Date: Sun, 2 Sep 2012 09:37:24 -0300 From: Luiz Otavio O Souza <loos.br@gmail.com> To: freebsd-arch@freebsd.org Subject: spibus access serialization Message-ID: <B54C4C9A-76F4-45CC-94C3-628DDF901051@gmail.com>
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--Apple-Mail-58-1062540785
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Hi,
I've some embedded systems with spi devices that share the same spibus =
and because of that i'm working to get some kind of access serialization =
on spibus and also protection to devices which need a series of spi =
transfers to achieve some goal.
The SPI usage (with all the patches applied) goes like this:
/* Wait until the spibus is free. When free, acquire the bus and select =
the device */
SPIBUS_ACQUIRE_BUS(spibus, device);
/* Program the CPLD to read data from NAND */
SPIBUS_TRANSFER(spibus, device, &cmd);
/* Read 'n' bytes from CPLD */
SPIBUS_TRANSFER(spibus, device, &cmd);
/* Release the spibus and deselect the device */
SPIBUS_RELEASE_BUS(spibus, device);
While today everything is done inside SPIBUS_TRANSFER().
The patch spibus-01.diff adds the bus methods and the default methods.
The spibus-02-devices.diff adds the needed glue to all spi devices =
(dev/flash/at45d.c, dev/flash/mx25l.c, arm/lpc/ssd1289.c, =
mips/atheros/pcf2123_rtc.c). As the default methods are just nops, there =
are no functional changes.
On spibus-03-controllers.diff we finally add the serialization methods =
to spi controllers (mips/atheros/ar71xx_spi.c and arm/lpc/lpc_spi.c) and =
change the device CS to happen on bus acquire and release and not on =
start and end of each transfer.
The spi controller on arm/at91/at91_spi.c wasn't changed because looks =
like it will be need to move the device CS control from the controller =
and use it as a GPIO pin. I need to read more of at91 code before i can =
suggest some change there. Until there it will work just as now (no =
serialization and selecting/deselecting the device within each =
transfer).
Comments ?
Thanks,
Luiz
--Apple-Mail-58-1062540785
Content-Disposition: attachment;
filename=spibus-01.diff
Content-Type: application/octet-stream;
name="spibus-01.diff"
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Index: dev/spibus/spibus.c
===================================================================
--- dev/spibus/spibus.c (revision 239916)
+++ dev/spibus/spibus.c (working copy)
@@ -155,6 +155,20 @@
resource_int_value(dname, dunit, "cs", &devi->cs);
}
+static void
+spibus_acquire_bus_impl(device_t dev, device_t child)
+{
+
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), child);
+}
+
+static void
+spibus_release_bus_impl(device_t dev, device_t child)
+{
+
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), child);
+}
+
static int
spibus_transfer_impl(device_t dev, device_t child, struct spi_command *cmd)
{
@@ -180,6 +194,8 @@
DEVMETHOD(bus_hinted_child, spibus_hinted_child),
/* spibus interface */
+ DEVMETHOD(spibus_acquire_bus, spibus_acquire_bus_impl),
+ DEVMETHOD(spibus_release_bus, spibus_release_bus_impl),
DEVMETHOD(spibus_transfer, spibus_transfer_impl),
DEVMETHOD_END
Index: dev/spibus/spibus_if.m
===================================================================
--- dev/spibus/spibus_if.m (revision 239916)
+++ dev/spibus/spibus_if.m (working copy)
@@ -32,6 +32,37 @@
INTERFACE spibus;
#
+# Default implementation
+#
+CODE {
+ static void
+ null_acquire_bus(device_t dev, device_t child)
+ {
+ }
+
+ static void
+ null_release_bus(device_t dev, device_t child)
+ {
+ }
+};
+
+#
+# Acquire bus and select the device
+#
+METHOD void acquire_bus {
+ device_t dev;
+ device_t child;
+} DEFAULT null_acquire_bus;
+
+#
+# Release bus and deselect the device
+#
+METHOD void release_bus {
+ device_t dev;
+ device_t child;
+} DEFAULT null_release_bus;
+
+#
# Do a spi command
#
METHOD int transfer {
--Apple-Mail-58-1062540785
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filename=spibus-02-devices.diff
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name="spibus-02-devices.diff"
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Index: dev/flash/at45d.c
===================================================================
--- dev/flash/at45d.c (revision 239916)
+++ dev/flash/at45d.c (working copy)
@@ -132,7 +132,9 @@
cmd.tx_cmd = txBuf;
cmd.rx_cmd = rxBuf;
cmd.rx_cmd_sz = cmd.tx_cmd_sz = 2;
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
*status = rxBuf[1];
return (err);
}
@@ -152,7 +154,9 @@
cmd.tx_cmd = &txBuf;
cmd.rx_cmd = &rxBuf;
cmd.tx_cmd_sz = cmd.rx_cmd_sz = 5;
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
if (err)
return (err);
memcpy(resp, rxBuf + 1, 4);
@@ -365,8 +369,10 @@
txBuf[2] = ((addr >> 8) & 0xff);
txBuf[3] = 0;
cmd.tx_data_sz = cmd.rx_data_sz = 0;
+ SPIBUS_ACQUIRE_BUS(pdev, dev);
err = SPIBUS_TRANSFER(pdev, dev,
&cmd);
+ SPIBUS_RELEASE_BUS(pdev, dev);
if (err == 0)
err = at45d_wait_ready(dev,
&status);
@@ -383,7 +389,9 @@
txBuf[2] = ((addr >> 8) & 0xff);
txBuf[3] = (addr & 0xff);
cmd.tx_data_sz = cmd.rx_data_sz = len;
+ SPIBUS_ACQUIRE_BUS(pdev, dev);
err = SPIBUS_TRANSFER(pdev, dev, &cmd);
+ SPIBUS_RELEASE_BUS(pdev, dev);
if (err == 0 && bp->bio_cmd != BIO_READ)
err = at45d_wait_ready(dev, &status);
if (err != 0) {
@@ -397,7 +405,9 @@
txBuf[2] = ((addr >> 8) & 0xff);
txBuf[3] = 0;
cmd.tx_data_sz = cmd.rx_data_sz = 0;
+ SPIBUS_ACQUIRE_BUS(pdev, dev);
err = SPIBUS_TRANSFER(pdev, dev, &cmd);
+ SPIBUS_RELEASE_BUS(pdev, dev);
if (err == 0)
err = at45d_wait_ready(dev, &status);
if (err != 0 || (status & 0x40) != 0) {
Index: dev/flash/mx25l.c
===================================================================
--- dev/flash/mx25l.c (revision 239916)
+++ dev/flash/mx25l.c (working copy)
@@ -123,7 +123,9 @@
cmd.rx_cmd = rxBuf;
cmd.rx_cmd_sz = 2;
cmd.tx_cmd_sz = 2;
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
return (rxBuf[1]);
}
@@ -157,7 +159,9 @@
*/
cmd.tx_cmd_sz = 4;
cmd.rx_cmd_sz = 4;
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
if (err)
return (NULL);
@@ -192,7 +196,9 @@
cmd.rx_cmd = rxBuf;
cmd.rx_cmd_sz = 1;
cmd.tx_cmd_sz = 1;
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
}
static void
@@ -217,7 +223,9 @@
txBuf[1] = ((sector >> 16) & 0xff);
txBuf[2] = ((sector >> 8) & 0xff);
txBuf[3] = (sector & 0xff);
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
}
static int
@@ -290,7 +298,9 @@
mx25l_wait_for_device_ready(dev);
mx25l_set_writable(dev, 1);
+ SPIBUS_ACQUIRE_BUS(pdev, dev);
err = SPIBUS_TRANSFER(pdev, dev, &cmd);
+ SPIBUS_RELEASE_BUS(pdev, dev);
if (err)
break;
@@ -339,7 +349,9 @@
cmd.rx_data = data;
cmd.rx_data_sz = count;
+ SPIBUS_ACQUIRE_BUS(pdev, dev);
err = SPIBUS_TRANSFER(pdev, dev, &cmd);
+ SPIBUS_RELEASE_BUS(pdev, dev);
return (err);
}
@@ -480,7 +492,7 @@
DEVMETHOD(device_attach, mx25l_attach),
DEVMETHOD(device_detach, mx25l_detach),
- { 0, 0 }
+ DEVMETHOD_END
};
static driver_t mx25l_driver = {
Index: arm/lpc/ssd1289.c
===================================================================
--- arm/lpc/ssd1289.c (revision 239916)
+++ arm/lpc/ssd1289.c (working copy)
@@ -179,6 +179,7 @@
{
uint8_t buffer[2];
+ SPIBUS_ACQUIRE_BUS(device_get_parent(sc->ss_dev), sc->ss_dev);
ssd1289_set_dc(sc, 0);
buffer[0] = 0x00;
buffer[1] = addr & 0xff;
@@ -188,6 +189,7 @@
buffer[0] = (value >> 8) & 0xff;
buffer[1] = value & 0xff;
ssd1289_spi_send(sc, buffer, 2);
+ SPIBUS_RELEASE_BUS(device_get_parent(sc->ss_dev), sc->ss_dev);
}
static device_method_t ssd1289_methods[] = {
@@ -195,7 +197,7 @@
DEVMETHOD(device_probe, ssd1289_probe),
DEVMETHOD(device_attach, ssd1289_attach),
- { 0, 0 }
+ DEVMETHOD_END
};
static devclass_t ssd1289_devclass;
Index: mips/atheros/pcf2123_rtc.c
===================================================================
--- mips/atheros/pcf2123_rtc.c (revision 239916)
+++ mips/atheros/pcf2123_rtc.c (working copy)
@@ -91,7 +91,9 @@
cmd.tx_cmd = txBuf;
cmd.rx_cmd_sz = sizeof(rxBuf);
cmd.tx_cmd_sz = sizeof(txBuf);
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
DELAY(PCF2123_DELAY);
return (0);
@@ -120,7 +122,9 @@
cmd.tx_cmd = txTimedate;
cmd.rx_cmd_sz = sizeof(rxTimedate);
cmd.tx_cmd_sz = sizeof(txTimedate);
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
DELAY(PCF2123_DELAY);
ct.nsec = 0;
@@ -178,7 +182,9 @@
txTimedate[6] = TOBCD(ct.mon);
txTimedate[7] = TOBCD(ct.year - YEAR_BASE);
+ SPIBUS_ACQUIRE_BUS(device_get_parent(dev), dev);
err = SPIBUS_TRANSFER(device_get_parent(dev), dev, &cmd);
+ SPIBUS_RELEASE_BUS(device_get_parent(dev), dev);
DELAY(PCF2123_DELAY);
return (err);
@@ -191,7 +197,7 @@
DEVMETHOD(clock_gettime, pcf2123_rtc_gettime),
DEVMETHOD(clock_settime, pcf2123_rtc_settime),
- { 0, 0 },
+ DEVMETHOD_END
};
static driver_t pcf2123_rtc_driver = {
--Apple-Mail-58-1062540785
Content-Disposition: attachment;
filename=spibus-03-controllers.diff
Content-Type: application/octet-stream;
name="spibus-03-controllers.diff"
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Index: mips/atheros/ar71xx_spi.c
===================================================================
--- mips/atheros/ar71xx_spi.c (revision 239916)
+++ mips/atheros/ar71xx_spi.c (working copy)
@@ -35,7 +35,9 @@
#include <sys/interrupt.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
+#include <sys/lock.h>
#include <sys/module.h>
+#include <sys/mutex.h>
#include <sys/rman.h>
#include <vm/vm.h>
@@ -76,10 +78,21 @@
struct ar71xx_spi_softc {
device_t sc_dev;
+ device_t sc_owner;
+ struct mtx sc_mtx;
struct resource *sc_mem_res;
uint32_t sc_reg_ctrl;
};
+#define AR71XX_SPI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
+#define AR71XX_SPI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
+#define AR71XX_SPI_LOCK_INIT(_sc) \
+ mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
+ "ar71xx_spi", MTX_DEF)
+#define AR71XX_SPI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx)
+#define AR71XX_SPI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED)
+#define AR71XX_SPI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED)
+
static int
ar71xx_spi_probe(device_t dev)
{
@@ -102,6 +115,7 @@
return (ENXIO);
}
+ AR71XX_SPI_LOCK_INIT(sc);
SPI_WRITE(sc, AR71XX_SPI_FS, 1);
sc->sc_reg_ctrl = SPI_READ(sc, AR71XX_SPI_CTRL);
@@ -133,6 +147,49 @@
SPI_WRITE(sc, AR71XX_SPI_IO_CTRL, SPI_IO_CTRL_CSMASK);
}
+static void
+ar71xx_spi_acquire_bus(device_t dev, device_t child)
+{
+ struct spibus_ivar *devi = SPIBUS_IVAR(child);
+ struct ar71xx_spi_softc *sc;
+
+ sc = device_get_softc(dev);
+ AR71XX_SPI_ASSERT_UNLOCKED(sc);
+
+ /* Wait until bus is free and then set the new bus owner. */
+ AR71XX_SPI_LOCK(sc);
+ while (sc->sc_owner != NULL) {
+ mtx_sleep(sc, &sc->sc_mtx, 0, "ar71xx_spi", 0);
+ }
+ sc->sc_owner = child;
+ AR71XX_SPI_UNLOCK(sc);
+
+ /* Select the SPI device. */
+ ar71xx_spi_chip_activate(sc, devi->cs);
+}
+
+static void
+ar71xx_spi_release_bus(device_t dev, device_t child)
+{
+ struct spibus_ivar *devi = SPIBUS_IVAR(child);
+ struct ar71xx_spi_softc *sc;
+
+ sc = device_get_softc(dev);
+ AR71XX_SPI_ASSERT_UNLOCKED(sc);
+
+ /* Free the SPI BUS. */
+ AR71XX_SPI_LOCK(sc);
+ if (sc->sc_owner == NULL)
+ panic("ar71xx_spi: releasing unowned bus.");
+ if (sc->sc_owner != child)
+ panic("ar71xx_spi: you don't own the bus. game over.");
+ sc->sc_owner = NULL;
+ AR71XX_SPI_UNLOCK(sc);
+
+ /* Deselect the SPI device. */
+ ar71xx_spi_chip_deactivate(sc, devi->cs);
+}
+
static uint8_t
ar71xx_spi_txrx(struct ar71xx_spi_softc *sc, int cs, uint8_t data)
{
@@ -173,7 +230,7 @@
sc = device_get_softc(dev);
- ar71xx_spi_chip_activate(sc, devi->cs);
+ KASSERT(sc->sc_owner != NULL, ("SPI transfer on unowned bus"));
KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
("TX/RX command sizes should be equal"));
@@ -196,8 +253,6 @@
for (i = 0; i < cmd->tx_data_sz; i++)
buf_in[i] = ar71xx_spi_txrx(sc, devi->cs, buf_out[i]);
- ar71xx_spi_chip_deactivate(sc, devi->cs);
-
return (0);
}
@@ -209,6 +264,8 @@
SPI_WRITE(sc, AR71XX_SPI_CTRL, sc->sc_reg_ctrl);
SPI_WRITE(sc, AR71XX_SPI_FS, 0);
+ AR71XX_SPI_LOCK_DESTROY(sc);
+
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
@@ -221,9 +278,11 @@
DEVMETHOD(device_attach, ar71xx_spi_attach),
DEVMETHOD(device_detach, ar71xx_spi_detach),
+ DEVMETHOD(spibus_acquire_bus, ar71xx_spi_acquire_bus),
+ DEVMETHOD(spibus_release_bus, ar71xx_spi_release_bus),
DEVMETHOD(spibus_transfer, ar71xx_spi_transfer),
- {0, 0}
+ DEVMETHOD_END
};
static driver_t ar71xx_spi_driver = {
Index: arm/lpc/lpc_spi.c
===================================================================
--- arm/lpc/lpc_spi.c (revision 239916)
+++ arm/lpc/lpc_spi.c (working copy)
@@ -67,6 +67,8 @@
struct lpc_spi_softc
{
device_t ls_dev;
+ device_t ls_owner;
+ struct mtx ls_mtx;
struct resource * ls_mem_res;
struct resource * ls_irq_res;
bus_space_tag_t ls_bst;
@@ -83,6 +85,15 @@
#define lpc_spi_write_4(_sc, _reg, _val) \
bus_space_write_4(_sc->ls_bst, _sc->ls_bsh, _reg, _val)
+#define LPC_SPI_LOCK(_sc) mtx_lock(&(_sc)->ls_mtx)
+#define LPC_SPI_UNLOCK(_sc) mtx_unlock(&(_sc)->ls_mtx)
+#define LPC_SPI_LOCK_INIT(_sc) \
+ mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->ls_dev), \
+ "lpc_spi", MTX_DEF)
+#define LPC_SPI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->ls_mtx)
+#define LPC_SPI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->ls_mtx, MA_OWNED)
+#define LPC_SPI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->ls_mtx, MA_NOTOWNED)
+
static int
lpc_spi_probe(device_t dev)
{
@@ -126,6 +137,8 @@
lpc_spi_write_4(sc, LPC_SSP_CR1, LPC_SSP_CR1_SSE);
lpc_spi_write_4(sc, LPC_SSP_CPSR, 128);
+ LPC_SPI_LOCK_INIT(sc);
+
device_add_child(dev, "spibus", 0);
return (bus_generic_attach(dev));
}
@@ -136,6 +149,49 @@
return (EBUSY);
}
+static void
+lpc_spi_acquire_bus(device_t dev, device_t child)
+{
+ struct spibus_ivar *devi = SPIBUS_IVAR(child);
+ struct lpc_spi_softc *sc;
+
+ sc = device_get_softc(dev);
+ LPC_SPI_ASSERT_UNLOCKED(sc);
+
+ /* Wait until bus is free and then set the new bus owner. */
+ LPC_SPI_LOCK(sc);
+ while (sc->ls_owner != NULL) {
+ mtx_sleep(sc, &sc->ls_mtx, 0, "lpc_spi", 0);
+ }
+ sc->ls_owner = child;
+ LPC_SPI_UNLOCK(sc);
+
+ /* Set CS active */
+ lpc_gpio_set_state(child, devi->cs, 0);
+}
+
+static void
+lpc_spi_release_bus(device_t dev, device_t child)
+{
+ struct spibus_ivar *devi = SPIBUS_IVAR(child);
+ struct ar71xx_spi_softc *sc;
+
+ sc = device_get_softc(dev);
+ LPC_SPI_ASSERT_UNLOCKED(sc);
+
+ /* Free the SPI BUS. */
+ LPC_SPI_LOCK(sc);
+ if (sc->ls_owner == NULL)
+ panic("lpc_spi: releasing unowned bus.");
+ if (sc->ls_owner != child)
+ panic("lpc_spi: you don't own the bus. game over.");
+ sc->ls_owner = NULL;
+ LPC_SPI_UNLOCK(sc);
+
+ /* Set CS inactive */
+ lpc_gpio_set_state(child, devi->cs, 1);
+}
+
static int
lpc_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
{
@@ -144,8 +200,7 @@
uint8_t *in_buf, *out_buf;
int i;
- /* Set CS active */
- lpc_gpio_set_state(child, devi->cs, 0);
+ KASSERT(sc->ls_owner != NULL, ("SPI transfer on unowned bus"));
/* Wait for FIFO to be ready */
while ((lpc_spi_read_4(sc, LPC_SSP_SR) & LPC_SSP_SR_TNF) == 0);
@@ -166,9 +221,6 @@
in_buf[i] = lpc_spi_read_4(sc, LPC_SSP_DR);
}
- /* Set CS inactive */
- lpc_gpio_set_state(child, devi->cs, 1);
-
return (0);
}
@@ -179,9 +231,11 @@
DEVMETHOD(device_detach, lpc_spi_detach),
/* SPI interface */
+ DEVMETHOD(spibus_acquire_bus, lpc_spi_acquire_bus),
+ DEVMETHOD(spibus_release_bus, lpc_spi_release_bus),
DEVMETHOD(spibus_transfer, lpc_spi_transfer),
- { 0, 0 }
+ DEVMETHOD_END
};
static devclass_t lpc_spi_devclass;
--Apple-Mail-58-1062540785--
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