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FMC DEL 1ns 4cha - Software
Commit f523e511 authored by Tomasz Wlostowski's avatar Tomasz Wlostowski Committed by Alessandro Rubini
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gpio.c: write with retries (workaround for possible SPI arbitration issues)

parent 75e4ee4b
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Showing with 35 additions and 22 deletions
fine-delay.h
View file @ f523e511
......@@ -150,7 +150,9 @@ struct spec_fd {
int temp; /* temperature: scaled by 4 bits */
int verbose;
uint32_t tdc_attrs[FD_ATTR_TDC__LAST - FD_ATTR_DEV__LAST];
uint16_t mcp_iodir, mcp_olat;
};
/* We act on flags using atomic ops, so flag is the number, not the mask */
enum fd_flags {
FD_FLAG_INITED = 0,
......
gpio.c
View file @ f523e511
......@@ -14,6 +14,8 @@
#include <linux/io.h>
#include "fine-delay.h"
#define SPI_RETRIES 100
static int gpio_writel(struct spec_fd *fd, int val, int reg)
{
return fd_spi_xfer(fd, FD_CS_GPIO, 24,
......@@ -32,35 +34,41 @@ static int gpio_readl(struct spec_fd *fd, int reg)
return ret & 0xff;
}
void fd_gpio_dir(struct spec_fd *fd, int mask, int dir)
static int gpio_writel_with_retry(struct spec_fd *fd, int val, int reg)
{
int addr, val;
int retries = SPI_RETRIES, rv;
while(retries--)
{
gpio_writel(fd, val, reg);
rv = gpio_readl(fd, reg);
if(rv >= 0 && (rv == val))
{
if(SPI_RETRIES-1-retries > 0)
printk("gpio_writel_with_retry: succeded after %d retries\n", SPI_RETRIES-1-retries);
return 0;
}
}
return -EIO;
}
/* if mask is bits 8..15 use the next address */
addr = FD_MCP_IODIR;
if (mask & 0xff00) {
mask >>= 8;
addr++;
}
val = gpio_readl(fd, addr) & ~mask;
void fd_gpio_dir(struct spec_fd *fd, int mask, int dir)
{
fd->mcp_iodir &= ~mask;
if (dir == FD_GPIO_IN)
val |= mask;
gpio_writel(fd, val, addr);
fd->mcp_iodir |= mask;
gpio_writel_with_retry(fd, (fd->mcp_iodir & 0xff), FD_MCP_IODIR);
gpio_writel_with_retry(fd, (fd->mcp_iodir >> 8), FD_MCP_IODIR+1);
}
void fd_gpio_val(struct spec_fd *fd, int mask, int values)
{
int addr, reg;
/* if mask is bits 8..15 use the next address */
addr = FD_MCP_OLAT;
if (mask & 0xff00) {
mask >>= 8;
values >>= 8;
addr++;
}
reg = gpio_readl(fd, addr) & ~mask;
gpio_writel(fd, reg | values, addr);
fd->mcp_olat &= ~mask;
fd->mcp_olat |= values;
gpio_writel_with_retry(fd, (fd->mcp_olat & 0xff), FD_MCP_OLAT);
gpio_writel_with_retry(fd, (fd->mcp_olat >> 8), FD_MCP_OLAT+1);
}
void fd_gpio_set_clr(struct spec_fd *fd, int mask, int set)
......@@ -75,6 +83,9 @@ int fd_gpio_init(struct spec_fd *fd)
{
int i, val;
fd->mcp_iodir = 0xffff;
fd->mcp_olat = 0;
pr_debug("%s\n",__func__);
if (gpio_writel(fd, 0x00, FD_MCP_IOCON) < 0)
goto out;
......
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