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freebsd-dev/sys/powerpc/mpc85xx/fsl_espi.c

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/*-
* Copyright (c) 2017 Justin Hibbits <jhibbits@FreeBSD.org>
* 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <machine/bus.h>
#include <dev/spibus/spi.h>
#include <dev/spibus/spibusvar.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <powerpc/mpc85xx/mpc85xx.h>
#include "spibus_if.h"
/* TODO:
*
* Optimize FIFO reads and writes to do word-at-a-time instead of byte-at-a-time
*/
#define ESPI_SPMODE 0x0
#define ESPI_SPMODE_EN 0x80000000
#define ESPI_SPMODE_LOOP 0x40000000
#define ESPI_SPMODE_HO_ADJ_M 0x00070000
#define ESPI_SPMODE_TXTHR_M 0x00003f00
#define ESPI_SPMODE_TXTHR_S 8
#define ESPI_SPMODE_RXTHR_M 0x0000001f
#define ESPI_SPMODE_RXTHR_S 0
#define ESPI_SPIE 0x4
#define ESPI_SPIE_RXCNT_M 0x3f000000
#define ESPI_SPIE_RXCNT_S 24
#define ESPI_SPIE_TXCNT_M 0x003f0000
#define ESPI_SPIE_TXCNT_S 16
#define ESPI_SPIE_TXE 0x00008000
#define ESPI_SPIE_DON 0x00004000
#define ESPI_SPIE_RXT 0x00002000
#define ESPI_SPIE_RXF 0x00001000
#define ESPI_SPIE_TXT 0x00000800
#define ESPI_SPIE_RNE 0x00000200
#define ESPI_SPIE_TNF 0x00000100
#define ESPI_SPIM 0x8
#define ESPI_SPCOM 0xc
#define ESPI_SPCOM_CS_M 0xc0000000
#define ESPI_SPCOM_CS_S 30
#define ESPI_SPCOM_RXDELAY 0x20000000
#define ESPI_SPCOM_DO 0x10000000
#define ESPI_SPCOM_TO 0x08000000
#define ESPI_SPCOM_HLD 0x04000000
#define ESPI_SPCOM_RXSKIP_M 0x00ff0000
#define ESPI_SPCOM_TRANLEN_M 0x0000ffff
#define ESPI_SPITF 0x10
#define ESPI_SPIRF 0x14
#define ESPI_SPMODE0 0x20
#define ESPI_SPMODE1 0x24
#define ESPI_SPMODE2 0x28
#define ESPI_SPMODE3 0x2c
#define ESPI_CSMODE_CI 0x80000000
#define ESPI_CSMODE_CP 0x40000000
#define ESPI_CSMODE_REV 0x20000000
#define ESPI_CSMODE_DIV16 0x10000000
#define ESPI_CSMODE_PM_M 0x0f000000
#define ESPI_CSMODE_PM_S 24
#define ESPI_CSMODE_ODD 0x00800000
#define ESPI_CSMODE_POL 0x00100000
#define ESPI_CSMODE_LEN_M 0x000f0000
#define ESPI_CSMODE_LEN(x) (x << 16)
#define ESPI_CSMODE_CSBEF_M 0x0000f000
#define ESPI_CSMODE_CSAFT_M 0x00000f00
#define ESPI_CSMODE_CSCG_M 0x000000f8
#define ESPI_CSMODE_CSCG(x) (x << 3)
#define ESPI_CSMODE(n) (ESPI_SPMODE0 + n * 4)
#define FSL_ESPI_WRITE(sc,off,val) bus_write_4(sc->sc_mem_res, off, val)
#define FSL_ESPI_READ(sc,off) bus_read_4(sc->sc_mem_res, off)
#define FSL_ESPI_WRITE_FIFO(sc,off,val) bus_write_1(sc->sc_mem_res, off, val)
#define FSL_ESPI_READ_FIFO(sc,off) bus_read_1(sc->sc_mem_res, off)
#define FSL_ESPI_LOCK(_sc) \
mtx_lock(&(_sc)->sc_mtx)
#define FSL_ESPI_UNLOCK(_sc) \
mtx_unlock(&(_sc)->sc_mtx)
struct fsl_espi_softc
{
device_t sc_dev;
struct resource *sc_mem_res;
struct resource *sc_irq_res;
struct mtx sc_mtx;
int sc_num_cs;
struct spi_command *sc_cmd;
uint32_t sc_len;
uint32_t sc_read;
uint32_t sc_flags;
#define FSL_ESPI_BUSY 0x00000001
uint32_t sc_written;
void * sc_intrhand;
};
static void fsl_espi_intr(void *);
static int
fsl_espi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "fsl,mpc8536-espi"))
return (ENXIO);
device_set_desc(dev, "Freescale eSPI controller");
return (BUS_PROBE_DEFAULT);
}
static int
fsl_espi_attach(device_t dev)
{
struct fsl_espi_softc *sc;
int rid;
phandle_t node;
sc = device_get_softc(dev);
sc->sc_dev = dev;
node = ofw_bus_get_node(dev);
rid = 0;
sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (!sc->sc_mem_res) {
device_printf(dev, "cannot allocate memory resource\n");
return (ENXIO);
}
rid = 0;
sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
if (!sc->sc_irq_res) {
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
device_printf(dev, "cannot allocate interrupt\n");
return (ENXIO);
}
/* Hook up our interrupt handler. */
if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
NULL, fsl_espi_intr, sc, &sc->sc_intrhand)) {
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
device_printf(dev, "cannot setup the interrupt handler\n");
return (ENXIO);
}
if (OF_getencprop(node, "fsl,espi-num-chipselects",
&sc->sc_num_cs, sizeof(sc->sc_num_cs)) < 0 )
sc->sc_num_cs = 4;
mtx_init(&sc->sc_mtx, "fsl_espi", NULL, MTX_DEF);
/* Enable the SPI controller. */
FSL_ESPI_WRITE(sc, ESPI_SPMODE, ESPI_SPMODE_EN |
(16 << ESPI_SPMODE_TXTHR_S) | (15 << ESPI_SPMODE_RXTHR_S));
/* Disable all interrupts until we start transfers */
FSL_ESPI_WRITE(sc, ESPI_SPIM, 0);
device_add_child(dev, "spibus", -1);
return (bus_generic_attach(dev));
}
static int
fsl_espi_detach(device_t dev)
{
struct fsl_espi_softc *sc;
bus_generic_detach(dev);
sc = device_get_softc(dev);
FSL_ESPI_WRITE(sc, ESPI_SPMODE, 0);
sc = device_get_softc(dev);
mtx_destroy(&sc->sc_mtx);
if (sc->sc_intrhand)
bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
if (sc->sc_irq_res)
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (0);
}
static void
fsl_espi_fill_fifo(struct fsl_espi_softc *sc)
{
struct spi_command *cmd;
uint32_t spier, written;
uint8_t *data;
cmd = sc->sc_cmd;
spier = FSL_ESPI_READ(sc, ESPI_SPIE);
while (sc->sc_written < sc->sc_len &&
(spier & ESPI_SPIE_TNF)) {
data = (uint8_t *)cmd->tx_cmd;
written = sc->sc_written++;
if (written >= cmd->tx_cmd_sz) {
data = (uint8_t *)cmd->tx_data;
written -= cmd->tx_cmd_sz;
}
FSL_ESPI_WRITE_FIFO(sc, ESPI_SPITF, data[written]);
spier = FSL_ESPI_READ(sc, ESPI_SPIE);
}
}
static void
fsl_espi_drain_fifo(struct fsl_espi_softc *sc)
{
struct spi_command *cmd;
uint32_t spier, read;
uint8_t *data;
uint8_t r;
cmd = sc->sc_cmd;
spier = FSL_ESPI_READ(sc, ESPI_SPIE);
while (sc->sc_read < sc->sc_len && (spier & ESPI_SPIE_RNE)) {
data = (uint8_t *)cmd->rx_cmd;
read = sc->sc_read++;
if (read >= cmd->rx_cmd_sz) {
data = (uint8_t *)cmd->rx_data;
read -= cmd->rx_cmd_sz;
}
r = FSL_ESPI_READ_FIFO(sc, ESPI_SPIRF);
data[read] = r;
spier = FSL_ESPI_READ(sc, ESPI_SPIE);
}
}
static void
fsl_espi_intr(void *arg)
{
struct fsl_espi_softc *sc;
uint32_t spie;
sc = (struct fsl_espi_softc *)arg;
FSL_ESPI_LOCK(sc);
/* Filter stray interrupts. */
if ((sc->sc_flags & FSL_ESPI_BUSY) == 0) {
FSL_ESPI_UNLOCK(sc);
return;
}
spie = FSL_ESPI_READ(sc, ESPI_SPIE);
FSL_ESPI_WRITE(sc, ESPI_SPIE, spie);
/* TX - Fill up the FIFO. */
fsl_espi_fill_fifo(sc);
/* RX - Drain the FIFO. */
fsl_espi_drain_fifo(sc);
/* Check for end of transfer. */
if (spie & ESPI_SPIE_DON)
wakeup(sc->sc_dev);
FSL_ESPI_UNLOCK(sc);
}
static int
fsl_espi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct fsl_espi_softc *sc;
u_long plat_clk;
uint32_t csmode, spi_clk, spi_mode;
int cs, err, pm;
sc = device_get_softc(dev);
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"));
/* Restrict transmit length to command max length */
if (cmd->tx_cmd_sz + cmd->tx_data_sz > ESPI_SPCOM_TRANLEN_M + 1) {
return (EINVAL);
}
/* Get the proper chip select for this child. */
spibus_get_cs(child, &cs);
if (cs < 0 || cs > sc->sc_num_cs) {
device_printf(dev,
"Invalid chip select %d requested by %s\n", cs,
device_get_nameunit(child));
return (EINVAL);
}
spibus_get_clock(child, &spi_clk);
spibus_get_mode(child, &spi_mode);
FSL_ESPI_LOCK(sc);
/* If the controller is in use wait until it is available. */
while (sc->sc_flags & FSL_ESPI_BUSY)
mtx_sleep(dev, &sc->sc_mtx, 0, "fsl_espi", 0);
/* Now we have control over SPI controller. */
sc->sc_flags = FSL_ESPI_BUSY;
/* Save a pointer to the SPI command. */
sc->sc_cmd = cmd;
sc->sc_read = 0;
sc->sc_written = 0;
sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
plat_clk = mpc85xx_get_system_clock();
spi_clk = max(spi_clk, plat_clk / (16 * 16));
if (plat_clk == 0) {
device_printf(dev,
"unable to get platform clock, giving up.\n");
return (EINVAL);
}
csmode = 0;
if (plat_clk > spi_clk * 16 * 2) {
csmode |= ESPI_CSMODE_DIV16;
plat_clk /= 16;
}
pm = howmany(plat_clk, spi_clk * 2) - 1;
if (pm < 0)
pm = 1;
if (pm > 15)
pm = 15;
csmode |= (pm << ESPI_CSMODE_PM_S);
csmode |= ESPI_CSMODE_REV;
if (spi_mode == SPIBUS_MODE_CPOL || spi_mode == SPIBUS_MODE_CPOL_CPHA)
csmode |= ESPI_CSMODE_CI;
if (spi_mode == SPIBUS_MODE_CPHA || spi_mode == SPIBUS_MODE_CPOL_CPHA)
csmode |= ESPI_CSMODE_CP;
if (!(cs & SPIBUS_CS_HIGH))
csmode |= ESPI_CSMODE_POL;
csmode |= ESPI_CSMODE_LEN(7);/* Only deal with 8-bit characters. */
csmode |= ESPI_CSMODE_CSCG(1); /* XXX: Make this configurable? */
/* Configure transaction */
FSL_ESPI_WRITE(sc, ESPI_SPCOM, (cs << ESPI_SPCOM_CS_S) | (sc->sc_len - 1));
FSL_ESPI_WRITE(sc, ESPI_CSMODE(cs), csmode);
/* Enable interrupts we need. */
FSL_ESPI_WRITE(sc, ESPI_SPIM,
ESPI_SPIE_TXE | ESPI_SPIE_DON | ESPI_SPIE_RXF);
/* Wait for the transaction to complete. */
err = mtx_sleep(dev, &sc->sc_mtx, 0, "fsl_espi", hz * 2);
FSL_ESPI_WRITE(sc, ESPI_SPIM, 0);
/* Release the controller and wakeup the next thread waiting for it. */
sc->sc_flags = 0;
wakeup_one(dev);
FSL_ESPI_UNLOCK(sc);
/*
* Check for transfer timeout. The SPI controller doesn't
* return errors.
*/
if (err == EWOULDBLOCK) {
device_printf(sc->sc_dev, "SPI error\n");
err = EIO;
}
return (err);
}
static phandle_t
fsl_espi_get_node(device_t bus, device_t dev)
{
/* We only have one child, the SPI bus, which needs our own node. */
return (ofw_bus_get_node(bus));
}
static device_method_t fsl_espi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, fsl_espi_probe),
DEVMETHOD(device_attach, fsl_espi_attach),
DEVMETHOD(device_detach, fsl_espi_detach),
/* SPI interface */
DEVMETHOD(spibus_transfer, fsl_espi_transfer),
/* ofw_bus interface */
DEVMETHOD(ofw_bus_get_node, fsl_espi_get_node),
DEVMETHOD_END
};
static driver_t fsl_espi_driver = {
"spi",
fsl_espi_methods,
sizeof(struct fsl_espi_softc),
};
DRIVER_MODULE(fsl_espi, simplebus, fsl_espi_driver, 0, 0);
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