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 <amartin@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

4 files changed, 197 insertions, 45 deletions

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 78e3d3d..3762d59 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -46,6 +46,7 @@ COBJS-$(CONFIG_OMAP3_SPI) += omap3_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
 COBJS-$(CONFIG_SH_SPI) += sh_spi.o
 COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
+COBJS-$(CONFIG_FDT_SPI) += fdt_spi.o
 COBJS-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 COBJS-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
 COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
diff --git a/drivers/spi/fdt_spi.c b/drivers/spi/fdt_spi.c
new file mode 100644
index 0000000..c6ae719
--- /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 <common.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/clk_rst.h>
+#include <asm/arch-tegra20/tegra20_sflash.h>
+#include <asm/arch-tegra20/tegra20_slink.h>
+#include <spi.h>
+#include <fdtdec.h>
+
+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);
+}
diff --git a/drivers/spi/tegra20_sflash.c b/drivers/spi/tegra20_sflash.c
index bb1e57d..a4e6c9a 100644
--- a/drivers/spi/tegra20_sflash.c
+++ b/drivers/spi/tegra20_sflash.c
@@ -101,7 +101,7 @@ static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
 	return container_of(slave, struct tegra_spi_slave, slave);
 }
 
-int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+int tegra20_spi_cs_is_valid(unsigned int bus, unsigned int cs)
 {
 	/* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
 	if (bus != 0 || cs != 0)
@@ -110,8 +110,8 @@ int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 		return 1;
 }
 
-struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
-		unsigned int max_hz, unsigned int mode)
+struct spi_slave *tegra20_spi_setup_slave(unsigned int bus, unsigned int cs,
+				  unsigned int max_hz, unsigned int mode)
 {
 	struct tegra_spi_slave *spi;
 
@@ -151,25 +151,20 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	return &spi->slave;
 }
 
-void spi_free_slave(struct spi_slave *slave)
+void tegra20_spi_free_slave(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 
 	free(spi);
 }
 
-void spi_init(void)
+int tegra20_spi_init(int *node_list, int count)
 {
 	struct tegra_spi_ctrl *ctrl;
 	int i;
 	int node = 0;
-	int count;
-	int node_list[1];
+	int found = 0;
 
-	count = fdtdec_find_aliases_for_id(gd->fdt_blob, "spi",
-					   COMPAT_NVIDIA_TEGRA20_SFLASH,
-					   node_list,
-					   1);
 	for (i = 0; i < count; i++) {
 		ctrl = &spi_ctrls[i];
 		node = node_list[i];
@@ -193,13 +188,15 @@ void spi_init(void)
 			continue;
 		}
 		ctrl->valid = 1;
+		found = 1;
 
 		debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
 		      __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
 	}
+	return !found;
 }
 
-int spi_claim_bus(struct spi_slave *slave)
+int tegra20_spi_claim_bus(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -213,7 +210,7 @@ int spi_claim_bus(struct spi_slave *slave)
 	reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
 		SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
 	writel(reg, &regs->status);
-	debug("spi_init: STATUS = %08x\n", readl(&regs->status));
+	debug("%s: STATUS = %08x\n", __func__, readl(&regs->status));
 
 	/*
 	 * Use sw-controlled CS, so we can clock in data after ReadID, etc.
@@ -223,7 +220,7 @@ int spi_claim_bus(struct spi_slave *slave)
 		reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
 	clrsetbits_le32(&regs->command, SPI_CMD_ACTIVE_SCLK_MASK |
 		SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
-	debug("spi_init: COMMAND = %08x\n", readl(&regs->command));
+	debug("%s: COMMAND = %08x\n", __func__, readl(&regs->command));
 
 	/*
 	 * SPI pins on Tegra20 are muxed - change pinmux later due to UART
@@ -236,17 +233,7 @@ int spi_claim_bus(struct spi_slave *slave)
 	return 0;
 }
 
-void spi_release_bus(struct spi_slave *slave)
-{
-	/*
-	 * We can't release UART_DISABLE and set pinmux to UART4 here since
-	 * some code (e,g, spi_flash_probe) uses printf() while the SPI
-	 * bus is held. That is arguably bad, but it has the advantage of
-	 * already being in the source tree.
-	 */
-}
-
-void spi_cs_activate(struct spi_slave *slave)
+void tegra20_spi_cs_activate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -255,7 +242,7 @@ void spi_cs_activate(struct spi_slave *slave)
 	setbits_le32(&regs->command, SPI_CMD_CS_VAL);
 }
 
-void spi_cs_deactivate(struct spi_slave *slave)
+void tegra20_spi_cs_deactivate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -264,7 +251,7 @@ void spi_cs_deactivate(struct spi_slave *slave)
 	clrbits_le32(&regs->command, SPI_CMD_CS_VAL);
 }
 
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+int tegra20_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		const void *data_out, void *data_in, unsigned long flags)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
diff --git a/drivers/spi/tegra20_slink.c b/drivers/spi/tegra20_slink.c
index f3b0964..2ef2eb8 100644
--- a/drivers/spi/tegra20_slink.c
+++ b/drivers/spi/tegra20_slink.c
@@ -107,7 +107,7 @@ static inline struct tegra_spi_slave *to_tegra_spi(struct spi_slave *slave)
 	return container_of(slave, struct tegra_spi_slave, slave);
 }
 
-int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+int tegra30_spi_cs_is_valid(unsigned int bus, unsigned int cs)
 {
 	if (bus >= CONFIG_TEGRA_SLINK_CTRLS || cs > 3 || !spi_ctrls[bus].valid)
 		return 0;
@@ -115,7 +115,7 @@ int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 		return 1;
 }
 
-struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+struct spi_slave *tegra30_spi_setup_slave(unsigned int bus, unsigned int cs,
 		unsigned int max_hz, unsigned int mode)
 {
 	struct tegra_spi_slave *spi;
@@ -159,25 +159,20 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	return &spi->slave;
 }
 
-void spi_free_slave(struct spi_slave *slave)
+void tegra30_spi_free_slave(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 
 	free(spi);
 }
 
-void spi_init(void)
+int tegra30_spi_init(int *node_list, int count)
 {
 	struct tegra_spi_ctrl *ctrl;
 	int i;
 	int node = 0;
-	int count;
-	int node_list[CONFIG_TEGRA_SLINK_CTRLS];
+	int found = 0;
 
-	count = fdtdec_find_aliases_for_id(gd->fdt_blob, "spi",
-					   COMPAT_NVIDIA_TEGRA20_SLINK,
-					   node_list,
-					   CONFIG_TEGRA_SLINK_CTRLS);
 	for (i = 0; i < count; i++) {
 		ctrl = &spi_ctrls[i];
 		node = node_list[i];
@@ -201,13 +196,15 @@ void spi_init(void)
 			continue;
 		}
 		ctrl->valid = 1;
+		found = 1;
 
 		debug("%s: found controller at %p, freq = %u, periph_id = %d\n",
 		      __func__, ctrl->regs, ctrl->freq, ctrl->periph_id);
 	}
+	return !found;
 }
 
-int spi_claim_bus(struct spi_slave *slave)
+int tegra30_spi_claim_bus(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -232,11 +229,7 @@ int spi_claim_bus(struct spi_slave *slave)
 	return 0;
 }
 
-void spi_release_bus(struct spi_slave *slave)
-{
-}
-
-void spi_cs_activate(struct spi_slave *slave)
+void tegra30_spi_cs_activate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -245,7 +238,7 @@ void spi_cs_activate(struct spi_slave *slave)
 	setbits_le32(&regs->command, SLINK_CMD_CS_VAL);
 }
 
-void spi_cs_deactivate(struct spi_slave *slave)
+void tegra30_spi_cs_deactivate(struct spi_slave *slave)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);
 	struct spi_regs *regs = spi->ctrl->regs;
@@ -254,7 +247,7 @@ void spi_cs_deactivate(struct spi_slave *slave)
 	clrbits_le32(&regs->command, SLINK_CMD_CS_VAL);
 }
 
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+int tegra30_spi_xfer(struct spi_slave *slave, unsigned int bitlen,
 		const void *data_out, void *data_in, unsigned long flags)
 {
 	struct tegra_spi_slave *spi = to_tegra_spi(slave);