Hi Alan, I saw that your socfpga driver doesn't support the partial reconfig use case (not a big deal). What I currently do for Zynq is if I'm doing a non-partial reconfig is that I disable input level shifters and assert *all* resets while reprogramming in my FPGA manager .write_init() and .write_complete(). For a partial reconfig use case that obviously doesn't work, since I don't want to bring down the entire interconnect. In a partial reconfiguration situation, would I have separate simple-fpga buses for each of the parts that I swap out, each with it's own reset and bitfile attached? On Fri, Jul 17, 2015 at 8:51 AM, <atull@xxxxxxxxxxxxxxxxxxxxx> wrote: > From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > > Add simple fpga bus. This is a bus that configures an fpga and its > bridges before populating the devices below it. This is intended > for use with device tree overlays. > > Note that FPGA bridges are seen as reset controllers so no special > framework for FPGA bridges will need to be added. > > This supports fpga use where hardware blocks on a fpga will need > drivers (as opposed to fpga used as an acceleration without drivers.) > > Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > --- > drivers/staging/fpga/Kconfig | 11 ++ > drivers/staging/fpga/Makefile | 1 + > drivers/staging/fpga/simple-fpga-bus.c | 323 ++++++++++++++++++++++++++++++++ > 3 files changed, 335 insertions(+) > create mode 100644 drivers/staging/fpga/simple-fpga-bus.c > > diff --git a/drivers/staging/fpga/Kconfig b/drivers/staging/fpga/Kconfig > index 8254ca0..8d003e3 100644 > --- a/drivers/staging/fpga/Kconfig > +++ b/drivers/staging/fpga/Kconfig > @@ -11,4 +11,15 @@ config FPGA > kernel. The FPGA framework adds a FPGA manager class and FPGA > manager drivers. > > +if FPGA > + > +config SIMPLE_FPGA_BUS > + bool "Simple FPGA Bus" > + depends on OF > + help > + Simple FPGA Bus allows loading FPGA images under control of > + Device Tree. > + > +endif # FPGA > + > endmenu > diff --git a/drivers/staging/fpga/Makefile b/drivers/staging/fpga/Makefile > index 3313c52..6115213 100644 > --- a/drivers/staging/fpga/Makefile > +++ b/drivers/staging/fpga/Makefile > @@ -4,5 +4,6 @@ > > # Core FPGA Manager Framework > obj-$(CONFIG_FPGA) += fpga-mgr.o > +obj-$(CONFIG_SIMPLE_FPGA_BUS) += simple-fpga-bus.o > > # FPGA Manager Drivers > diff --git a/drivers/staging/fpga/simple-fpga-bus.c b/drivers/staging/fpga/simple-fpga-bus.c > new file mode 100644 > index 0000000..bf178d8 > --- /dev/null > +++ b/drivers/staging/fpga/simple-fpga-bus.c > @@ -0,0 +1,323 @@ > +/* > + * Simple FPGA Bus > + * > + * Copyright (C) 2013-2015 Altera Corporation > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/fpga/fpga-mgr.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_platform.h> > +#include <linux/reset.h> > +#include <linux/slab.h> > + > +/** > + * struct simple_fpga_bus - simple fpga bus private data > + * @dev: device from pdev > + * @mgr: the fpga manager associated with this bus > + * @bridges: an array of reset controls for controlling FPGA bridges > + * associated with this bus > + * @num_bridges: size of the bridges array > + */ > +struct simple_fpga_bus { > + struct device *dev; > + struct fpga_manager *mgr; > + struct reset_control **bridges; > + int num_bridges; > +}; > + > +/** > + * simple_fpga_bus_get_mgr - get associated fpga manager > + * @priv: simple fpga bus private data > + * pointer to fpga manager in priv->mgr on success > + * > + * Given a simple fpga bus, get a reference to its the fpga manager specified > + * by its "fpga-mgr" device tree property. > + * > + * Return: 0 if success or if the fpga manager is not specified. > + * Negative error code otherwise. > + */ > +static int simple_fpga_bus_get_mgr(struct simple_fpga_bus *priv) > +{ > + struct device *dev = priv->dev; > + struct device_node *np = dev->of_node; > + struct fpga_manager *mgr; > + struct device_node *mgr_node; > + > + /* > + * Return 0 (not an error) if fpga manager is not specified. > + * This supports the case where fpga was already configured. > + */ > + mgr_node = of_parse_phandle(np, "fpga-mgr", 0); > + if (!mgr_node) { > + dev_dbg(dev, "could not find fpga-mgr DT property\n"); > + return 0; > + } > + > + mgr = of_fpga_mgr_get(mgr_node); > + if (IS_ERR(mgr)) > + return PTR_ERR(mgr); > + > + priv->mgr = mgr; > + > + return 0; > +} > + > +/** > + * simple_fpga_bus_load_image - load an fpga image under device tree control > + * @priv: simple fpga bus private data > + * > + * Given a simple fpga bus, load the fpga image specified in its device > + * tree node. > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +static int simple_fpga_bus_load_image(struct simple_fpga_bus *priv) > +{ > + struct device *dev = priv->dev; > + struct device_node *np = dev->of_node; > + struct fpga_manager *mgr = priv->mgr; > + u32 flags = 0; > + const char *path; > + > + if (of_property_read_bool(np, "partial-reconfig")) > + flags |= FPGA_MGR_PARTIAL_RECONFIG; > + > + /* If firmware image is specified in the DT, load it */ > + if (!of_property_read_string(np, "fpga-firmware", &path)) > + return fpga_mgr_firmware_load(mgr, flags, path); > + > + /* > + * Here we can add other methods of getting ahold of a fpga image > + * specified in the device tree and programming it. > + */ > + > + dev_info(dev, "No FPGA image to load.\n"); > + > + /* Status is that we have a fpga manager but no image specified. */ > + return -EINVAL; > +} > + > +/** > + * simple_fpga_bus_bridge_enable - enable the fpga bridges > + * @priv: simple fpga bus private data > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +static int simple_fpga_bus_bridge_enable(struct simple_fpga_bus *priv) > +{ > + int i, ret; > + > + for (i = 0; i < priv->num_bridges; i++) { > + ret = reset_control_deassert(priv->bridges[i]); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +/** > + * simple_fpga_bus_bridge_disable - disable the bridges > + * @priv: simple fpga bus private data > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +static int simple_fpga_bus_bridge_disable(struct simple_fpga_bus *priv) > +{ > + int i, ret; > + > + for (i = 0; i < priv->num_bridges; i++) { > + ret = reset_control_assert(priv->bridges[i]); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +/** > + * simple_fpga_bus_get_bridges - get references for fpga bridges > + * @priv: simple fpga bus private data > + * > + * Given a simple fpga bus, get references for its associated fpga bridges so > + * that it can enable/disable the bridges. These are specified by "resets" > + * and "reset-names" device tree properties. > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +static int simple_fpga_bus_get_bridges(struct simple_fpga_bus *priv) > +{ > + struct device *dev = priv->dev; > + struct device_node *np = dev->of_node; > + const char *reset_name; > + struct reset_control **bridges; > + int i, num_resets, num_names, ret; > + > + num_resets = of_count_phandle_with_args(np, "resets", "#reset-cells"); > + num_names = of_property_count_strings(np, "reset-names"); > + if (num_resets <= 0 || num_names <= 0) { > + dev_info(dev, "No fpga bridge resets found\n"); > + return -EINVAL; > + } > + if (num_resets != num_names) { > + dev_dbg(dev, "Number of resets and reset-names differ."); > + return -EINVAL; > + } > + > + bridges = kcalloc(num_resets, sizeof(struct reset_control *), > + GFP_KERNEL); > + if (!bridges) > + return -ENOMEM; > + > + for (i = 0; i < num_resets; i++) { > + ret = of_property_read_string_index(np, "reset-names", i, > + &reset_name); > + if (ret) > + return ret; > + > + bridges[i] = of_reset_control_get(np, reset_name); > + if (IS_ERR(bridges[i])) { > + ret = PTR_ERR(bridges[i]); > + goto err_free_bridges; > + } > + } > + > + priv->bridges = bridges; > + priv->num_bridges = num_resets; > + > + return 0; > + > +err_free_bridges: > + for (i = 0; i < num_resets; i++) > + reset_control_put(priv->bridges[i]); > + > + kfree(bridges); > + return ret; > +} > + > +/** > + * simple_fpga_bus_put_bridges - release references for the fpga bridges > + * @priv: simple fpga bus private data > + */ > +static void simple_fpga_bus_put_bridges(struct simple_fpga_bus *priv) > +{ > + int i; > + > + for (i = 0; i < priv->num_bridges; i++) > + reset_control_put(priv->bridges[i]); > + > + kfree(priv->bridges); > + priv->num_bridges = 0; > +} > + > +/** > + * simple_fpga_bus_probe - Probe function for simple fpga bus. > + * @pdev: platform device > + * > + * Do the necessary steps to program the FPGA and enable associated bridges. > + * Then populate the device tree below this bus to get drivers probed for the > + * hardware that is on the FPGA. > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +static int simple_fpga_bus_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct simple_fpga_bus *priv; > + int ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->dev = dev; > + > + ret = simple_fpga_bus_get_mgr(priv); > + if (ret) > + return ret; > + > + if (priv->mgr) { > + ret = simple_fpga_bus_get_bridges(priv); See below. > + if (ret) > + goto err_release_mgr; > + > + ret = simple_fpga_bus_load_image(priv); > + if (ret) > + goto err_release_br; > + > + ret = simple_fpga_bus_bridge_enable(priv); In my tests I never saw an actual disable happen. This might be a bug in my reset controller driver, if that's the case please ignore my nit ;-) But wouldn't you want to assert while reconfiguring? > + if (ret) > + goto err_release_br; > + } > + > + of_platform_populate(np, of_default_bus_match_table, NULL, dev); > + > + platform_set_drvdata(pdev, priv); > + > + return 0; > + > +err_release_br: > + simple_fpga_bus_put_bridges(priv); > +err_release_mgr: > + fpga_mgr_put(priv->mgr); > + > + return ret; > +} > + > +static int simple_fpga_bus_remove(struct platform_device *pdev) > +{ > + struct simple_fpga_bus *priv = platform_get_drvdata(pdev); > + > + simple_fpga_bus_bridge_disable(priv); > + simple_fpga_bus_put_bridges(priv); > + fpga_mgr_put(priv->mgr); > + > + return 0; > +} > + > +static const struct of_device_id simple_fpga_bus_of_match[] = { > + { .compatible = "simple-fpga-bus", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, simple_fpga_bus_of_match); > + > +static struct platform_driver simple_fpga_bus_driver = { > + .probe = simple_fpga_bus_probe, > + .remove = simple_fpga_bus_remove, > + .driver = { > + .name = "simple-fpga-bus", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(simple_fpga_bus_of_match), > + }, > +}; > + > +static int __init simple_fpga_bus_init(void) > +{ > + return platform_driver_register(&simple_fpga_bus_driver); > +} > + > +static void __exit simple_fpga_bus_exit(void) > +{ > + platform_driver_unregister(&simple_fpga_bus_driver); > +} > + > +module_init(simple_fpga_bus_init); > +module_exit(simple_fpga_bus_exit); > + > +MODULE_DESCRIPTION("Simple FPGA Bus"); > +MODULE_AUTHOR("Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > -- > 1.7.9.5 > > _______________________________________________ > devel mailing list > devel@xxxxxxxxxxxxxxxxxxxxxx > http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel Cheers, Moritz -- 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
