[PATCH v9 0/2] memory: add Atmel EBI (External Bus Interface) driver

[PATCH v9 0/2] memory: add Atmel EBI (External Bus Interface) driver

[Boris Brezillon]

Hello,

This patch series provides support for the EBI bus.

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.

Best Regards,

Boris

Changes since v8:
- fixed typo in DT bindings doc

Changes since v7:
- move EBI bus config properties directly in the sub-device node
- prefix all EBI/SMC properties with atmel,smc-
- rework the driver to take the new binding into account
- disable the subdevice when EBI implementation fails to configure
  the bus as requested

Changes since v6:
- rework the binding to put per-device config information into a
  separate subnode and have devices connected to the EBI bus
  defined as direct children of the EBI node
- make all EBI timings mandatory
- keep adding sub-devices when a failure occurs on one of them

Changes since v5:
- remove the "atmel,specialized-logic" property: now all devices are
  are attached to the SMC logic by default, and specialized drivers
  (like the NAND controller one), should change this configuration
  manually.
- provide hardware readout to allow partial config description.
  This is mainly here to keep existing platforms (where everything
  is configured by the bootloader/bootstrap) in working state.
- rename "atmel,tdf-optimized" into "atmel,tdf-mode" and switch from
  a boolean to string property to properly support partial config

Changes since v4:
- fix inconsistencies in SMC and MATRIX registers definition
- add missing compatible strings for at91sam9rl SoC
- fix DT bindings documentation
- replace "atmel,generic-dev" property by "atmel,specialized-logic"

Changes since v3:
- added AT91_MATRIX_USBPUCR_PUON definition
- removed useless macros (those directly returning SoC specific register
  offsets)
- use syscon_regmap_lookup_by_phandle instead of of_parse_phandle +
  syscon_node_to_regmap
- drop AT91_EBICSA_REGFIELD and AT91_MULTI_EBICSA_REGFIELD macros

Changes since v2:
- minor fixes int DT bindings doc
- fix SMC macros
- make use of SMC macros defined in include/linux/mfd/syscon/atmel-smc.h

Changes since v1:
- almost everything :-)

Boris Brezillon (2):
  memory: add Atmel EBI (External Bus Interface) driver
  memory: atmel-ebi: add DT bindings documentation

 .../bindings/memory-controllers/atmel,ebi.txt      | 136 ++++
 drivers/memory/Kconfig                             |  11 +
 drivers/memory/Makefile                            |   1 +
 drivers/memory/atmel-ebi.c                         | 771 +++++++++++++++++++++
 4 files changed, 919 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt
 create mode 100644 drivers/memory/atmel-ebi.c

-- 
2.7.4

[PATCH v9 1/2] memory: add Atmel EBI (External Bus Interface) driver

[Boris Brezillon]

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-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/memory/Kconfig     |  11 +
 drivers/memory/Makefile    |   1 +
 drivers/memory/atmel-ebi.c | 771 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 783 insertions(+)
 create mode 100644 drivers/memory/atmel-ebi.c

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index c61a284..d13ce16 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 cb0b7a1..b20ae38 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 0000000..712c767
--- /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 JJ Hiblot.
+ *
+ * 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("JJ Hiblot");
+MODULE_DESCRIPTION("Atmel EBI driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

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[PATCH v9 2/2] memory: atmel-ebi: add DT bindings documentation

[Boris Brezillon]

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>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../bindings/memory-controllers/atmel,ebi.txt      | 136 +++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt b/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt
new file mode 100644
index 0000000..9bb5f57
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt
@@ -0,0 +1,136 @@
+* Device tree bindings for Atmel EBI
+
+The External Bus Interface (EBI) controller is a bus where you can connect
+asynchronous (NAND, NOR, SRAM, ....) and synchronous memories (SDR/DDR SDRAMs).
+The EBI provides a glue-less interface to asynchronous memories through the SMC
+(Static Memory Controller).
+
+Required properties:
+
+- compatible:		"atmel,at91sam9260-ebi"
+			"atmel,at91sam9261-ebi"
+			"atmel,at91sam9263-ebi0"
+			"atmel,at91sam9263-ebi1"
+			"atmel,at91sam9rl-ebi"
+			"atmel,at91sam9g45-ebi"
+			"atmel,at91sam9x5-ebi"
+			"atmel,sama5d3-ebi"
+
+- reg:			Contains offset/length value for EBI memory mapping.
+			This property might contain several entries if the EBI
+			memory range is not contiguous
+
+- #address-cells:	Must be 2.
+			The first cell encodes the CS.
+			The second cell encode the offset into the CS memory
+			range.
+
+- #size-cells:		Must be set to 1.
+
+- ranges:		Encodes CS to memory region association.
+
+- clocks:		Clock feeding the EBI controller.
+			See clock-bindings.txt
+
+Children device nodes are representing device connected to the EBI bus.
+
+Required device node properties:
+
+- reg:			Contains the chip-select id, the offset and the length
+			of the memory region requested by the device.
+
+EBI bus configuration will be defined directly in the device subnode.
+
+Optional EBI/SMC properties:
+
+- atmel,smc-bus-width:		width of the asynchronous device's data bus
+				8, 16 or 32.
+				Default to 8 when undefined.
+
+- atmel,smc-byte-access-type	"write" or "select" (see Atmel datasheet).
+				Default to "select" when undefined.
+
+- atmel,smc-read-mode		"nrd" or "ncs".
+				Default to "ncs" when undefined.
+
+- atmel,smc-write-mode		"nwe" or "ncs".
+				Default to "ncs" when undefined.
+
+- atmel,smc-exnw-mode		"disabled", "frozen" or "ready".
+				Default to "disabled" when undefined.
+
+- atmel,smc-page-mode		enable page mode if present. The provided value
+				defines the page size (supported values: 4, 8,
+				16 and 32).
+
+- atmel,smc-tdf-mode:		"normal" or "optimized". When set to
+				"optimized" the data float time is optimized
+				depending on the next device being accessed
+				(next device setup time is subtracted to the
+				current device data float time).
+				Default to "normal" when undefined.
+
+If at least one atmel,smc- property is defined the following SMC timing
+properties become mandatory. In the other hand, if none of the atmel,smc-
+properties are specified, we assume that the EBI bus configuration will be
+handled by the sub-device driver, and none of those properties should be
+defined.
+
+All the timings are expressed in nanoseconds (see Atmel datasheet for a full
+description).
+
+- atmel,smc-ncs-rd-setup-ns
+- atmel,smc-nrd-setup-ns
+- atmel,smc-ncs-wr-setup-ns
+- atmel,smc-nwe-setup-ns
+- atmel,smc-ncs-rd-pulse-ns
+- atmel,smc-nrd-pulse-ns
+- atmel,smc-ncs-wr-pulse-ns
+- atmel,smc-nwe-pulse-ns
+- atmel,smc-nwe-cycle-ns
+- atmel,smc-nrd-cycle-ns
+- atmel,smc-tdf-ns
+
+Example:
+
+	ebi: ebi@10000000 {
+		compatible = "atmel,sama5d3-ebi";
+		#address-cells = <2>;
+		#size-cells = <1>;
+		atmel,smc = <&hsmc>;
+		atmel,matrix = <&matrix>;
+		reg = <0x10000000 0x10000000
+		       0x40000000 0x30000000>;
+		ranges = <0x0 0x0 0x10000000 0x10000000
+			  0x1 0x0 0x40000000 0x10000000
+			  0x2 0x0 0x50000000 0x10000000
+			  0x3 0x0 0x60000000 0x10000000>;
+		clocks = <&mck>;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_ebi_addr>;
+
+		nor: flash@0,0 {
+			compatible = "cfi-flash";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			reg = <0x0 0x0 0x1000000>;
+			bank-width = <2>;
+
+			atmel,smc-read-mode = "nrd";
+			atmel,smc-write-mode = "nwe";
+			atmel,smc-bus-width = <16>;
+			atmel,smc-ncs-rd-setup-ns = <0>;
+			atmel,smc-ncs-wr-setup-ns = <0>;
+			atmel,smc-nwe-setup-ns = <8>;
+			atmel,smc-nrd-setup-ns = <16>;
+			atmel,smc-ncs-rd-pulse-ns = <84>;
+			atmel,smc-ncs-wr-pulse-ns = <84>;
+			atmel,smc-nrd-pulse-ns = <76>;
+			atmel,smc-nwe-pulse-ns = <76>;
+			atmel,smc-nrd-cycle-ns = <107>;
+			atmel,smc-nwe-cycle-ns = <84>;
+			atmel,smc-tdf-ns = <16>;
+		};
+	};
+
-- 
2.7.4

Re: [PATCH v9 0/2] memory: add Atmel EBI (External Bus Interface) driver

[Alexandre Belloni]

On 23/05/2016 at 09:44:53 +0200, Boris Brezillon wrote :
> Hello,
> 
> This patch series provides support for the EBI bus.
> 
> 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.
> 
> Best Regards,
> 
> Boris
> 
> Changes since v8:
> - fixed typo in DT bindings doc
> 
> Changes since v7:
> - move EBI bus config properties directly in the sub-device node
> - prefix all EBI/SMC properties with atmel,smc-
> - rework the driver to take the new binding into account
> - disable the subdevice when EBI implementation fails to configure
>   the bus as requested
> 
> Changes since v6:
> - rework the binding to put per-device config information into a
>   separate subnode and have devices connected to the EBI bus
>   defined as direct children of the EBI node
> - make all EBI timings mandatory
> - keep adding sub-devices when a failure occurs on one of them
> 
> Changes since v5:
> - remove the "atmel,specialized-logic" property: now all devices are
>   are attached to the SMC logic by default, and specialized drivers
>   (like the NAND controller one), should change this configuration
>   manually.
> - provide hardware readout to allow partial config description.
>   This is mainly here to keep existing platforms (where everything
>   is configured by the bootloader/bootstrap) in working state.
> - rename "atmel,tdf-optimized" into "atmel,tdf-mode" and switch from
>   a boolean to string property to properly support partial config
> 
> Changes since v4:
> - fix inconsistencies in SMC and MATRIX registers definition
> - add missing compatible strings for at91sam9rl SoC
> - fix DT bindings documentation
> - replace "atmel,generic-dev" property by "atmel,specialized-logic"
> 
> Changes since v3:
> - added AT91_MATRIX_USBPUCR_PUON definition
> - removed useless macros (those directly returning SoC specific register
>   offsets)
> - use syscon_regmap_lookup_by_phandle instead of of_parse_phandle +
>   syscon_node_to_regmap
> - drop AT91_EBICSA_REGFIELD and AT91_MULTI_EBICSA_REGFIELD macros
> 
> Changes since v2:
> - minor fixes int DT bindings doc
> - fix SMC macros
> - make use of SMC macros defined in include/linux/mfd/syscon/atmel-smc.h
> 
> Changes since v1:
> - almost everything :-)
> 
> Boris Brezillon (2):
>   memory: add Atmel EBI (External Bus Interface) driver
>   memory: atmel-ebi: add DT bindings documentation
> 
Applied, thanks.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com