u-boot/board/gdsys/common/mclink.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2012
* Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
*/
#ifdef CONFIG_GDSYS_LEGACY_DRIVERS
#include <common.h>
#include <asm/io.h>
#include <errno.h>
#include <gdsys_fpga.h>
#include <linux/delay.h>
enum {
MCINT_SLAVE_LINK_CHANGED_EV = 1 << 7,
MCINT_TX_ERROR_EV = 1 << 9,
MCINT_TX_BUFFER_FREE = 1 << 10,
MCINT_TX_PACKET_TRANSMITTED_EV = 1 << 11,
MCINT_RX_ERROR_EV = 1 << 13,
MCINT_RX_CONTENT_AVAILABLE = 1 << 14,
MCINT_RX_PACKET_RECEIVED_EV = 1 << 15,
};
int mclink_probe(void)
{
unsigned int k;
int slaves = 0;
for (k = 0; k < CONFIG_SYS_MCLINK_MAX; ++k) {
int timeout = 0;
unsigned int ctr = 0;
u16 mc_status;
FPGA_GET_REG(k, mc_status, &mc_status);
if (!(mc_status & (1 << 15)))
break;
FPGA_SET_REG(k, mc_control, 0x8000);
FPGA_GET_REG(k, mc_status, &mc_status);
while (!(mc_status & (1 << 14))) {
udelay(100);
if (ctr++ > 500) {
timeout = 1;
break;
}
FPGA_GET_REG(k, mc_status, &mc_status);
}
if (timeout)
break;
printf("waited %d us for mclink %d to come up\n", ctr * 100, k);
slaves++;
}
return slaves;
}
int mclink_send(u8 slave, u16 addr, u16 data)
{
unsigned int ctr = 0;
u16 int_status;
u16 rx_cmd_status;
u16 rx_cmd;
/* reset interrupt status */
FPGA_GET_REG(0, mc_int, &int_status);
FPGA_SET_REG(0, mc_int, int_status);
/* send */
FPGA_SET_REG(0, mc_tx_address, addr);
FPGA_SET_REG(0, mc_tx_data, data);
FPGA_SET_REG(0, mc_tx_cmd, (slave & 0x03) << 14);
FPGA_SET_REG(0, mc_control, 0x8001);
/* wait for reply */
FPGA_GET_REG(0, mc_int, &int_status);
while (!(int_status & MCINT_RX_PACKET_RECEIVED_EV)) {
udelay(100);
if (ctr++ > 3)
return -ETIMEDOUT;
FPGA_GET_REG(0, mc_int, &int_status);
}
FPGA_GET_REG(0, mc_rx_cmd_status, &rx_cmd_status);
rx_cmd = (rx_cmd_status >> 12) & 0x03;
if (rx_cmd != 0)
printf("mclink_send: received cmd %d, expected %d\n", rx_cmd,
0);
return 0;
}
int mclink_receive(u8 slave, u16 addr, u16 *data)
{
u16 rx_cmd_status;
u16 rx_cmd;
u16 int_status;
unsigned int ctr = 0;
/* send read request */
FPGA_SET_REG(0, mc_tx_address, addr);
FPGA_SET_REG(0, mc_tx_cmd,
((slave & 0x03) << 14) | (1 << 12) | (1 << 0));
FPGA_SET_REG(0, mc_control, 0x8001);
/* wait for reply */
FPGA_GET_REG(0, mc_int, &int_status);
while (!(int_status & MCINT_RX_CONTENT_AVAILABLE)) {
udelay(100);
if (ctr++ > 3)
return -ETIMEDOUT;
FPGA_GET_REG(0, mc_int, &int_status);
}
/* check reply */
FPGA_GET_REG(0, mc_rx_cmd_status, &rx_cmd_status);
if ((rx_cmd_status >> 14) != slave) {
printf("mclink_receive: reply from slave %d, expected %d\n",
rx_cmd_status >> 14, slave);
return -EINVAL;
}
rx_cmd = (rx_cmd_status >> 12) & 0x03;
if (rx_cmd != 1) {
printf("mclink_send: received cmd %d, expected %d\n",
rx_cmd, 1);
return -EIO;
}
FPGA_GET_REG(0, mc_rx_data, data);
return 0;
}
#endif /* CONFIG_GDSYS_LEGACY_DRIVERS */