From 78f47b7353ebe1f243203dcc1ce0a2a374c08a40 Mon Sep 17 00:00:00 2001 From: Allen Martin Date: Sat, 16 Mar 2013 18:58:07 +0000 Subject: spi: add common fdt SPI driver interface Add a common interface to fdt based SPI drivers. Each driver is represented by a table entry in fdt_spi_drivers[]. If there are multiple SPI drivers in the table, the first driver to return success from spi_init() will be registered as the SPI driver. Signed-off-by: Allen Martin Signed-off-by: Tom Warren Reviewed-by: Stephen Warren --- drivers/spi/fdt_spi.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 drivers/spi/fdt_spi.c (limited to 'drivers/spi/fdt_spi.c') diff --git a/drivers/spi/fdt_spi.c b/drivers/spi/fdt_spi.c new file mode 100644 index 0000000000..c6ae719d63 --- /dev/null +++ b/drivers/spi/fdt_spi.c @@ -0,0 +1,171 @@ +/* + * Common fdt based SPI driver front end + * + * Copyright (c) 2013 NVIDIA Corporation + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +DECLARE_GLOBAL_DATA_PTR; + +struct fdt_spi_driver { + int compat; + int max_ctrls; + int (*init)(int *node_list, int count); + int (*claim_bus)(struct spi_slave *slave); + int (*release_bus)(struct spi_slave *slave); + int (*cs_is_valid)(unsigned int bus, unsigned int cs); + struct spi_slave *(*setup_slave)(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode); + void (*free_slave)(struct spi_slave *slave); + void (*cs_activate)(struct spi_slave *slave); + void (*cs_deactivate)(struct spi_slave *slave); + int (*xfer)(struct spi_slave *slave, unsigned int bitlen, + const void *data_out, void *data_in, unsigned long flags); +}; + +static struct fdt_spi_driver fdt_spi_drivers[] = { +#ifdef CONFIG_TEGRA20_SFLASH + { + .compat = COMPAT_NVIDIA_TEGRA20_SFLASH, + .max_ctrls = 1, + .init = tegra20_spi_init, + .claim_bus = tegra20_spi_claim_bus, + .cs_is_valid = tegra20_spi_cs_is_valid, + .setup_slave = tegra20_spi_setup_slave, + .free_slave = tegra20_spi_free_slave, + .cs_activate = tegra20_spi_cs_activate, + .cs_deactivate = tegra20_spi_cs_deactivate, + .xfer = tegra20_spi_xfer, + }, +#endif +#ifdef CONFIG_TEGRA20_SLINK + { + .compat = COMPAT_NVIDIA_TEGRA20_SLINK, + .max_ctrls = CONFIG_TEGRA_SLINK_CTRLS, + .init = tegra30_spi_init, + .claim_bus = tegra30_spi_claim_bus, + .cs_is_valid = tegra30_spi_cs_is_valid, + .setup_slave = tegra30_spi_setup_slave, + .free_slave = tegra30_spi_free_slave, + .cs_activate = tegra30_spi_cs_activate, + .cs_deactivate = tegra30_spi_cs_deactivate, + .xfer = tegra30_spi_xfer, + }, +#endif +}; + +static struct fdt_spi_driver *driver; + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + if (!driver) + return 0; + else if (!driver->cs_is_valid) + return 1; + else + return driver->cs_is_valid(bus, cs); +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + if (!driver || !driver->setup_slave) + return NULL; + + return driver->setup_slave(bus, cs, max_hz, mode); +} + +void spi_free_slave(struct spi_slave *slave) +{ + if (driver && driver->free_slave) + return driver->free_slave(slave); +} + +static int spi_init_driver(struct fdt_spi_driver *driver) +{ + int count; + int node_list[driver->max_ctrls]; + + count = fdtdec_find_aliases_for_id(gd->fdt_blob, "spi", + driver->compat, + node_list, + driver->max_ctrls); + return driver->init(node_list, count); +} + +void spi_init(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(fdt_spi_drivers); i++) { + driver = &fdt_spi_drivers[i]; + if (!spi_init_driver(driver)) + break; + } + if (i == ARRAY_SIZE(fdt_spi_drivers)) + driver = NULL; +} + +int spi_claim_bus(struct spi_slave *slave) +{ + if (!driver) + return 1; + if (!driver->claim_bus) + return 0; + + return driver->claim_bus(slave); +} + +void spi_release_bus(struct spi_slave *slave) +{ + if (driver && driver->release_bus) + driver->release_bus(slave); +} + +void spi_cs_activate(struct spi_slave *slave) +{ + if (driver && driver->cs_activate) + driver->cs_activate(slave); +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + if (driver && driver->cs_deactivate) + driver->cs_deactivate(slave); +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *data_out, void *data_in, unsigned long flags) +{ + if (!driver || !driver->xfer) + return -1; + + return driver->xfer(slave, bitlen, data_out, data_in, flags); +} -- cgit v1.2.1