freebsd-dev/sys/arm/allwinner/aw_spi.c

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2018-05-17 10:25:01 +00:00
/*-
* Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.org>
*
* 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 ``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 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/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/resource.h>
#include <machine/bus.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 <dev/extres/clk/clk.h>
#include <dev/extres/hwreset/hwreset.h>
#include "spibus_if.h"
#define AW_SPI_GCR 0x04 /* Global Control Register */
#define AW_SPI_GCR_EN (1 << 0) /* ENable */
#define AW_SPI_GCR_MODE_MASTER (1 << 1) /* 1 = Master, 0 = Slave */
#define AW_SPI_GCR_TP_EN (1 << 7) /* 1 = Stop transmit when FIFO is full */
#define AW_SPI_GCR_SRST (1 << 31) /* Soft Reset */
#define AW_SPI_TCR 0x08 /* Transfer Control register */
#define AW_SPI_TCR_XCH (1 << 31) /* Initiate transfer */
#define AW_SPI_TCR_SDDM (1 << 14) /* Sending Delay Data Mode */
#define AW_SPI_TCR_SDM (1 << 13) /* Master Sample Data Mode */
#define AW_SPI_TCR_FBS (1 << 12) /* First Transmit Bit Select (1 == LSB) */
#define AW_SPI_TCR_SDC (1 << 11) /* Master Sample Data Control */
#define AW_SPI_TCR_RPSM (1 << 10) /* Rapid Mode Select */
#define AW_SPI_TCR_DDB (1 << 9) /* Dummy Burst Type */
#define AW_SPI_TCR_SSSEL_MASK 0x30 /* Chip select */
#define AW_SPI_TCR_SSSEL_SHIFT 4
#define AW_SPI_TCR_SS_LEVEL (1 << 7) /* 1 == CS High */
#define AW_SPI_TCR_SS_OWNER (1 << 6) /* 1 == Software controlled */
#define AW_SPI_TCR_SPOL (1 << 2) /* 1 == Active low */
#define AW_SPI_TCR_CPOL (1 << 1) /* 1 == Active low */
#define AW_SPI_TCR_CPHA (1 << 0) /* 1 == Phase 1 */
#define AW_SPI_IER 0x10 /* Interrupt Control Register */
#define AW_SPI_IER_SS (1 << 13) /* Chip select went from valid to invalid */
#define AW_SPI_IER_TC (1 << 12) /* Transfer complete */
#define AW_SPI_IER_TF_UDR (1 << 11) /* TXFIFO underrun */
#define AW_SPI_IER_TF_OVF (1 << 10) /* TXFIFO overrun */
#define AW_SPI_IER_RF_UDR (1 << 9) /* RXFIFO underrun */
#define AW_SPI_IER_RF_OVF (1 << 8) /* RXFIFO overrun */
#define AW_SPI_IER_TF_FULL (1 << 6) /* TXFIFO Full */
#define AW_SPI_IER_TF_EMP (1 << 5) /* TXFIFO Empty */
#define AW_SPI_IER_TF_ERQ (1 << 4) /* TXFIFO Empty Request */
#define AW_SPI_IER_RF_FULL (1 << 2) /* RXFIFO Full */
#define AW_SPI_IER_RF_EMP (1 << 1) /* RXFIFO Empty */
#define AW_SPI_IER_RF_ERQ (1 << 0) /* RXFIFO Empty Request */
#define AW_SPI_ISR 0x14 /* Interrupt Status Register */
#define AW_SPI_FCR 0x18 /* FIFO Control Register */
#define AW_SPI_FCR_TX_RST (1 << 31) /* Reset TX FIFO */
#define AW_SPI_FCR_TX_TRIG_MASK 0xFF0000 /* TX FIFO Trigger level */
#define AW_SPI_FCR_TX_TRIG_SHIFT 16
#define AW_SPI_FCR_RX_RST (1 << 15) /* Reset RX FIFO */
#define AW_SPI_FCR_RX_TRIG_MASK 0xFF /* RX FIFO Trigger level */
#define AW_SPI_FCR_RX_TRIG_SHIFT 0
#define AW_SPI_FSR 0x1C /* FIFO Status Register */
#define AW_SPI_FSR_TB_WR (1 << 31)
#define AW_SPI_FSR_TB_CNT_MASK 0x70000000
#define AW_SPI_FSR_TB_CNT_SHIFT 28
#define AW_SPI_FSR_TF_CNT_MASK 0xFF0000
#define AW_SPI_FSR_TF_CNT_SHIFT 16
#define AW_SPI_FSR_RB_WR (1 << 15)
#define AW_SPI_FSR_RB_CNT_MASK 0x7000
#define AW_SPI_FSR_RB_CNT_SHIFT 12
#define AW_SPI_FSR_RF_CNT_MASK 0xFF
#define AW_SPI_FSR_RF_CNT_SHIFT 0
#define AW_SPI_WCR 0x20 /* Wait Clock Counter Register */
#define AW_SPI_CCR 0x24 /* Clock Rate Control Register */
#define AW_SPI_CCR_DRS (1 << 12) /* Clock divider select */
#define AW_SPI_CCR_CDR1_MASK 0xF00
#define AW_SPI_CCR_CDR1_SHIFT 8
#define AW_SPI_CCR_CDR2_MASK 0xFF
#define AW_SPI_CCR_CDR2_SHIFT 0
#define AW_SPI_MBC 0x30 /* Burst Counter Register */
#define AW_SPI_MTC 0x34 /* Transmit Counter Register */
#define AW_SPI_BCC 0x38 /* Burst Control Register */
#define AW_SPI_MDMA_CTL 0x88 /* Normal DMA Control Register */
#define AW_SPI_TXD 0x200 /* TX Data Register */
#define AW_SPI_RDX 0x300 /* RX Data Register */
#define AW_SPI_MAX_CS 4
#define AW_SPI_FIFO_SIZE 64
static struct ofw_compat_data compat_data[] = {
{ "allwinner,sun8i-h3-spi", 1 },
{ NULL, 0 }
};
static struct resource_spec aw_spi_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ SYS_RES_IRQ, 0, RF_ACTIVE | RF_SHAREABLE },
{ -1, 0 }
};
struct aw_spi_softc {
device_t dev;
device_t spibus;
struct resource *res[2];
struct mtx mtx;
clk_t clk_ahb;
clk_t clk_mod;
uint64_t mod_freq;
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hwreset_t rst_ahb;
void * intrhand;
int transfer;
uint8_t *rxbuf;
uint32_t rxcnt;
uint8_t *txbuf;
uint32_t txcnt;
uint32_t txlen;
uint32_t rxlen;
};
#define AW_SPI_LOCK(sc) mtx_lock(&(sc)->mtx)
#define AW_SPI_UNLOCK(sc) mtx_unlock(&(sc)->mtx)
#define AW_SPI_ASSERT_LOCKED(sc) mtx_assert(&(sc)->mtx, MA_OWNED)
#define AW_SPI_READ_1(sc, reg) bus_read_1((sc)->res[0], (reg))
#define AW_SPI_WRITE_1(sc, reg, val) bus_write_1((sc)->res[0], (reg), (val))
#define AW_SPI_READ_4(sc, reg) bus_read_4((sc)->res[0], (reg))
#define AW_SPI_WRITE_4(sc, reg, val) bus_write_4((sc)->res[0], (reg), (val))
static int aw_spi_probe(device_t dev);
static int aw_spi_attach(device_t dev);
static int aw_spi_detach(device_t dev);
static void aw_spi_intr(void *arg);
static int
aw_spi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
return (ENXIO);
device_set_desc(dev, "Allwinner SPI");
return (BUS_PROBE_DEFAULT);
}
static int
aw_spi_attach(device_t dev)
{
struct aw_spi_softc *sc;
int error;
sc = device_get_softc(dev);
sc->dev = dev;
mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
if (bus_alloc_resources(dev, aw_spi_spec, sc->res) != 0) {
device_printf(dev, "cannot allocate resources for device\n");
error = ENXIO;
goto fail;
}
if (bus_setup_intr(dev, sc->res[1],
INTR_TYPE_MISC | INTR_MPSAFE, NULL, aw_spi_intr, sc,
&sc->intrhand)) {
bus_release_resources(dev, aw_spi_spec, sc->res);
device_printf(dev, "cannot setup interrupt handler\n");
return (ENXIO);
}
/* De-assert reset */
if (hwreset_get_by_ofw_idx(dev, 0, 0, &sc->rst_ahb) == 0) {
error = hwreset_deassert(sc->rst_ahb);
if (error != 0) {
device_printf(dev, "cannot de-assert reset\n");
goto fail;
}
}
/* Activate the module clock. */
error = clk_get_by_ofw_name(dev, 0, "ahb", &sc->clk_ahb);
if (error != 0) {
device_printf(dev, "cannot get ahb clock\n");
goto fail;
}
error = clk_get_by_ofw_name(dev, 0, "mod", &sc->clk_mod);
if (error != 0) {
device_printf(dev, "cannot get mod clock\n");
goto fail;
}
error = clk_enable(sc->clk_ahb);
if (error != 0) {
device_printf(dev, "cannot enable ahb clock\n");
goto fail;
}
error = clk_enable(sc->clk_mod);
if (error != 0) {
device_printf(dev, "cannot enable mod clock\n");
goto fail;
}
sc->spibus = device_add_child(dev, "spibus", -1);
return (0);
fail:
aw_spi_detach(dev);
return (error);
}
static int
aw_spi_detach(device_t dev)
{
struct aw_spi_softc *sc;
sc = device_get_softc(dev);
bus_generic_detach(sc->dev);
if (sc->spibus != NULL)
device_delete_child(dev, sc->spibus);
if (sc->clk_mod != NULL)
clk_release(sc->clk_mod);
if (sc->clk_ahb)
clk_release(sc->clk_ahb);
if (sc->rst_ahb)
hwreset_assert(sc->rst_ahb);
if (sc->intrhand != NULL)
bus_teardown_intr(sc->dev, sc->res[1], sc->intrhand);
bus_release_resources(dev, aw_spi_spec, sc->res);
mtx_destroy(&sc->mtx);
return (0);
}
static phandle_t
aw_spi_get_node(device_t bus, device_t dev)
{
return ofw_bus_get_node(bus);
}
static void
aw_spi_setup_mode(struct aw_spi_softc *sc, uint32_t mode)
{
uint32_t reg;
/* We only support master mode */
reg = AW_SPI_READ_4(sc, AW_SPI_GCR);
reg |= AW_SPI_GCR_MODE_MASTER;
AW_SPI_WRITE_4(sc, AW_SPI_GCR, reg);
/* Setup the modes */
reg = AW_SPI_READ_4(sc, AW_SPI_TCR);
if (mode & SPIBUS_MODE_CPHA)
reg |= AW_SPI_TCR_CPHA;
if (mode & SPIBUS_MODE_CPOL)
reg |= AW_SPI_TCR_CPOL;
AW_SPI_WRITE_4(sc, AW_SPI_TCR, reg);
}
static void
aw_spi_setup_cs(struct aw_spi_softc *sc, uint32_t cs, bool low)
{
uint32_t reg;
/* Setup CS */
reg = AW_SPI_READ_4(sc, AW_SPI_TCR);
reg &= ~(AW_SPI_TCR_SSSEL_MASK);
reg |= cs << AW_SPI_TCR_SSSEL_SHIFT;
reg |= AW_SPI_TCR_SS_OWNER;
if (low)
reg &= ~(AW_SPI_TCR_SS_LEVEL);
else
reg |= AW_SPI_TCR_SS_LEVEL;
AW_SPI_WRITE_4(sc, AW_SPI_TCR, reg);
}
static uint64_t
aw_spi_clock_test_cdr1(struct aw_spi_softc *sc, uint64_t clock, uint32_t *ccr)
{
uint64_t cur, best = 0;
int i, max, best_div;
max = AW_SPI_CCR_CDR1_MASK >> AW_SPI_CCR_CDR1_SHIFT;
for (i = 0; i < max; i++) {
cur = sc->mod_freq / (1 << i);
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if ((clock - cur) < (clock - best)) {
best = cur;
best_div = i;
}
}
*ccr = (best_div << AW_SPI_CCR_CDR1_SHIFT);
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return (best);
}
static uint64_t
aw_spi_clock_test_cdr2(struct aw_spi_softc *sc, uint64_t clock, uint32_t *ccr)
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{
uint64_t cur, best = 0;
int i, max, best_div;
max = ((AW_SPI_CCR_CDR2_MASK) >> AW_SPI_CCR_CDR2_SHIFT);
for (i = 0; i < max; i++) {
cur = sc->mod_freq / (2 * i + 1);
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if ((clock - cur) < (clock - best)) {
best = cur;
best_div = i;
}
}
*ccr = AW_SPI_CCR_DRS | (best_div << AW_SPI_CCR_CDR2_SHIFT);
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return (best);
}
static void
aw_spi_setup_clock(struct aw_spi_softc *sc, uint64_t clock)
{
uint64_t best_ccr1, best_ccr2;
uint32_t ccr, ccr1, ccr2;
best_ccr1 = aw_spi_clock_test_cdr1(sc, clock, &ccr1);
best_ccr2 = aw_spi_clock_test_cdr2(sc, clock, &ccr2);
if (best_ccr1 == clock) {
ccr = ccr1;
} else if (best_ccr2 == clock) {
ccr = ccr2;
} else {
if ((clock - best_ccr1) < (clock - best_ccr2))
ccr = ccr1;
else
ccr = ccr2;
}
AW_SPI_WRITE_4(sc, AW_SPI_CCR, ccr);
}
static inline void
aw_spi_fill_txfifo(struct aw_spi_softc *sc)
{
uint32_t reg, txcnt;
int i;
if (sc->txcnt == sc->txlen)
return;
reg = AW_SPI_READ_4(sc, AW_SPI_FSR);
reg &= AW_SPI_FSR_TF_CNT_MASK;
txcnt = reg >> AW_SPI_FSR_TF_CNT_SHIFT;
for (i = 0; i < (AW_SPI_FIFO_SIZE - txcnt); i++) {
AW_SPI_WRITE_1(sc, AW_SPI_TXD, sc->txbuf[sc->txcnt++]);
if (sc->txcnt == sc->txlen)
break;
}
return;
}
static inline void
aw_spi_read_rxfifo(struct aw_spi_softc *sc)
{
uint32_t reg;
uint8_t val;
int i;
if (sc->rxcnt == sc->rxlen)
return;
reg = AW_SPI_READ_4(sc, AW_SPI_FSR);
reg = (reg & AW_SPI_FSR_RF_CNT_MASK) >> AW_SPI_FSR_RF_CNT_SHIFT;
for (i = 0; i < reg; i++) {
val = AW_SPI_READ_1(sc, AW_SPI_RDX);
if (sc->rxcnt < sc->rxlen)
sc->rxbuf[sc->rxcnt++] = val;
}
}
static void
aw_spi_intr(void *arg)
{
struct aw_spi_softc *sc;
uint32_t intr;
sc = (struct aw_spi_softc *)arg;
intr = AW_SPI_READ_4(sc, AW_SPI_ISR);
if (intr & AW_SPI_IER_RF_FULL)
aw_spi_read_rxfifo(sc);
if (intr & AW_SPI_IER_TF_EMP) {
aw_spi_fill_txfifo(sc);
/*
* If we don't have anything else to write
* disable TXFifo interrupts
*/
if (sc->txcnt == sc->txlen)
AW_SPI_WRITE_4(sc, AW_SPI_IER, AW_SPI_IER_TC |
AW_SPI_IER_RF_FULL);
}
if (intr & AW_SPI_IER_TC) {
/* read the rest of the data from the fifo */
aw_spi_read_rxfifo(sc);
/* Disable the interrupts */
AW_SPI_WRITE_4(sc, AW_SPI_IER, 0);
sc->transfer = 0;
wakeup(sc);
}
/* Clear Interrupts */
AW_SPI_WRITE_4(sc, AW_SPI_ISR, intr);
}
static int
aw_spi_xfer(struct aw_spi_softc *sc, void *rxbuf, void *txbuf, uint32_t txlen, uint32_t rxlen)
{
uint32_t reg;
int error = 0, timeout;
sc->rxbuf = rxbuf;
sc->rxcnt = 0;
sc->txbuf = txbuf;
sc->txcnt = 0;
sc->txlen = txlen;
sc->rxlen = rxlen;
/* Reset the FIFOs */
AW_SPI_WRITE_4(sc, AW_SPI_FCR, AW_SPI_FCR_TX_RST | AW_SPI_FCR_RX_RST);
for (timeout = 1000; timeout > 0; timeout--) {
reg = AW_SPI_READ_4(sc, AW_SPI_FCR);
if (reg == 0)
break;
}
if (timeout == 0) {
device_printf(sc->dev, "Cannot reset the FIFOs\n");
return (EIO);
}
/* Write the counters */
AW_SPI_WRITE_4(sc, AW_SPI_MBC, txlen);
AW_SPI_WRITE_4(sc, AW_SPI_MTC, txlen);
AW_SPI_WRITE_4(sc, AW_SPI_BCC, txlen);
/* First fill */
aw_spi_fill_txfifo(sc);
/* Start transmit */
reg = AW_SPI_READ_4(sc, AW_SPI_TCR);
reg |= AW_SPI_TCR_XCH;
AW_SPI_WRITE_4(sc, AW_SPI_TCR, reg);
/*
* Enable interrupts for :
* Transmit complete
* TX Fifo empty
* RX Fifo full
*/
AW_SPI_WRITE_4(sc, AW_SPI_IER, AW_SPI_IER_TC |
AW_SPI_IER_TF_EMP | AW_SPI_IER_RF_FULL);
sc->transfer = 1;
while (error == 0 && sc->transfer != 0)
error = msleep(sc, &sc->mtx, 0, "aw_spi", 10 * hz);
return (0);
}
static int
aw_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
struct aw_spi_softc *sc;
uint32_t cs, mode, clock, reg;
int err = 0;
sc = device_get_softc(dev);
spibus_get_cs(child, &cs);
spibus_get_clock(child, &clock);
spibus_get_mode(child, &mode);
/* The minimum divider is 2 so set the clock at twice the needed speed */
clk_set_freq(sc->clk_mod, 2 * clock, CLK_SET_ROUND_DOWN);
clk_get_freq(sc->clk_mod, &sc->mod_freq);
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if (cs >= AW_SPI_MAX_CS) {
device_printf(dev, "Invalid cs %d\n", cs);
return (EINVAL);
}
mtx_lock(&sc->mtx);
/* Enable and reset the module */
reg = AW_SPI_READ_4(sc, AW_SPI_GCR);
reg |= AW_SPI_GCR_EN | AW_SPI_GCR_SRST;
AW_SPI_WRITE_4(sc, AW_SPI_GCR, reg);
/* Setup clock, CS and mode */
aw_spi_setup_clock(sc, clock);
aw_spi_setup_mode(sc, mode);
if (cs & SPIBUS_CS_HIGH)
aw_spi_setup_cs(sc, cs, false);
else
aw_spi_setup_cs(sc, cs, true);
/* xfer */
err = 0;
if (cmd->tx_cmd_sz > 0)
err = aw_spi_xfer(sc, cmd->rx_cmd, cmd->tx_cmd,
cmd->tx_cmd_sz, cmd->rx_cmd_sz);
if (cmd->tx_data_sz > 0 && err == 0)
err = aw_spi_xfer(sc, cmd->rx_data, cmd->tx_data,
cmd->tx_data_sz, cmd->rx_data_sz);
if (cs & SPIBUS_CS_HIGH)
aw_spi_setup_cs(sc, cs, true);
else
aw_spi_setup_cs(sc, cs, false);
/* Disable the module */
reg = AW_SPI_READ_4(sc, AW_SPI_GCR);
reg &= ~AW_SPI_GCR_EN;
AW_SPI_WRITE_4(sc, AW_SPI_GCR, reg);
mtx_unlock(&sc->mtx);
return (err);
}
static device_method_t aw_spi_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, aw_spi_probe),
DEVMETHOD(device_attach, aw_spi_attach),
DEVMETHOD(device_detach, aw_spi_detach),
/* spibus_if */
DEVMETHOD(spibus_transfer, aw_spi_transfer),
/* ofw_bus_if */
DEVMETHOD(ofw_bus_get_node, aw_spi_get_node),
DEVMETHOD_END
};
static driver_t aw_spi_driver = {
"aw_spi",
aw_spi_methods,
sizeof(struct aw_spi_softc),
};
static devclass_t aw_spi_devclass;
DRIVER_MODULE(aw_spi, simplebus, aw_spi_driver, aw_spi_devclass, 0, 0);
DRIVER_MODULE(ofw_spibus, aw_spi, ofw_spibus_driver, ofw_spibus_devclass, 0, 0);
MODULE_DEPEND(aw_spi, ofw_spibus, 1, 1, 1);
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SIMPLEBUS_PNP_INFO(compat_data);