memory: add Atmel EBI (External Bus Interface) driver

The EBI (External Bus Interface) is used to access external peripherals
(NOR, SRAM, NAND, and other specific devices like ethernet controllers).
Each device is assigned a CS line and an address range and can have its
own configuration (timings, access mode, bus width, ...).
This driver provides a generic DT binding to configure a device according
to its requirements.
For specific device controllers (like the NAND one) the SMC timings
should be configured by the controller driver through the matrix and
smc syscon regmaps.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

3 files changed, 783 insertions, 0 deletions

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 81ddb17575a9..133712346911 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -25,6 +25,17 @@ config ATMEL_SDRAMC
 	  Starting with the at91sam9g45, this controller supports SDR, DDR and
 	  LP-DDR memories.
 
+config ATMEL_EBI
+	bool "Atmel EBI driver"
+	default y
+	depends on ARCH_AT91 && OF
+	select MFD_SYSCON
+	help
+	  Driver for Atmel EBI controller.
+	  Used to configure the EBI (external bus interface) when the device-
+	  tree is used. This bus supports NANDs, external ethernet controller,
+	  SRAMs, ATA devices, etc.
+
 config TI_AEMIF
 	tristate "Texas Instruments AEMIF driver"
 	depends on (ARCH_DAVINCI || ARCH_KEYSTONE) && OF
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index cb0b7a1df11a..b20ae38b5bfb 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_OF)		+= of_memory.o
 endif
 obj-$(CONFIG_ARM_PL172_MPMC)	+= pl172.o
 obj-$(CONFIG_ATMEL_SDRAMC)	+= atmel-sdramc.o
+obj-$(CONFIG_ATMEL_EBI)		+= atmel-ebi.o
 obj-$(CONFIG_TI_AEMIF)		+= ti-aemif.o
 obj-$(CONFIG_TI_EMIF)		+= emif.o
 obj-$(CONFIG_OMAP_GPMC)		+= omap-gpmc.o
diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
new file mode 100644
index 000000000000..17d9d3f60f20
--- /dev/null
+++ b/drivers/memory/atmel-ebi.c
@@ -0,0 +1,771 @@
+/*
+ * EBI driver for Atmel chips
+ * inspired by the fsl weim bus driver
+ *
+ * Copyright (C) 2013 Jean-Jacques Hiblot <jjhiblot@traphandler.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-matrix.h>
+#include <linux/mfd/syscon/atmel-smc.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+struct at91sam9_smc_timings {
+	u32 ncs_rd_setup_ns;
+	u32 nrd_setup_ns;
+	u32 ncs_wr_setup_ns;
+	u32 nwe_setup_ns;
+	u32 ncs_rd_pulse_ns;
+	u32 nrd_pulse_ns;
+	u32 ncs_wr_pulse_ns;
+	u32 nwe_pulse_ns;
+	u32 nrd_cycle_ns;
+	u32 nwe_cycle_ns;
+	u32 tdf_ns;
+};
+
+struct at91sam9_smc_generic_fields {
+	struct regmap_field *setup;
+	struct regmap_field *pulse;
+	struct regmap_field *cycle;
+	struct regmap_field *mode;
+};
+
+struct at91sam9_ebi_dev_config {
+	struct at91sam9_smc_timings timings;
+	u32 mode;
+};
+
+struct at91_ebi_dev_config {
+	int cs;
+	union {
+		struct at91sam9_ebi_dev_config sam9;
+	};
+};
+
+struct at91_ebi;
+
+struct at91_ebi_dev {
+	struct list_head node;
+	struct at91_ebi *ebi;
+	u32 mode;
+	int numcs;
+	struct at91_ebi_dev_config configs[];
+};
+
+struct at91_ebi_caps {
+	unsigned int available_cs;
+	const struct reg_field *ebi_csa;
+	void (*get_config)(struct at91_ebi_dev *ebid,
+			   struct at91_ebi_dev_config *conf);
+	int (*xlate_config)(struct at91_ebi_dev *ebid,
+			    struct device_node *configs_np,
+			    struct at91_ebi_dev_config *conf);
+	int (*apply_config)(struct at91_ebi_dev *ebid,
+			    struct at91_ebi_dev_config *conf);
+	int (*init)(struct at91_ebi *ebi);
+};
+
+struct at91_ebi {
+	struct clk *clk;
+	struct regmap *smc;
+	struct regmap *matrix;
+
+	struct regmap_field *ebi_csa;
+
+	struct device *dev;
+	const struct at91_ebi_caps *caps;
+	struct list_head devs;
+	union {
+		struct at91sam9_smc_generic_fields sam9;
+	};
+};
+
+static void at91sam9_ebi_get_config(struct at91_ebi_dev *ebid,
+				    struct at91_ebi_dev_config *conf)
+{
+	struct at91sam9_smc_generic_fields *fields = &ebid->ebi->sam9;
+	unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
+	struct at91sam9_ebi_dev_config *config = &conf->sam9;
+	struct at91sam9_smc_timings *timings = &config->timings;
+	unsigned int val;
+
+	regmap_fields_read(fields->mode, conf->cs, &val);
+	config->mode = val & ~AT91_SMC_TDF;
+
+	val = (val & AT91_SMC_TDF) >> 16;
+	timings->tdf_ns = clk_rate * val;
+
+	regmap_fields_read(fields->setup, conf->cs, &val);
+	timings->ncs_rd_setup_ns = (val >> 24) & 0x1f;
+	timings->ncs_rd_setup_ns += ((val >> 29) & 0x1) * 128;
+	timings->ncs_rd_setup_ns *= clk_rate;
+	timings->nrd_setup_ns = (val >> 16) & 0x1f;
+	timings->nrd_setup_ns += ((val >> 21) & 0x1) * 128;
+	timings->nrd_setup_ns *= clk_rate;
+	timings->ncs_wr_setup_ns = (val >> 8) & 0x1f;
+	timings->ncs_wr_setup_ns += ((val >> 13) & 0x1) * 128;
+	timings->ncs_wr_setup_ns *= clk_rate;
+	timings->nwe_setup_ns = val & 0x1f;
+	timings->nwe_setup_ns += ((val >> 5) & 0x1) * 128;
+	timings->nwe_setup_ns *= clk_rate;
+
+	regmap_fields_read(fields->pulse, conf->cs, &val);
+	timings->ncs_rd_pulse_ns = (val >> 24) & 0x3f;
+	timings->ncs_rd_pulse_ns += ((val >> 30) & 0x1) * 256;
+	timings->ncs_rd_pulse_ns *= clk_rate;
+	timings->nrd_pulse_ns = (val >> 16) & 0x3f;
+	timings->nrd_pulse_ns += ((val >> 22) & 0x1) * 256;
+	timings->nrd_pulse_ns *= clk_rate;
+	timings->ncs_wr_pulse_ns = (val >> 8) & 0x3f;
+	timings->ncs_wr_pulse_ns += ((val >> 14) & 0x1) * 256;
+	timings->ncs_wr_pulse_ns *= clk_rate;
+	timings->nwe_pulse_ns = val & 0x3f;
+	timings->nwe_pulse_ns += ((val >> 6) & 0x1) * 256;
+	timings->nwe_pulse_ns *= clk_rate;
+
+	regmap_fields_read(fields->cycle, conf->cs, &val);
+	timings->nrd_cycle_ns = (val >> 16) & 0x7f;
+	timings->nrd_cycle_ns += ((val >> 23) & 0x3) * 256;
+	timings->nrd_cycle_ns *= clk_rate;
+	timings->nwe_cycle_ns = val & 0x7f;
+	timings->nwe_cycle_ns += ((val >> 7) & 0x3) * 256;
+	timings->nwe_cycle_ns *= clk_rate;
+}
+
+static int at91_xlate_timing(struct device_node *np, const char *prop,
+			     u32 *val, bool *required)
+{
+	if (!of_property_read_u32(np, prop, val)) {
+		*required = true;
+		return 0;
+	}
+
+	if (*required)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int at91sam9_smc_xslate_timings(struct at91_ebi_dev *ebid,
+				       struct device_node *np,
+				       struct at91sam9_smc_timings *timings,
+				       bool *required)
+{
+	int ret;
+
+	ret = at91_xlate_timing(np, "atmel,smc-ncs-rd-setup-ns",
+				&timings->ncs_rd_setup_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nrd-setup-ns",
+				&timings->nrd_setup_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-ncs-wr-setup-ns",
+				&timings->ncs_wr_setup_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nwe-setup-ns",
+				&timings->nwe_setup_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-ncs-rd-pulse-ns",
+				&timings->ncs_rd_pulse_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nrd-pulse-ns",
+				&timings->nrd_pulse_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-ncs-wr-pulse-ns",
+				&timings->ncs_wr_pulse_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nwe-pulse-ns",
+				&timings->nwe_pulse_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nwe-cycle-ns",
+				&timings->nwe_cycle_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-nrd-cycle-ns",
+				&timings->nrd_cycle_ns, required);
+	if (ret)
+		goto out;
+
+	ret = at91_xlate_timing(np, "atmel,smc-tdf-ns",
+				&timings->tdf_ns, required);
+
+out:
+	if (ret)
+		dev_err(ebid->ebi->dev,
+			"missing or invalid timings definition in %s",
+			np->full_name);
+
+	return ret;
+}
+
+static int at91sam9_ebi_xslate_config(struct at91_ebi_dev *ebid,
+				      struct device_node *np,
+				      struct at91_ebi_dev_config *conf)
+{
+	struct at91sam9_ebi_dev_config *config = &conf->sam9;
+	bool required = false;
+	const char *tmp_str;
+	u32 tmp;
+	int ret;
+
+	ret = of_property_read_u32(np, "atmel,smc-bus-width", &tmp);
+	if (!ret) {
+		switch (tmp) {
+		case 8:
+			config->mode |= AT91_SMC_DBW_8;
+			break;
+
+		case 16:
+			config->mode |= AT91_SMC_DBW_16;
+			break;
+
+		case 32:
+			config->mode |= AT91_SMC_DBW_32;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+
+		required = true;
+	}
+
+	if (of_property_read_bool(np, "atmel,smc-tdf-optimized")) {
+		config->mode |= AT91_SMC_TDFMODE_OPTIMIZED;
+		required = true;
+	}
+
+	tmp_str = NULL;
+	of_property_read_string(np, "atmel,smc-byte-access-type", &tmp_str);
+	if (tmp_str && !strcmp(tmp_str, "write")) {
+		config->mode |= AT91_SMC_BAT_WRITE;
+		required = true;
+	}
+
+	tmp_str = NULL;
+	of_property_read_string(np, "atmel,smc-read-mode", &tmp_str);
+	if (tmp_str && !strcmp(tmp_str, "nrd")) {
+		config->mode |= AT91_SMC_READMODE_NRD;
+		required = true;
+	}
+
+	tmp_str = NULL;
+	of_property_read_string(np, "atmel,smc-write-mode", &tmp_str);
+	if (tmp_str && !strcmp(tmp_str, "nwe")) {
+		config->mode |= AT91_SMC_WRITEMODE_NWE;
+		required = true;
+	}
+
+	tmp_str = NULL;
+	of_property_read_string(np, "atmel,smc-exnw-mode", &tmp_str);
+	if (tmp_str) {
+		if (!strcmp(tmp_str, "frozen"))
+			config->mode |= AT91_SMC_EXNWMODE_FROZEN;
+		else if (!strcmp(tmp_str, "ready"))
+			config->mode |= AT91_SMC_EXNWMODE_READY;
+		else if (strcmp(tmp_str, "disabled"))
+			return -EINVAL;
+
+		required = true;
+	}
+
+	ret = of_property_read_u32(np, "atmel,smc-page-mode", &tmp);
+	if (!ret) {
+		switch (tmp) {
+		case 4:
+			config->mode |= AT91_SMC_PS_4;
+			break;
+
+		case 8:
+			config->mode |= AT91_SMC_PS_8;
+			break;
+
+		case 16:
+			config->mode |= AT91_SMC_PS_16;
+			break;
+
+		case 32:
+			config->mode |= AT91_SMC_PS_32;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+
+		config->mode |= AT91_SMC_PMEN;
+		required = true;
+	}
+
+	ret = at91sam9_smc_xslate_timings(ebid, np, &config->timings,
+					  &required);
+	if (ret)
+		return ret;
+
+	return required;
+}
+
+static int at91sam9_ebi_apply_config(struct at91_ebi_dev *ebid,
+				     struct at91_ebi_dev_config *conf)
+{
+	unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
+	struct at91sam9_ebi_dev_config *config = &conf->sam9;
+	struct at91sam9_smc_timings *timings = &config->timings;
+	struct at91sam9_smc_generic_fields *fields = &ebid->ebi->sam9;
+	u32 coded_val;
+	u32 val;
+
+	coded_val = at91sam9_smc_setup_ns_to_cycles(clk_rate,
+						    timings->ncs_rd_setup_ns);
+	val = AT91SAM9_SMC_NCS_NRDSETUP(coded_val);
+	coded_val = at91sam9_smc_setup_ns_to_cycles(clk_rate,
+						    timings->nrd_setup_ns);
+	val |= AT91SAM9_SMC_NRDSETUP(coded_val);
+	coded_val = at91sam9_smc_setup_ns_to_cycles(clk_rate,
+						    timings->ncs_wr_setup_ns);
+	val |= AT91SAM9_SMC_NCS_WRSETUP(coded_val);
+	coded_val = at91sam9_smc_setup_ns_to_cycles(clk_rate,
+						    timings->nwe_setup_ns);
+	val |= AT91SAM9_SMC_NWESETUP(coded_val);
+	regmap_fields_write(fields->setup, conf->cs, val);
+
+	coded_val = at91sam9_smc_pulse_ns_to_cycles(clk_rate,
+						    timings->ncs_rd_pulse_ns);
+	val = AT91SAM9_SMC_NCS_NRDPULSE(coded_val);
+	coded_val = at91sam9_smc_pulse_ns_to_cycles(clk_rate,
+						    timings->nrd_pulse_ns);
+	val |= AT91SAM9_SMC_NRDPULSE(coded_val);
+	coded_val = at91sam9_smc_pulse_ns_to_cycles(clk_rate,
+						    timings->ncs_wr_pulse_ns);
+	val |= AT91SAM9_SMC_NCS_WRPULSE(coded_val);
+	coded_val = at91sam9_smc_pulse_ns_to_cycles(clk_rate,
+						    timings->nwe_pulse_ns);
+	val |= AT91SAM9_SMC_NWEPULSE(coded_val);
+	regmap_fields_write(fields->pulse, conf->cs, val);
+
+	coded_val = at91sam9_smc_cycle_ns_to_cycles(clk_rate,
+						    timings->nrd_cycle_ns);
+	val = AT91SAM9_SMC_NRDCYCLE(coded_val);
+	coded_val = at91sam9_smc_cycle_ns_to_cycles(clk_rate,
+						    timings->nwe_cycle_ns);
+	val |= AT91SAM9_SMC_NWECYCLE(coded_val);
+	regmap_fields_write(fields->cycle, conf->cs, val);
+
+	val = DIV_ROUND_UP(timings->tdf_ns, clk_rate);
+	if (val > AT91_SMC_TDF_MAX)
+		val = AT91_SMC_TDF_MAX;
+	regmap_fields_write(fields->mode, conf->cs,
+			    config->mode | AT91_SMC_TDF_(val));
+
+	return 0;
+}
+
+static int at91sam9_ebi_init(struct at91_ebi *ebi)
+{
+	struct at91sam9_smc_generic_fields *fields = &ebi->sam9;
+	struct reg_field field = REG_FIELD(0, 0, 31);
+
+	field.id_size = fls(ebi->caps->available_cs);
+	field.id_offset = AT91SAM9_SMC_GENERIC_BLK_SZ;
+
+	field.reg = AT91SAM9_SMC_SETUP(AT91SAM9_SMC_GENERIC);
+	fields->setup = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->setup))
+		return PTR_ERR(fields->setup);
+
+	field.reg = AT91SAM9_SMC_PULSE(AT91SAM9_SMC_GENERIC);
+	fields->pulse = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->pulse))
+		return PTR_ERR(fields->pulse);
+
+	field.reg = AT91SAM9_SMC_CYCLE(AT91SAM9_SMC_GENERIC);
+	fields->cycle = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->cycle))
+		return PTR_ERR(fields->cycle);
+
+	field.reg = AT91SAM9_SMC_MODE(AT91SAM9_SMC_GENERIC);
+	fields->mode = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->mode))
+		return PTR_ERR(fields->mode);
+
+	return 0;
+}
+
+static int sama5d3_ebi_init(struct at91_ebi *ebi)
+{
+	struct at91sam9_smc_generic_fields *fields = &ebi->sam9;
+	struct reg_field field = REG_FIELD(0, 0, 31);
+
+	field.id_size = fls(ebi->caps->available_cs);
+	field.id_offset = SAMA5_SMC_GENERIC_BLK_SZ;
+
+	field.reg = AT91SAM9_SMC_SETUP(SAMA5_SMC_GENERIC);
+	fields->setup = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->setup))
+		return PTR_ERR(fields->setup);
+
+	field.reg = AT91SAM9_SMC_PULSE(SAMA5_SMC_GENERIC);
+	fields->pulse = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->pulse))
+		return PTR_ERR(fields->pulse);
+
+	field.reg = AT91SAM9_SMC_CYCLE(SAMA5_SMC_GENERIC);
+	fields->cycle = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->cycle))
+		return PTR_ERR(fields->cycle);
+
+	field.reg = SAMA5_SMC_MODE(SAMA5_SMC_GENERIC);
+	fields->mode = devm_regmap_field_alloc(ebi->dev, ebi->smc, field);
+	if (IS_ERR(fields->mode))
+		return PTR_ERR(fields->mode);
+
+	return 0;
+}
+
+static int at91_ebi_dev_setup(struct at91_ebi *ebi, struct device_node *np,
+			      int reg_cells)
+{
+	const struct at91_ebi_caps *caps = ebi->caps;
+	struct at91_ebi_dev_config conf = { };
+	struct device *dev = ebi->dev;
+	struct at91_ebi_dev *ebid;
+	int ret, numcs = 0, i;
+	bool apply = false;
+
+	numcs = of_property_count_elems_of_size(np, "reg",
+						reg_cells * sizeof(u32));
+	if (numcs <= 0) {
+		dev_err(dev, "invalid reg property in %s\n", np->full_name);
+		return -EINVAL;
+	}
+
+	ebid = devm_kzalloc(ebi->dev,
+			    sizeof(*ebid) + (numcs * sizeof(*ebid->configs)),
+			    GFP_KERNEL);
+	if (!ebid)
+		return -ENOMEM;
+
+	ebid->ebi = ebi;
+
+	ret = caps->xlate_config(ebid, np, &conf);
+	if (ret < 0)
+		return ret;
+	else if (ret)
+		apply = true;
+
+	for (i = 0; i < numcs; i++) {
+		u32 cs;
+
+		ret = of_property_read_u32_index(np, "reg", i * reg_cells,
+						 &cs);
+		if (ret)
+			return ret;
+
+		if (cs > AT91_MATRIX_EBI_NUM_CS ||
+		    !(ebi->caps->available_cs & BIT(cs))) {
+			dev_err(dev, "invalid reg property in %s\n",
+				np->full_name);
+			return -EINVAL;
+		}
+
+		ebid->configs[i].cs = cs;
+
+		if (apply) {
+			conf.cs = cs;
+			ret = caps->apply_config(ebid, &conf);
+			if (ret)
+				return ret;
+		}
+
+		caps->get_config(ebid, &ebid->configs[i]);
+
+		/*
+		 * Attach the EBI device to the generic SMC logic if at least
+		 * one "atmel,smc-" property is present.
+		 */
+		if (ebi->ebi_csa && ret)
+			regmap_field_update_bits(ebi->ebi_csa,
+						 BIT(cs), 0);
+	}
+
+	list_add_tail(&ebid->node, &ebi->devs);
+
+	return 0;
+}
+
+static const struct reg_field at91sam9260_ebi_csa =
+				REG_FIELD(AT91SAM9260_MATRIX_EBICSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9260_ebi_caps = {
+	.available_cs = 0xff,
+	.ebi_csa = &at91sam9260_ebi_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct reg_field at91sam9261_ebi_csa =
+				REG_FIELD(AT91SAM9261_MATRIX_EBICSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9261_ebi_caps = {
+	.available_cs = 0xff,
+	.ebi_csa = &at91sam9261_ebi_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct reg_field at91sam9263_ebi0_csa =
+				REG_FIELD(AT91SAM9263_MATRIX_EBI0CSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9263_ebi0_caps = {
+	.available_cs = 0x3f,
+	.ebi_csa = &at91sam9263_ebi0_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct reg_field at91sam9263_ebi1_csa =
+				REG_FIELD(AT91SAM9263_MATRIX_EBI1CSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9263_ebi1_caps = {
+	.available_cs = 0x7,
+	.ebi_csa = &at91sam9263_ebi1_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct reg_field at91sam9rl_ebi_csa =
+				REG_FIELD(AT91SAM9RL_MATRIX_EBICSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9rl_ebi_caps = {
+	.available_cs = 0x3f,
+	.ebi_csa = &at91sam9rl_ebi_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct reg_field at91sam9g45_ebi_csa =
+				REG_FIELD(AT91SAM9G45_MATRIX_EBICSA, 0,
+					  AT91_MATRIX_EBI_NUM_CS - 1);
+
+static const struct at91_ebi_caps at91sam9g45_ebi_caps = {
+	.available_cs = 0x3f,
+	.ebi_csa = &at91sam9g45_ebi_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct at91_ebi_caps at91sam9x5_ebi_caps = {
+	.available_cs = 0x3f,
+	.ebi_csa = &at91sam9263_ebi0_csa,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = at91sam9_ebi_init,
+};
+
+static const struct at91_ebi_caps sama5d3_ebi_caps = {
+	.available_cs = 0xf,
+	.get_config = at91sam9_ebi_get_config,
+	.xlate_config = at91sam9_ebi_xslate_config,
+	.apply_config = at91sam9_ebi_apply_config,
+	.init = sama5d3_ebi_init,
+};
+
+static const struct of_device_id at91_ebi_id_table[] = {
+	{
+		.compatible = "atmel,at91sam9260-ebi",
+		.data = &at91sam9260_ebi_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9261-ebi",
+		.data = &at91sam9261_ebi_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9263-ebi0",
+		.data = &at91sam9263_ebi0_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9263-ebi1",
+		.data = &at91sam9263_ebi1_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9rl-ebi",
+		.data = &at91sam9rl_ebi_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9g45-ebi",
+		.data = &at91sam9g45_ebi_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9x5-ebi",
+		.data = &at91sam9x5_ebi_caps,
+	},
+	{
+		.compatible = "atmel,sama5d3-ebi",
+		.data = &sama5d3_ebi_caps,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, at91_ebi_id_table);
+
+static int at91_ebi_dev_disable(struct at91_ebi *ebi, struct device_node *np)
+{
+	struct device *dev = ebi->dev;
+	struct property *newprop;
+
+	newprop = devm_kzalloc(dev, sizeof(*newprop), GFP_KERNEL);
+	if (!newprop)
+		return -ENOMEM;
+
+	newprop->name = devm_kstrdup(dev, "status", GFP_KERNEL);
+	if (!newprop->name)
+		return -ENOMEM;
+
+	newprop->value = devm_kstrdup(dev, "disabled", GFP_KERNEL);
+	if (!newprop->name)
+		return -ENOMEM;
+
+	newprop->length = sizeof("disabled");
+
+	return of_update_property(np, newprop);
+}
+
+static int at91_ebi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *child, *np = dev->of_node;
+	const struct of_device_id *match;
+	struct at91_ebi *ebi;
+	int ret, reg_cells;
+	struct clk *clk;
+	u32 val;
+
+	match = of_match_device(at91_ebi_id_table, dev);
+	if (!match || !match->data)
+		return -EINVAL;
+
+	ebi = devm_kzalloc(dev, sizeof(*ebi), GFP_KERNEL);
+	if (!ebi)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&ebi->devs);
+	ebi->caps = match->data;
+	ebi->dev = dev;
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	ebi->clk = clk;
+
+	ebi->smc = syscon_regmap_lookup_by_phandle(np, "atmel,smc");
+	if (IS_ERR(ebi->smc))
+		return PTR_ERR(ebi->smc);
+
+	/*
+	 * The sama5d3 does not provide an EBICSA register and thus does need
+	 * to access the matrix registers.
+	 */
+	if (ebi->caps->ebi_csa) {
+		ebi->matrix =
+			syscon_regmap_lookup_by_phandle(np, "atmel,matrix");
+		if (IS_ERR(ebi->matrix))
+			return PTR_ERR(ebi->matrix);
+
+		ebi->ebi_csa = regmap_field_alloc(ebi->matrix,
+						  *ebi->caps->ebi_csa);
+		if (IS_ERR(ebi->ebi_csa))
+			return PTR_ERR(ebi->ebi_csa);
+	}
+
+	ret = ebi->caps->init(ebi);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_u32(np, "#address-cells", &val);
+	if (ret) {
+		dev_err(dev, "missing #address-cells property\n");
+		return ret;
+	}
+
+	reg_cells = val;
+
+	ret = of_property_read_u32(np, "#size-cells", &val);
+	if (ret) {
+		dev_err(dev, "missing #address-cells property\n");
+		return ret;
+	}
+
+	reg_cells += val;
+
+	for_each_available_child_of_node(np, child) {
+		if (!of_find_property(child, "reg", NULL))
+			continue;
+
+		ret = at91_ebi_dev_setup(ebi, child, reg_cells);
+		if (ret) {
+			dev_err(dev, "failed to configure EBI bus for %s, disabling the device",
+				child->full_name);
+
+			ret = at91_ebi_dev_disable(ebi, child);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return of_platform_populate(np, NULL, NULL, dev);
+}
+
+static struct platform_driver at91_ebi_driver = {
+	.driver = {
+		.name = "atmel-ebi",
+		.of_match_table	= at91_ebi_id_table,
+	},
+};
+module_platform_driver_probe(at91_ebi_driver, at91_ebi_probe);
+
+MODULE_AUTHOR("Jean-Jacques Hiblot <jjhiblot@traphandler.com>");
+MODULE_DESCRIPTION("Atmel EBI driver");
+MODULE_LICENSE("GPL");