Hi Mike,
On Sun, Jan 22, 2012 at 10:30 PM, Mike Frysinger vapier@gentoo.org wrote:
This adds a SPI framework for people to hook up simulated SPI clients.
Signed-off-by: Mike Frysinger vapier@gentoo.org
arch/sandbox/include/asm/spi.h | 33 +++++++ drivers/spi/Makefile | 1 + drivers/spi/sandbox_spi.c | 183 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 217 insertions(+), 0 deletions(-) create mode 100644 arch/sandbox/include/asm/spi.h create mode 100644 drivers/spi/sandbox_spi.c
I don't know the SPI interface as well as use - might be useful to have a few comments and debug() things when things go wrong I think. Please see below for some ideas.
diff --git a/arch/sandbox/include/asm/spi.h b/arch/sandbox/include/asm/spi.h new file mode 100644 index 0000000..082df37 --- /dev/null +++ b/arch/sandbox/include/asm/spi.h @@ -0,0 +1,33 @@ +/*
- Simulate a SPI port and clients
- Copyright (c) 2011-2012 The Chromium OS Authors.
- See file CREDITS for list of people who contributed to this
- project.
- Licensed under the GPL-2 or later.
- */
+#ifndef __ASM_SPI_H__ +#define __ASM_SPI_H__
+#include <linux/types.h>
+struct sb_spi_emu_ops {
- int (*setup)(void **priv, const char *spec);
- void (*free)(void *priv);
- void (*cs_activate)(void *priv);
- void (*cs_deactivate)(void *priv);
- int (*xfer)(void *priv, const u8 *tx, u8 *rx, uint bytes);
+};
I think this could do with some comments.
+static inline void sb_spi_tristate(u8 *buf, uint len)
What does this do - comments?
+{
- /*
- * XXX: make this into a user config option ? let them pick
- * whether this is pulled low, or high, or tristates.
- */
- memset(buf, 0xff, len);
+}
+#endif diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index c967d87..d80ff8b 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -40,6 +40,7 @@ COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o COBJS-$(CONFIG_MXS_SPI) += mxs_spi.o COBJS-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o +COBJS-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o COBJS-$(CONFIG_SH_SPI) += sh_spi.o COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o diff --git a/drivers/spi/sandbox_spi.c b/drivers/spi/sandbox_spi.c new file mode 100644 index 0000000..eda0f3e --- /dev/null +++ b/drivers/spi/sandbox_spi.c @@ -0,0 +1,183 @@ +/*
- Simulate a SPI port
- Copyright (c) 2011-2012 The Chromium OS Authors.
- See file CREDITS for list of people who contributed to this
- project.
- Licensed under the GPL-2 or later.
- */
+#include <common.h> +#include <malloc.h> +#include <spi.h> +#include <os.h>
+#include <asm/spi.h>
+#ifndef CONFIG_SPI_IDLE_VAL +# define CONFIG_SPI_IDLE_VAL 0xFF +#endif
+struct sb_spi_slave {
- struct spi_slave slave;
- const char *spec;
- const struct sb_spi_emu_ops *ops;
- void *priv;
+};
+#define to_sb_spi_slave(s) container_of(s, struct sb_spi_slave, slave)
+static const char *sb_lookup_arg(unsigned int bus, unsigned int cs) +{
- char sf_arg[20];
blank line?
- sprintf(sf_arg, "--spi-%u-%u", bus, cs);
- return os_getopt(sf_arg, 1);
+}
+static const struct {
- const char *spec;
- const struct sb_spi_emu_ops *ops;
+} sb_emu_map[] = { +};
+static int sb_parse_type(struct sb_spi_slave *sss) +{
- size_t i;
- for (i = 0; i < ARRAY_SIZE(sb_emu_map); ++i) {
- size_t len = strlen(sb_emu_map[i].spec);
- const char *sub_spec = sss->spec + len;
- sss->ops = sb_emu_map[i].ops;
- if (!memcmp(sss->spec, sb_emu_map[i].spec, len) &&
- sss->spec[len] == ':')
- return sss->ops->setup(&sss->priv, sub_spec + 1);
- }
- return 1;
+}
+int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{
- return sb_lookup_arg(bus, cs) ? 1 : 0;
+}
+void spi_cs_activate(struct spi_slave *slave) +{
- struct sb_spi_slave *sss = to_sb_spi_slave(slave);
- if (sss->ops->cs_activate)
- sss->ops->cs_activate(sss->priv);
+}
+void spi_cs_deactivate(struct spi_slave *slave) +{
- struct sb_spi_slave *sss = to_sb_spi_slave(slave);
- if (sss->ops->cs_deactivate)
- sss->ops->cs_deactivate(sss->priv);
+}
+void spi_init(void) +{ +}
+void spi_set_speed(struct spi_slave *slave, uint hz) +{
Should this store the value somewhere?
+}
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
- unsigned int max_hz, unsigned int mode)
+{
- struct sb_spi_slave *sss;
- if (!spi_cs_is_valid(bus, cs))
- return NULL;
- sss = malloc(sizeof(*sss));
- if (!sss)
- return NULL;
Do we want a debug() message for this?
- sss->spec = sb_lookup_arg(bus, cs);
- if (sb_parse_type(sss)) {
- free(sss);
- printf("sandbox_spi: unable to locate a slave client\n");
- return NULL;
- }
- return &sss->slave;
+}
+void spi_free_slave(struct spi_slave *slave) +{
- struct sb_spi_slave *sss = to_sb_spi_slave(slave);
- if (sss->ops->free)
- sss->ops->free(sss->priv);
- free(sss);
+}
+int spi_claim_bus(struct spi_slave *slave) +{
Should we track claim/release for debugging purposes?
- return 0;
+}
+void spi_release_bus(struct spi_slave *slave) +{ +}
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
- void *din, unsigned long flags)
+{
- struct sb_spi_slave *sss = to_sb_spi_slave(slave);
- uint bytes = bitlen / 8, i;
- int ret = 0;
- u8 *tx = (void *)dout, *rx = din;
- if (bitlen == 0)
- goto done;
- /* we can only do 8 bit transfers */
- if (bitlen % 8) {
- flags |= SPI_XFER_END;
- goto done;
- }
debug() on these perhaps?
- if (flags & SPI_XFER_BEGIN)
- spi_cs_activate(slave);
- /* make sure rx/tx buffers are full so clients can assume */
- if (!tx) {
- tx = malloc(bytes);
- if (tx)
- memset(tx, CONFIG_SPI_IDLE_VAL, bytes);
- }
- if (!rx)
- rx = malloc(bytes);
- if (tx && rx) {
- debug("sb_xfer: bytes = %u\n tx:", bytes);
- for (i = 0; i < bytes; ++i)
- debug(" %u:%02x", i, tx[i]);
- debug("\n");
- ret = sss->ops->xfer(sss->priv, tx, rx, bytes);
- debug("sb_xfer: got back %i (that's %s)\n rx:",
- ret, ret ? "bad" : "good");
- for (i = 0; i < bytes; ++i)
- debug(" %u:%02x", i, rx[i]);
- debug("\n");
- }
debug() message if rx / tx is NULL?
- if (tx != dout)
- free(tx);
- if (rx != din)
- free(rx);
- done:
- if (flags & SPI_XFER_END)
- spi_cs_deactivate(slave);
- return ret;
+}
1.7.8.3