE_TABLE(of, altera_spi_match);
#endif /* CONFIG_OF */
static struct platform_driver altera_spi_driver = {
.probe = altera_spi_probe,
.driver = {
.name = DRV_NAME,
.pm = NULL,
.of_match_table = of_match_ptr(altera_spi_match),
},
};
module_platform_driver(altera_spi_driver);
MODULE_DESCRIPTION("Altera SPI driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
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