linux/drivers/spi/spi-cavium.c
Amit Kumar Mahapatra via Alsa-devel 9e264f3f85
spi: Replace all spi->chip_select and spi->cs_gpiod references with function call
Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-03-11 12:34:01 +00:00

151 lines
3.5 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2011, 2012 Cavium, Inc.
*/
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/io.h>
#include "spi-cavium.h"
static void octeon_spi_wait_ready(struct octeon_spi *p)
{
union cvmx_mpi_sts mpi_sts;
unsigned int loops = 0;
do {
if (loops++)
__delay(500);
mpi_sts.u64 = readq(p->register_base + OCTEON_SPI_STS(p));
} while (mpi_sts.s.busy);
}
static int octeon_spi_do_transfer(struct octeon_spi *p,
struct spi_message *msg,
struct spi_transfer *xfer,
bool last_xfer)
{
struct spi_device *spi = msg->spi;
union cvmx_mpi_cfg mpi_cfg;
union cvmx_mpi_tx mpi_tx;
unsigned int clkdiv;
int mode;
bool cpha, cpol;
const u8 *tx_buf;
u8 *rx_buf;
int len;
int i;
mode = spi->mode;
cpha = mode & SPI_CPHA;
cpol = mode & SPI_CPOL;
clkdiv = p->sys_freq / (2 * xfer->speed_hz);
mpi_cfg.u64 = 0;
mpi_cfg.s.clkdiv = clkdiv;
mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0;
mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0;
mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0;
mpi_cfg.s.idlelo = cpha != cpol;
mpi_cfg.s.cslate = cpha ? 1 : 0;
mpi_cfg.s.enable = 1;
if (spi_get_chipselect(spi, 0) < 4)
p->cs_enax |= 1ull << (12 + spi_get_chipselect(spi, 0));
mpi_cfg.u64 |= p->cs_enax;
if (mpi_cfg.u64 != p->last_cfg) {
p->last_cfg = mpi_cfg.u64;
writeq(mpi_cfg.u64, p->register_base + OCTEON_SPI_CFG(p));
}
tx_buf = xfer->tx_buf;
rx_buf = xfer->rx_buf;
len = xfer->len;
while (len > OCTEON_SPI_MAX_BYTES) {
for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
u8 d;
if (tx_buf)
d = *tx_buf++;
else
d = 0;
writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
}
mpi_tx.u64 = 0;
mpi_tx.s.csid = spi_get_chipselect(spi, 0);
mpi_tx.s.leavecs = 1;
mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0;
mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES;
writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p));
octeon_spi_wait_ready(p);
if (rx_buf)
for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) {
u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
*rx_buf++ = (u8)v;
}
len -= OCTEON_SPI_MAX_BYTES;
}
for (i = 0; i < len; i++) {
u8 d;
if (tx_buf)
d = *tx_buf++;
else
d = 0;
writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
}
mpi_tx.u64 = 0;
mpi_tx.s.csid = spi_get_chipselect(spi, 0);
if (last_xfer)
mpi_tx.s.leavecs = xfer->cs_change;
else
mpi_tx.s.leavecs = !xfer->cs_change;
mpi_tx.s.txnum = tx_buf ? len : 0;
mpi_tx.s.totnum = len;
writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p));
octeon_spi_wait_ready(p);
if (rx_buf)
for (i = 0; i < len; i++) {
u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i));
*rx_buf++ = (u8)v;
}
spi_transfer_delay_exec(xfer);
return xfer->len;
}
int octeon_spi_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
struct octeon_spi *p = spi_master_get_devdata(master);
unsigned int total_len = 0;
int status = 0;
struct spi_transfer *xfer;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
bool last_xfer = list_is_last(&xfer->transfer_list,
&msg->transfers);
int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer);
if (r < 0) {
status = r;
goto err;
}
total_len += r;
}
err:
msg->status = status;
msg->actual_length = total_len;
spi_finalize_current_message(master);
return status;
}