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linux-stable/drivers/spi/spi-oc-tiny.c
Alexander A. Klimov 3ea4eac3e2
SPI SUBSYSTEM: Replace HTTP links with HTTPS ones 
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200708194400.22213-1-grandmaster@al2klimov.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-07-09 22:41:11 +01:00

306 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* OpenCores tiny SPI master driver
*
* https://opencores.org/project,tiny_spi
*
* Copyright (C) 2011 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/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/spi/spi_oc_tiny.h>
#include <linux/io.h>
#include <linux/of.h>
#define DRV_NAME "spi_oc_tiny"
#define TINY_SPI_RXDATA 0
#define TINY_SPI_TXDATA 4
#define TINY_SPI_STATUS 8
#define TINY_SPI_CONTROL 12
#define TINY_SPI_BAUD 16
#define TINY_SPI_STATUS_TXE 0x1
#define TINY_SPI_STATUS_TXR 0x2
struct tiny_spi {
/* bitbang has to be first */
struct spi_bitbang bitbang;
struct completion done;
void __iomem *base;
int irq;
unsigned int freq;
unsigned int baudwidth;
unsigned int baud;
unsigned int speed_hz;
unsigned int mode;
unsigned int len;
unsigned int txc, rxc;
const u8 *txp;
u8 *rxp;
};
static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
{
return spi_master_get_devdata(sdev->master);
}
static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
}
static int tiny_spi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
unsigned int baud = hw->baud;
if (t) {
if (t->speed_hz && t->speed_hz != hw->speed_hz)
baud = tiny_spi_baud(spi, t->speed_hz);
}
writel(baud, hw->base + TINY_SPI_BAUD);
writel(hw->mode, hw->base + TINY_SPI_CONTROL);
return 0;
}
static int tiny_spi_setup(struct spi_device *spi)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
if (spi->max_speed_hz != hw->speed_hz) {
hw->speed_hz = spi->max_speed_hz;
hw->baud = tiny_spi_baud(spi, hw->speed_hz);
}
hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
return 0;
}
static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
{
while (!(readb(hw->base + TINY_SPI_STATUS) &
TINY_SPI_STATUS_TXR))
cpu_relax();
}
static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
{
while (!(readb(hw->base + TINY_SPI_STATUS) &
TINY_SPI_STATUS_TXE))
cpu_relax();
}
static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct tiny_spi *hw = tiny_spi_to_hw(spi);
const u8 *txp = t->tx_buf;
u8 *rxp = t->rx_buf;
unsigned int i;
if (hw->irq >= 0) {
/* use interrupt driven data transfer */
hw->len = t->len;
hw->txp = t->tx_buf;
hw->rxp = t->rx_buf;
hw->txc = 0;
hw->rxc = 0;
/* send the first byte */
if (t->len > 1) {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
} else {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
}
wait_for_completion(&hw->done);
} else {
/* we need to tighten the transfer loop */
writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
for (i = 1; i < t->len; i++) {
writeb(txp ? *txp++ : 0, hw->base + TINY_SPI_TXDATA);
if (rxp || (i != t->len - 1))
tiny_spi_wait_txr(hw);
if (rxp)
*rxp++ = readb(hw->base + TINY_SPI_TXDATA);
}
tiny_spi_wait_txe(hw);
if (rxp)
*rxp++ = readb(hw->base + TINY_SPI_RXDATA);
}
return t->len;
}
static irqreturn_t tiny_spi_irq(int irq, void *dev)
{
struct tiny_spi *hw = dev;
writeb(0, hw->base + TINY_SPI_STATUS);
if (hw->rxc + 1 == hw->len) {
if (hw->rxp)
*hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
hw->rxc++;
complete(&hw->done);
} else {
if (hw->rxp)
*hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
hw->rxc++;
if (hw->txc < hw->len) {
writeb(hw->txp ? *hw->txp++ : 0,
hw->base + TINY_SPI_TXDATA);
hw->txc++;
writeb(TINY_SPI_STATUS_TXR,
hw->base + TINY_SPI_STATUS);
} else {
writeb(TINY_SPI_STATUS_TXE,
hw->base + TINY_SPI_STATUS);
}
}
return IRQ_HANDLED;
}
#ifdef CONFIG_OF
#include <linux/of_gpio.h>
static int tiny_spi_of_probe(struct platform_device *pdev)
{
struct tiny_spi *hw = platform_get_drvdata(pdev);
struct device_node *np = pdev->dev.of_node;
u32 val;
if (!np)
return 0;
hw->bitbang.master->dev.of_node = pdev->dev.of_node;
if (!of_property_read_u32(np, "clock-frequency", &val))
hw->freq = val;
if (!of_property_read_u32(np, "baud-width", &val))
hw->baudwidth = val;
return 0;
}
#else /* !CONFIG_OF */
static int tiny_spi_of_probe(struct platform_device *pdev)
{
return 0;
}
#endif /* CONFIG_OF */
static int tiny_spi_probe(struct platform_device *pdev)
{
struct tiny_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
struct tiny_spi *hw;
struct spi_master *master;
int err = -ENODEV;
master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
if (!master)
return err;
/* setup the master state. */
master->bus_num = pdev->id;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->setup = tiny_spi_setup;
master->use_gpio_descriptors = true;
hw = spi_master_get_devdata(master);
platform_set_drvdata(pdev, hw);
/* setup the state for the bitbang driver */
hw->bitbang.master = master;
hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
/* 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;
}
/* irq is optional */
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq >= 0) {
init_completion(&hw->done);
err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
pdev->name, hw);
if (err)
goto exit;
}
/* find platform data */
if (platp) {
hw->freq = platp->freq;
hw->baudwidth = platp->baudwidth;
} else {
err = tiny_spi_of_probe(pdev);
if (err)
goto exit;
}
/* register our spi controller */
err = spi_bitbang_start(&hw->bitbang);
if (err)
goto exit;
dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
return 0;
exit:
spi_master_put(master);
return err;
}
static int tiny_spi_remove(struct platform_device *pdev)
{
struct tiny_spi *hw = platform_get_drvdata(pdev);
struct spi_master *master = hw->bitbang.master;
spi_bitbang_stop(&hw->bitbang);
spi_master_put(master);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id tiny_spi_match[] = {
{ .compatible = "opencores,tiny-spi-rtlsvn2", },
{},
};
MODULE_DEVICE_TABLE(of, tiny_spi_match);
#endif /* CONFIG_OF */
static struct platform_driver tiny_spi_driver = {
.probe = tiny_spi_probe,
.remove = tiny_spi_remove,
.driver = {
.name = DRV_NAME,
.pm = NULL,
.of_match_table = of_match_ptr(tiny_spi_match),
},
};
module_platform_driver(tiny_spi_driver);
MODULE_DESCRIPTION("OpenCores tiny SPI driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
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