Contributors: 12
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Gabor Juhos |
959 |
85.40% |
6 |
27.27% |
| Alban Bedel |
95 |
8.46% |
5 |
22.73% |
| Jingoo Han |
12 |
1.07% |
2 |
9.09% |
| Felix Fietkau |
12 |
1.07% |
1 |
4.55% |
| Stephen Warren |
11 |
0.98% |
1 |
4.55% |
| Heiner Kallweit |
10 |
0.89% |
1 |
4.55% |
| Javier Martinez Canillas |
7 |
0.62% |
1 |
4.55% |
| Linus Walleij |
6 |
0.53% |
1 |
4.55% |
| Aravind Thokala |
5 |
0.45% |
1 |
4.55% |
| Lorenzo Bianconi |
3 |
0.27% |
1 |
4.55% |
| Thomas Gleixner |
2 |
0.18% |
1 |
4.55% |
| Grant C. Likely |
1 |
0.09% |
1 |
4.55% |
| Total |
1123 |
|
22 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* SPI controller driver for the Atheros AR71XX/AR724X/AR913X SoCs
*
* Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
*
* This driver has been based on the spi-gpio.c:
* Copyright (C) 2006,2008 David Brownell
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_data/spi-ath79.h>
#define DRV_NAME "ath79-spi"
#define ATH79_SPI_RRW_DELAY_FACTOR 12000
#define MHZ (1000 * 1000)
#define AR71XX_SPI_REG_FS 0x00 /* Function Select */
#define AR71XX_SPI_REG_CTRL 0x04 /* SPI Control */
#define AR71XX_SPI_REG_IOC 0x08 /* SPI I/O Control */
#define AR71XX_SPI_REG_RDS 0x0c /* Read Data Shift */
#define AR71XX_SPI_FS_GPIO BIT(0) /* Enable GPIO mode */
#define AR71XX_SPI_IOC_DO BIT(0) /* Data Out pin */
#define AR71XX_SPI_IOC_CLK BIT(8) /* CLK pin */
#define AR71XX_SPI_IOC_CS(n) BIT(16 + (n))
struct ath79_spi {
struct spi_bitbang bitbang;
u32 ioc_base;
u32 reg_ctrl;
void __iomem *base;
struct clk *clk;
unsigned int rrw_delay;
};
static inline u32 ath79_spi_rr(struct ath79_spi *sp, unsigned int reg)
{
return ioread32(sp->base + reg);
}
static inline void ath79_spi_wr(struct ath79_spi *sp, unsigned int reg, u32 val)
{
iowrite32(val, sp->base + reg);
}
static inline struct ath79_spi *ath79_spidev_to_sp(struct spi_device *spi)
{
return spi_master_get_devdata(spi->master);
}
static inline void ath79_spi_delay(struct ath79_spi *sp, unsigned int nsecs)
{
if (nsecs > sp->rrw_delay)
ndelay(nsecs - sp->rrw_delay);
}
static void ath79_spi_chipselect(struct spi_device *spi, int is_active)
{
struct ath79_spi *sp = ath79_spidev_to_sp(spi);
int cs_high = (spi->mode & SPI_CS_HIGH) ? is_active : !is_active;
u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
if (cs_high)
sp->ioc_base |= cs_bit;
else
sp->ioc_base &= ~cs_bit;
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
}
static void ath79_spi_enable(struct ath79_spi *sp)
{
/* enable GPIO mode */
ath79_spi_wr(sp, AR71XX_SPI_REG_FS, AR71XX_SPI_FS_GPIO);
/* save CTRL register */
sp->reg_ctrl = ath79_spi_rr(sp, AR71XX_SPI_REG_CTRL);
sp->ioc_base = ath79_spi_rr(sp, AR71XX_SPI_REG_IOC);
/* clear clk and mosi in the base state */
sp->ioc_base &= ~(AR71XX_SPI_IOC_DO | AR71XX_SPI_IOC_CLK);
/* TODO: setup speed? */
ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, 0x43);
}
static void ath79_spi_disable(struct ath79_spi *sp)
{
/* restore CTRL register */
ath79_spi_wr(sp, AR71XX_SPI_REG_CTRL, sp->reg_ctrl);
/* disable GPIO mode */
ath79_spi_wr(sp, AR71XX_SPI_REG_FS, 0);
}
static u32 ath79_spi_txrx_mode0(struct spi_device *spi, unsigned int nsecs,
u32 word, u8 bits, unsigned flags)
{
struct ath79_spi *sp = ath79_spidev_to_sp(spi);
u32 ioc = sp->ioc_base;
/* clock starts at inactive polarity */
for (word <<= (32 - bits); likely(bits); bits--) {
u32 out;
if (word & (1 << 31))
out = ioc | AR71XX_SPI_IOC_DO;
else
out = ioc & ~AR71XX_SPI_IOC_DO;
/* setup MSB (to slave) on trailing edge */
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
ath79_spi_delay(sp, nsecs);
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
ath79_spi_delay(sp, nsecs);
if (bits == 1)
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
word <<= 1;
}
return ath79_spi_rr(sp, AR71XX_SPI_REG_RDS);
}
static int ath79_spi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct ath79_spi *sp;
struct ath79_spi_platform_data *pdata;
struct resource *r;
unsigned long rate;
int ret;
master = spi_alloc_master(&pdev->dev, sizeof(*sp));
if (master == NULL) {
dev_err(&pdev->dev, "failed to allocate spi master\n");
return -ENOMEM;
}
sp = spi_master_get_devdata(master);
master->dev.of_node = pdev->dev.of_node;
platform_set_drvdata(pdev, sp);
pdata = dev_get_platdata(&pdev->dev);
master->use_gpio_descriptors = true;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
master->setup = spi_bitbang_setup;
master->cleanup = spi_bitbang_cleanup;
if (pdata) {
master->bus_num = pdata->bus_num;
master->num_chipselect = pdata->num_chipselect;
}
sp->bitbang.master = master;
sp->bitbang.chipselect = ath79_spi_chipselect;
sp->bitbang.txrx_word[SPI_MODE_0] = ath79_spi_txrx_mode0;
sp->bitbang.flags = SPI_CS_HIGH;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sp->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(sp->base)) {
ret = PTR_ERR(sp->base);
goto err_put_master;
}
sp->clk = devm_clk_get(&pdev->dev, "ahb");
if (IS_ERR(sp->clk)) {
ret = PTR_ERR(sp->clk);
goto err_put_master;
}
ret = clk_prepare_enable(sp->clk);
if (ret)
goto err_put_master;
rate = DIV_ROUND_UP(clk_get_rate(sp->clk), MHZ);
if (!rate) {
ret = -EINVAL;
goto err_clk_disable;
}
sp->rrw_delay = ATH79_SPI_RRW_DELAY_FACTOR / rate;
dev_dbg(&pdev->dev, "register read/write delay is %u nsecs\n",
sp->rrw_delay);
ath79_spi_enable(sp);
ret = spi_bitbang_start(&sp->bitbang);
if (ret)
goto err_disable;
return 0;
err_disable:
ath79_spi_disable(sp);
err_clk_disable:
clk_disable_unprepare(sp->clk);
err_put_master:
spi_master_put(sp->bitbang.master);
return ret;
}
static int ath79_spi_remove(struct platform_device *pdev)
{
struct ath79_spi *sp = platform_get_drvdata(pdev);
spi_bitbang_stop(&sp->bitbang);
ath79_spi_disable(sp);
clk_disable_unprepare(sp->clk);
spi_master_put(sp->bitbang.master);
return 0;
}
static void ath79_spi_shutdown(struct platform_device *pdev)
{
ath79_spi_remove(pdev);
}
static const struct of_device_id ath79_spi_of_match[] = {
{ .compatible = "qca,ar7100-spi", },
{ },
};
MODULE_DEVICE_TABLE(of, ath79_spi_of_match);
static struct platform_driver ath79_spi_driver = {
.probe = ath79_spi_probe,
.remove = ath79_spi_remove,
.shutdown = ath79_spi_shutdown,
.driver = {
.name = DRV_NAME,
.of_match_table = ath79_spi_of_match,
},
};
module_platform_driver(ath79_spi_driver);
MODULE_DESCRIPTION("SPI controller driver for Atheros AR71XX/AR724X/AR913X");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRV_NAME);