This patch implements probing for the bus and reporting the number of available expansion slots. Signed-off-by: Sergei Ianovich <ynvich@xxxxxxxxx> --- v3..v4 * move DTS binding to a different patch (8/21) v2..v3 * fixed goto after bus_register * number change (11/16 -> 13/21) v0..v2 * use device tree * use devm helpers where possible .../devicetree/bindings/misc/lp8x4x-bus.txt | 16 ++ Documentation/misc-devices/lp8x4x_bus.txt | 30 ++++ arch/arm/configs/lp8x4x_defconfig | 1 + drivers/misc/Kconfig | 13 ++ drivers/misc/Makefile | 1 + drivers/misc/lp8x4x_bus.c | 167 +++++++++++++++++++++ 6 files changed, 228 insertions(+) create mode 100644 Documentation/devicetree/bindings/misc/lp8x4x-bus.txt create mode 100644 Documentation/misc-devices/lp8x4x_bus.txt create mode 100644 drivers/misc/lp8x4x_bus.c diff --git a/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt b/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt new file mode 100644 index 0000000..1c87a29 --- /dev/null +++ b/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt @@ -0,0 +1,16 @@ +Custom parallel bus on ICP DAS LP-8x4x industrial computers + +See Documentation/misc-devices/lp8x4x_bus.txt for details. + +Required properties: +- compatible : should be "icpdas,backplane-lp8x4x" + +- reg: physical base address of the slot count register and the length + of the memory mapped region. + +Example: + + backplane { + compatible = "icpdas,backplane-lp8x4x"; + reg = <0x17009046 0x2>; + }; diff --git a/Documentation/misc-devices/lp8x4x_bus.txt b/Documentation/misc-devices/lp8x4x_bus.txt new file mode 100644 index 0000000..f5392b3 --- /dev/null +++ b/Documentation/misc-devices/lp8x4x_bus.txt @@ -0,0 +1,30 @@ +Kernel driver lpx8x4x_bus +====================== + +Supported hardare: +Custom parallel bus on ICP DAS LP-8x4x industrial computers + +Data sheet: +Not freely available + +Author: +Sergei Ianovich <ynvich@xxxxxxxxx> + +Description +----------- + +http://www.icpdas.com/root/product/solutions/pac/linpac/lp-8x4x_hardware.html + +LP-8x4x is an ARM-based industrial computer with a custom parallel bus to +connect expansion modules with digital input/output, analog input/output, +serial, CAN and other types of ports. + +The bus is implemented by a FPGA. + +SYSFS +----- + +/sys/bus/icpdas/devices/backplane: + +slot_count + RO - shows total number of expansion slots on the device diff --git a/arch/arm/configs/lp8x4x_defconfig b/arch/arm/configs/lp8x4x_defconfig index 9116ce1..c34eb2a 100644 --- a/arch/arm/configs/lp8x4x_defconfig +++ b/arch/arm/configs/lp8x4x_defconfig @@ -62,6 +62,7 @@ CONFIG_PROC_DEVICETREE=y CONFIG_BLK_DEV_LOOP=y CONFIG_BLK_DEV_LOOP_MIN_COUNT=2 CONFIG_EEPROM_AT24=m +CONFIG_LP8X4X_BUS=m CONFIG_SCSI=y # CONFIG_SCSI_PROC_FS is not set CONFIG_BLK_DEV_SD=y diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 1cb7408..08ffe63 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -515,6 +515,19 @@ config SRAM the genalloc API. It is supposed to be used for small on-chip SRAM areas found on many SoCs. +config LP8X4X_BUS + tristate "ICP DAS LP-8x4x industrial IO bus" + depends on OF && ARCH_PXA + select SYSFS + ---help--- + This is a driver for ICP DAS LP-8x4x programmable automation + controller. It exposes a custom parallel bus. The bus services + data acquisition and control modules. + + Say N, unless you plan to run this kernel on a LP-8x4x system. + + If you say M here, the module will be called lp8x4x_bus. + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 7eb4b69..2bfe25d 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -55,3 +55,4 @@ obj-$(CONFIG_SRAM) += sram.o obj-y += mic/ obj-$(CONFIG_GENWQE) += genwqe/ obj-$(CONFIG_ECHO) += echo/ +obj-$(CONFIG_LP8X4X_BUS) += lp8x4x_bus.o diff --git a/drivers/misc/lp8x4x_bus.c b/drivers/misc/lp8x4x_bus.c new file mode 100644 index 0000000..7aa55cf --- /dev/null +++ b/drivers/misc/lp8x4x_bus.c @@ -0,0 +1,167 @@ +/* + * linux/misc/lp8x4x_bus.c + * + * Support for ICP DAS LP-8x4x programmable automation controller bus + * Copyright (C) 2013 Sergei Ianovich <ynvich@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation or any later version. + */ +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define MODULE_NAME "lp8x4x-bus" +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sergei Ianovich <ynvich@xxxxxxxxx>"); +MODULE_DESCRIPTION("ICP DAS LP-8x4x parallel bus driver"); + +struct lp8x4x_master { + unsigned int slot_count; + void *count_addr; + struct device dev; +}; + +static int lp8x4x_match(struct device *dev, struct device_driver *drv) +{ + return 1; +} + +static struct bus_type lp8x4x_bus_type = { + .name = "icpdas", + .match = lp8x4x_match, +}; + +static void lp8x4x_master_release(struct device *dev) +{ + struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev); + WARN_ON(!dev); + + kfree(m); +} + +static ssize_t slot_count_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev); + + return sprintf(buf, "%u\n", m->slot_count); +} + +static DEVICE_ATTR_RO(slot_count); + +static struct attribute *master_dev_attrs[] = { + &dev_attr_slot_count.attr, + NULL, +}; +ATTRIBUTE_GROUPS(master_dev); + + +static void devm_lp8x4x_bus_release(struct device *dev, void *res) +{ + struct lp8x4x_master *m = *(struct lp8x4x_master **)res; + + dev_dbg(dev, "releasing devices\n"); + device_unregister(&m->dev); + bus_unregister(&lp8x4x_bus_type); +} + +static int __init lp8x4x_bus_probe(struct platform_device *pdev) +{ + struct lp8x4x_master *m, **p; + struct resource *res; + int err = 0; + + m = kzalloc(sizeof(*m), GFP_KERNEL); + if (!m) + return -ENOMEM; + + p = devres_alloc(devm_lp8x4x_bus_release, sizeof(*p), GFP_KERNEL); + if (!p) { + err = -ENOMEM; + goto err1; + } + *p = m; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "could not get slot count address\n"); + err = -ENODEV; + goto err2; + } + + m->count_addr = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(m->count_addr)) { + dev_err(&pdev->dev, "Failed to ioremap slot count address\n"); + err = PTR_ERR(m->count_addr); + goto err2; + } + + m->slot_count = ioread8(m->count_addr); + switch (m->slot_count) { + case 1: + case 4: + break; + case 7: + m->slot_count = 8; + break; + default: + dev_err(&pdev->dev, "unexpected slot number(%u)", + m->slot_count); + err = -ENODEV; + goto err2; + }; + + dev_info(&pdev->dev, "found bus with up to %u slots\n", m->slot_count); + + err = bus_register(&lp8x4x_bus_type); + if (err < 0) { + dev_err(&pdev->dev, "failed to register bus type\n"); + goto err2; + } + + m->dev.bus = &lp8x4x_bus_type; + dev_set_name(&m->dev, "backplane"); + m->dev.parent = &pdev->dev; + m->dev.release = lp8x4x_master_release; + m->dev.groups = master_dev_groups; + + err = device_register(&m->dev); + if (err < 0) { + dev_err(&pdev->dev, "failed to register backplane device\n"); + goto err3; + } + + devres_add(&pdev->dev, p); + return 0; + +err3: + bus_unregister(&lp8x4x_bus_type); +err2: + devres_free(p); +err1: + kfree(m); + return err; +} + +static const struct of_device_id lp8x4x_bus_dt_ids[] = { + { .compatible = "icpdas,backplane-lp8x4x" }, + { } +}; +MODULE_DEVICE_TABLE(of, lp8x4x_bus_dt_ids); + +static struct platform_driver lp8x4x_bus_driver = { + .driver = { + .name = MODULE_NAME, + .owner = THIS_MODULE, + .of_match_table = lp8x4x_bus_dt_ids, + }, +}; + +module_platform_driver_probe(lp8x4x_bus_driver, lp8x4x_bus_probe); -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html