freebsd-dev/sys/arm/xilinx/zy7_spi.c

596 lines
16 KiB
C

/*-
* Copyright (c) 2018 Thomas Skibo <thomasskibo@yahoo.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/uio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/stdarg.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include "spibus_if.h"
static struct ofw_compat_data compat_data[] = {
{"xlnx,zy7_spi", 1},
{"xlnx,zynq-spi-1.0", 1},
{"cdns,spi-r1p6", 1},
{NULL, 0}
};
struct zy7_spi_softc {
device_t dev;
device_t child;
struct mtx sc_mtx;
struct resource *mem_res;
struct resource *irq_res;
void *intrhandle;
uint32_t cfg_reg_shadow;
uint32_t spi_clock;
uint32_t ref_clock;
unsigned int spi_clk_real_freq;
unsigned int rx_overflows;
unsigned int tx_underflows;
unsigned int interrupts;
unsigned int stray_ints;
struct spi_command *cmd;
int tx_bytes; /* tx_cmd_sz + tx_data_sz */
int tx_bytes_sent;
int rx_bytes; /* rx_cmd_sz + rx_data_sz */
int rx_bytes_rcvd;
int busy;
};
#define ZY7_SPI_DEFAULT_SPI_CLOCK 50000000
#define SPI_SC_LOCK(sc) mtx_lock(&(sc)->sc_mtx)
#define SPI_SC_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx)
#define SPI_SC_LOCK_INIT(sc) \
mtx_init(&(sc)->sc_mtx, device_get_nameunit((sc)->dev), NULL, MTX_DEF)
#define SPI_SC_LOCK_DESTROY(sc) mtx_destroy(&(sc)->sc_mtx)
#define SPI_SC_ASSERT_LOCKED(sc) mtx_assert(&(sc)->sc_mtx, MA_OWNED)
#define RD4(sc, off) (bus_read_4((sc)->mem_res, (off)))
#define WR4(sc, off, val) (bus_write_4((sc)->mem_res, (off), (val)))
/*
* SPI device registers.
* Reference: Zynq-7000 All Programmable SoC Technical Reference Manual.
* (v1.12.1) December 6, 2017. Xilinx doc UG585.
*/
#define ZY7_SPI_CONFIG_REG 0x0000
#define ZY7_SPI_CONFIG_MODEFAIL_GEN_EN (1 << 17)
#define ZY7_SPI_CONFIG_MAN_STRT (1 << 16)
#define ZY7_SPI_CONFIG_MAN_STRT_EN (1 << 15)
#define ZY7_SPI_CONFIG_MAN_CS (1 << 14)
#define ZY7_SPI_CONFIG_CS_MASK (0xf << 10)
#define ZY7_SPI_CONFIG_CS(x) ((0xf ^ (1 << (x))) << 10)
#define ZY7_SPI_CONFIG_PERI_SEL (1 << 9)
#define ZY7_SPI_CONFIG_REF_CLK (1 << 8)
#define ZY7_SPI_CONFIG_BAUD_RATE_DIV_MASK (7 << 3)
#define ZY7_SPI_CONFIG_BAUD_RATE_DIV_SHIFT 3
#define ZY7_SPI_CONFIG_BAUD_RATE_DIV(x) ((x) << 3) /* divide by 2<<x */
#define ZY7_SPI_CONFIG_CLK_PH (1 << 2) /* clock phase */
#define ZY7_SPI_CONFIG_CLK_POL (1 << 1) /* clock polatiry */
#define ZY7_SPI_CONFIG_MODE_SEL (1 << 0) /* master enable */
#define ZY7_SPI_INTR_STAT_REG 0x0004
#define ZY7_SPI_INTR_EN_REG 0x0008
#define ZY7_SPI_INTR_DIS_REG 0x000c
#define ZY7_SPI_INTR_MASK_REG 0x0010
#define ZY7_SPI_INTR_TX_FIFO_UNDERFLOW (1 << 6)
#define ZY7_SPI_INTR_RX_FIFO_FULL (1 << 5)
#define ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY (1 << 4)
#define ZY7_SPI_INTR_TX_FIFO_FULL (1 << 3)
#define ZY7_SPI_INTR_TX_FIFO_NOT_FULL (1 << 2)
#define ZY7_SPI_INTR_MODE_FAULT (1 << 1)
#define ZY7_SPI_INTR_RX_OVERFLOW (1 << 0)
#define ZY7_SPI_EN_REG 0x0014
#define ZY7_SPI_ENABLE (1 << 0)
#define ZY7_SPI_DELAY_CTRL_REG 0x0018
#define ZY7_SPI_DELAY_CTRL_BTWN_MASK (0xff << 16)
#define ZY7_SPI_DELAY_CTRL_BTWN_SHIFT 16
#define ZY7_SPI_DELAY_CTRL_AFTER_MASK (0xff << 8)
#define ZY7_SPI_DELAY_CTRL_AFTER_SHIFT 8
#define ZY7_SPI_DELAY_CTRL_INIT_MASK (0xff << 0)
#define ZY7_SPI_DELAY_CTRL_INIT_SHIFT 0
#define ZY7_SPI_TX_DATA_REG 0x001c
#define ZY7_SPI_RX_DATA_REG 0x0020
#define ZY7_SPI_SLV_IDLE_COUNT_REG 0x0024
#define ZY7_SPI_TX_THRESH_REG 0x0028
#define ZY7_SPI_RX_THRESH_REG 0x002c
/* Fill hardware fifo with command and data bytes. */
static void
zy7_spi_write_fifo(struct zy7_spi_softc *sc, int nbytes)
{
uint8_t byte;
while (nbytes > 0) {
if (sc->tx_bytes_sent < sc->cmd->tx_cmd_sz)
/* Writing command. */
byte = *((uint8_t *)sc->cmd->tx_cmd +
sc->tx_bytes_sent);
else
/* Writing data. */
byte = *((uint8_t *)sc->cmd->tx_data +
(sc->tx_bytes_sent - sc->cmd->tx_cmd_sz));
WR4(sc, ZY7_SPI_TX_DATA_REG, (uint32_t)byte);
sc->tx_bytes_sent++;
nbytes--;
}
}
/* Read hardware fifo data into command response and data buffers. */
static void
zy7_spi_read_fifo(struct zy7_spi_softc *sc)
{
uint8_t byte;
do {
byte = RD4(sc, ZY7_SPI_RX_DATA_REG) & 0xff;
if (sc->rx_bytes_rcvd < sc->cmd->rx_cmd_sz)
/* Reading command. */
*((uint8_t *)sc->cmd->rx_cmd + sc->rx_bytes_rcvd) =
byte;
else
/* Reading data. */
*((uint8_t *)sc->cmd->rx_data +
(sc->rx_bytes_rcvd - sc->cmd->rx_cmd_sz)) =
byte;
sc->rx_bytes_rcvd++;
} while (sc->rx_bytes_rcvd < sc->rx_bytes &&
(RD4(sc, ZY7_SPI_INTR_STAT_REG) &
ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY) != 0);
}
/* End a transfer early by draining rx fifo and disabling interrupts. */
static void
zy7_spi_abort_transfer(struct zy7_spi_softc *sc)
{
/* Drain receive fifo. */
while ((RD4(sc, ZY7_SPI_INTR_STAT_REG) &
ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY) != 0)
(void)RD4(sc, ZY7_SPI_RX_DATA_REG);
/* Shut down interrupts. */
WR4(sc, ZY7_SPI_INTR_DIS_REG,
ZY7_SPI_INTR_RX_OVERFLOW |
ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY |
ZY7_SPI_INTR_TX_FIFO_NOT_FULL);
}
static void
zy7_spi_intr(void *arg)
{
struct zy7_spi_softc *sc = (struct zy7_spi_softc *)arg;
uint32_t istatus;
SPI_SC_LOCK(sc);
sc->interrupts++;
istatus = RD4(sc, ZY7_SPI_INTR_STAT_REG);
/* Stray interrupts can happen if a transfer gets interrupted. */
if (!sc->busy) {
sc->stray_ints++;
SPI_SC_UNLOCK(sc);
return;
}
if ((istatus & ZY7_SPI_INTR_RX_OVERFLOW) != 0) {
device_printf(sc->dev, "rx fifo overflow!\n");
sc->rx_overflows++;
/* Clear status bit. */
WR4(sc, ZY7_SPI_INTR_STAT_REG,
ZY7_SPI_INTR_RX_OVERFLOW);
}
/* Empty receive fifo before any more transmit data is sent. */
if (sc->rx_bytes_rcvd < sc->rx_bytes &&
(istatus & ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY) != 0) {
zy7_spi_read_fifo(sc);
if (sc->rx_bytes_rcvd == sc->rx_bytes)
/* Disable receive interrupts. */
WR4(sc, ZY7_SPI_INTR_DIS_REG,
ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY |
ZY7_SPI_INTR_RX_OVERFLOW);
}
/* Count tx underflows. They probably shouldn't happen. */
if ((istatus & ZY7_SPI_INTR_TX_FIFO_UNDERFLOW) != 0) {
sc->tx_underflows++;
/* Clear status bit. */
WR4(sc, ZY7_SPI_INTR_STAT_REG,
ZY7_SPI_INTR_TX_FIFO_UNDERFLOW);
}
/* Fill transmit fifo. */
if (sc->tx_bytes_sent < sc->tx_bytes &&
(istatus & ZY7_SPI_INTR_TX_FIFO_NOT_FULL) != 0) {
zy7_spi_write_fifo(sc, MIN(96, sc->tx_bytes -
sc->tx_bytes_sent));
if (sc->tx_bytes_sent == sc->tx_bytes) {
/* Disable transmit FIFO interrupt, enable receive
* FIFO interrupt.
*/
WR4(sc, ZY7_SPI_INTR_DIS_REG,
ZY7_SPI_INTR_TX_FIFO_NOT_FULL);
WR4(sc, ZY7_SPI_INTR_EN_REG,
ZY7_SPI_INTR_RX_FIFO_NOT_EMPTY);
}
}
/* Finished with transfer? */
if (sc->tx_bytes_sent == sc->tx_bytes &&
sc->rx_bytes_rcvd == sc->rx_bytes) {
/* De-assert CS. */
sc->cfg_reg_shadow &=
~(ZY7_SPI_CONFIG_CLK_PH | ZY7_SPI_CONFIG_CLK_POL);
sc->cfg_reg_shadow |= ZY7_SPI_CONFIG_CS_MASK;
WR4(sc, ZY7_SPI_CONFIG_REG, sc->cfg_reg_shadow);
wakeup(sc->dev);
}
SPI_SC_UNLOCK(sc);
}
/* Initialize hardware. */
static int
zy7_spi_init_hw(struct zy7_spi_softc *sc)
{
uint32_t baud_div;
/* Find best clock divider. Divide by 2 not supported. */
baud_div = 1;
while ((sc->ref_clock >> (baud_div + 1)) > sc->spi_clock &&
baud_div < 8)
baud_div++;
if (baud_div >= 8) {
device_printf(sc->dev, "cannot configure clock divider: ref=%d"
" spi=%d.\n", sc->ref_clock, sc->spi_clock);
return (EINVAL);
}
sc->spi_clk_real_freq = sc->ref_clock >> (baud_div + 1);
/* Set up configuration register. */
sc->cfg_reg_shadow =
ZY7_SPI_CONFIG_MAN_CS |
ZY7_SPI_CONFIG_CS_MASK |
ZY7_SPI_CONFIG_BAUD_RATE_DIV(baud_div) |
ZY7_SPI_CONFIG_MODE_SEL;
WR4(sc, ZY7_SPI_CONFIG_REG, sc->cfg_reg_shadow);
/* Set thresholds. */
WR4(sc, ZY7_SPI_TX_THRESH_REG, 32);
WR4(sc, ZY7_SPI_RX_THRESH_REG, 1);
/* Clear and disable all interrupts. */
WR4(sc, ZY7_SPI_INTR_STAT_REG, ~0);
WR4(sc, ZY7_SPI_INTR_DIS_REG, ~0);
/* Enable SPI. */
WR4(sc, ZY7_SPI_EN_REG, ZY7_SPI_ENABLE);
return (0);
}
static void
zy7_spi_add_sysctls(device_t dev)
{
struct zy7_spi_softc *sc = device_get_softc(dev);
struct sysctl_ctx_list *ctx;
struct sysctl_oid_list *child;
ctx = device_get_sysctl_ctx(dev);
child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "spi_clk_real_freq", CTLFLAG_RD,
&sc->spi_clk_real_freq, 0, "SPI clock real frequency");
SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "rx_overflows", CTLFLAG_RD,
&sc->rx_overflows, 0, "RX FIFO overflow events");
SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "tx_underflows", CTLFLAG_RD,
&sc->tx_underflows, 0, "TX FIFO underflow events");
SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "interrupts", CTLFLAG_RD,
&sc->interrupts, 0, "interrupt calls");
SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "stray_ints", CTLFLAG_RD,
&sc->stray_ints, 0, "stray interrupts");
}
static int
zy7_spi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
return (ENXIO);
device_set_desc(dev, "Zynq SPI Controller");
return (BUS_PROBE_DEFAULT);
}
static int zy7_spi_detach(device_t);
static int
zy7_spi_attach(device_t dev)
{
struct zy7_spi_softc *sc;
int rid, err;
phandle_t node;
pcell_t cell;
sc = device_get_softc(dev);
sc->dev = dev;
SPI_SC_LOCK_INIT(sc);
/* Get ref-clock and spi-clock properties. */
node = ofw_bus_get_node(dev);
if (OF_getprop(node, "ref-clock", &cell, sizeof(cell)) > 0)
sc->ref_clock = fdt32_to_cpu(cell);
else {
device_printf(dev, "must have ref-clock property\n");
return (ENXIO);
}
if (OF_getprop(node, "spi-clock", &cell, sizeof(cell)) > 0)
sc->spi_clock = fdt32_to_cpu(cell);
else
sc->spi_clock = ZY7_SPI_DEFAULT_SPI_CLOCK;
/* Get memory resource. */
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (sc->mem_res == NULL) {
device_printf(dev, "could not allocate memory resources.\n");
zy7_spi_detach(dev);
return (ENOMEM);
}
/* Allocate IRQ. */
rid = 0;
sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
if (sc->irq_res == NULL) {
device_printf(dev, "could not allocate IRQ resource.\n");
zy7_spi_detach(dev);
return (ENOMEM);
}
/* Activate the interrupt. */
err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
NULL, zy7_spi_intr, sc, &sc->intrhandle);
if (err) {
device_printf(dev, "could not setup IRQ.\n");
zy7_spi_detach(dev);
return (err);
}
/* Configure the device. */
err = zy7_spi_init_hw(sc);
if (err) {
zy7_spi_detach(dev);
return (err);
}
sc->child = device_add_child(dev, "spibus", -1);
zy7_spi_add_sysctls(dev);
/* Attach spibus driver as a child later when interrupts work. */
config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev);
return (0);
}
static int
zy7_spi_detach(device_t dev)
{
struct zy7_spi_softc *sc = device_get_softc(dev);
if (device_is_attached(dev))
bus_generic_detach(dev);
/* Delete child bus. */
if (sc->child)
device_delete_child(dev, sc->child);
/* Disable hardware. */
if (sc->mem_res != NULL) {
/* Disable SPI. */
WR4(sc, ZY7_SPI_EN_REG, 0);
/* Clear and disable all interrupts. */
WR4(sc, ZY7_SPI_INTR_STAT_REG, ~0);
WR4(sc, ZY7_SPI_INTR_DIS_REG, ~0);
}
/* Teardown and release interrupt. */
if (sc->irq_res != NULL) {
if (sc->intrhandle)
bus_teardown_intr(dev, sc->irq_res, sc->intrhandle);
bus_release_resource(dev, SYS_RES_IRQ,
rman_get_rid(sc->irq_res), sc->irq_res);
}
/* Release memory resource. */
if (sc->mem_res != NULL)
bus_release_resource(dev, SYS_RES_MEMORY,
rman_get_rid(sc->mem_res), sc->mem_res);
SPI_SC_LOCK_DESTROY(sc);
return (0);
}
static phandle_t
zy7_spi_get_node(device_t bus, device_t dev)
{
return (ofw_bus_get_node(bus));
}
static int
zy7_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct zy7_spi_softc *sc = device_get_softc(dev);
uint32_t cs;
uint32_t mode;
int err = 0;
KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
("TX/RX command sizes should be equal"));
KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
("TX/RX data sizes should be equal"));
/* Get chip select and mode for this child. */
spibus_get_cs(child, &cs);
cs &= ~SPIBUS_CS_HIGH;
if (cs > 2) {
device_printf(dev, "Invalid chip select %d requested by %s",
cs, device_get_nameunit(child));
return (EINVAL);
}
spibus_get_mode(child, &mode);
SPI_SC_LOCK(sc);
/* Wait for controller available. */
while (sc->busy != 0) {
err = mtx_sleep(dev, &sc->sc_mtx, 0, "zspi0", 0);
if (err) {
SPI_SC_UNLOCK(sc);
return (err);
}
}
/* Start transfer. */
sc->busy = 1;
sc->cmd = cmd;
sc->tx_bytes = sc->cmd->tx_cmd_sz + sc->cmd->tx_data_sz;
sc->tx_bytes_sent = 0;
sc->rx_bytes = sc->cmd->rx_cmd_sz + sc->cmd->rx_data_sz;
sc->rx_bytes_rcvd = 0;
/* Enable interrupts. zy7_spi_intr() will handle transfer. */
WR4(sc, ZY7_SPI_INTR_EN_REG,
ZY7_SPI_INTR_TX_FIFO_NOT_FULL |
ZY7_SPI_INTR_RX_OVERFLOW);
/* Handle polarity and phase. */
if (mode == SPIBUS_MODE_CPHA || mode == SPIBUS_MODE_CPOL_CPHA)
sc->cfg_reg_shadow |= ZY7_SPI_CONFIG_CLK_PH;
if (mode == SPIBUS_MODE_CPOL || mode == SPIBUS_MODE_CPOL_CPHA)
sc->cfg_reg_shadow |= ZY7_SPI_CONFIG_CLK_POL;
/* Assert CS. */
sc->cfg_reg_shadow &= ~ZY7_SPI_CONFIG_CS_MASK;
sc->cfg_reg_shadow |= ZY7_SPI_CONFIG_CS(cs);
WR4(sc, ZY7_SPI_CONFIG_REG, sc->cfg_reg_shadow);
/* Wait for completion. */
err = mtx_sleep(dev, &sc->sc_mtx, 0, "zspi1", hz * 2);
if (err)
zy7_spi_abort_transfer(sc);
/* Release controller. */
sc->busy = 0;
wakeup_one(dev);
SPI_SC_UNLOCK(sc);
return (err);
}
static device_method_t zy7_spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, zy7_spi_probe),
DEVMETHOD(device_attach, zy7_spi_attach),
DEVMETHOD(device_detach, zy7_spi_detach),
/* SPI interface */
DEVMETHOD(spibus_transfer, zy7_spi_transfer),
/* ofw_bus interface */
DEVMETHOD(ofw_bus_get_node, zy7_spi_get_node),
DEVMETHOD_END
};
static driver_t zy7_spi_driver = {
"zy7_spi",
zy7_spi_methods,
sizeof(struct zy7_spi_softc),
};
DRIVER_MODULE(zy7_spi, simplebus, zy7_spi_driver, 0, 0);
DRIVER_MODULE(ofw_spibus, zy7_spi, ofw_spibus_driver, 0, 0);
SIMPLEBUS_PNP_INFO(compat_data);
MODULE_DEPEND(zy7_spi, ofw_spibus, 1, 1, 1);