diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/misc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/misc/vexpress-syscfg.c | 324 |
3 files changed, 334 insertions, 0 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 8baff0effc7d..d9663ef90ce8 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -515,6 +515,15 @@ config SRAM the genalloc API. It is supposed to be used for small on-chip SRAM areas found on many SoCs. +config VEXPRESS_SYSCFG + bool "Versatile Express System Configuration driver" + depends on VEXPRESS_CONFIG + default y + help + ARM Ltd. Versatile Express uses specialised platform configuration + bus. System Configuration interface is one of the possible means + of generating transactions on this 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 7eb4b69580c0..d59ce1261b38 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_VEXPRESS_SYSCFG) += vexpress-syscfg.o diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c new file mode 100644 index 000000000000..73068e50e56d --- /dev/null +++ b/drivers/misc/vexpress-syscfg.c @@ -0,0 +1,324 @@ +/* + * 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. + * + * 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. + * + * Copyright (C) 2014 ARM Limited + */ + +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/syscore_ops.h> +#include <linux/vexpress.h> + + +#define SYS_CFGDATA 0x0 + +#define SYS_CFGCTRL 0x4 +#define SYS_CFGCTRL_START (1 << 31) +#define SYS_CFGCTRL_WRITE (1 << 30) +#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26) +#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20) +#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16) +#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12) +#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0) + +#define SYS_CFGSTAT 0x8 +#define SYS_CFGSTAT_ERR (1 << 1) +#define SYS_CFGSTAT_COMPLETE (1 << 0) + + +struct vexpress_syscfg { + struct device *dev; + void __iomem *base; + struct list_head funcs; +}; + +struct vexpress_syscfg_func { + struct list_head list; + struct vexpress_syscfg *syscfg; + struct regmap *regmap; + int num_templates; + u32 template[0]; /* Keep it last! */ +}; + + +static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func, + int index, bool write, u32 *data) +{ + struct vexpress_syscfg *syscfg = func->syscfg; + u32 command, status; + int tries; + long timeout; + + if (WARN_ON(index > func->num_templates)) + return -EINVAL; + + command = readl(syscfg->base + SYS_CFGCTRL); + if (WARN_ON(command & SYS_CFGCTRL_START)) + return -EBUSY; + + command = func->template[index]; + command |= SYS_CFGCTRL_START; + command |= write ? SYS_CFGCTRL_WRITE : 0; + + /* Use a canary for reads */ + if (!write) + *data = 0xdeadbeef; + + dev_dbg(syscfg->dev, "func %p, command %x, data %x\n", + func, command, *data); + writel(*data, syscfg->base + SYS_CFGDATA); + writel(0, syscfg->base + SYS_CFGSTAT); + writel(command, syscfg->base + SYS_CFGCTRL); + mb(); + + /* The operation can take ages... Go to sleep, 100us initially */ + tries = 100; + timeout = 100; + do { + if (!irqs_disabled()) { + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(usecs_to_jiffies(timeout)); + if (signal_pending(current)) + return -EINTR; + } else { + udelay(timeout); + } + + status = readl(syscfg->base + SYS_CFGSTAT); + if (status & SYS_CFGSTAT_ERR) + return -EFAULT; + + if (timeout > 20) + timeout -= 20; + } while (--tries && !(status & SYS_CFGSTAT_COMPLETE)); + if (WARN_ON_ONCE(!tries)) + return -ETIMEDOUT; + + if (!write) { + *data = readl(syscfg->base + SYS_CFGDATA); + dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data); + } + + return 0; +} + +static int vexpress_syscfg_read(void *context, unsigned int index, + unsigned int *val) +{ + struct vexpress_syscfg_func *func = context; + + return vexpress_syscfg_exec(func, index, false, val); +} + +static int vexpress_syscfg_write(void *context, unsigned int index, + unsigned int val) +{ + struct vexpress_syscfg_func *func = context; + + return vexpress_syscfg_exec(func, index, true, &val); +} + +struct regmap_config vexpress_syscfg_regmap_config = { + .lock = vexpress_config_lock, + .unlock = vexpress_config_unlock, + .reg_bits = 32, + .val_bits = 32, + .reg_read = vexpress_syscfg_read, + .reg_write = vexpress_syscfg_write, + .reg_format_endian = REGMAP_ENDIAN_LITTLE, + .val_format_endian = REGMAP_ENDIAN_LITTLE, +}; + + +static struct regmap *vexpress_syscfg_regmap_init(struct device *dev, + void *context) +{ + struct platform_device *pdev = to_platform_device(dev); + struct vexpress_syscfg *syscfg = context; + struct vexpress_syscfg_func *func; + struct property *prop; + const __be32 *val = NULL; + __be32 energy_quirk[4]; + int num; + u32 site, position, dcc; + int i; + + if (dev->of_node) { + int err = vexpress_config_get_topo(dev->of_node, &site, + &position, &dcc); + + if (err) + return ERR_PTR(err); + + prop = of_find_property(dev->of_node, + "arm,vexpress-sysreg,func", NULL); + if (!prop) + return ERR_PTR(-EINVAL); + + num = prop->length / sizeof(u32) / 2; + val = prop->value; + } else { + if (pdev->num_resources != 1 || + pdev->resource[0].flags != IORESOURCE_BUS) + return ERR_PTR(-EFAULT); + + site = pdev->resource[0].start; + if (site == VEXPRESS_SITE_MASTER) + site = vexpress_config_get_master(); + position = 0; + dcc = 0; + num = 1; + } + + /* + * "arm,vexpress-energy" function used to be described + * by its first device only, now it requires both + */ + if (num == 1 && of_device_is_compatible(dev->of_node, + "arm,vexpress-energy")) { + num = 2; + energy_quirk[0] = *val; + energy_quirk[2] = *val++; + energy_quirk[1] = *val; + energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1); + val = energy_quirk; + } + + func = kzalloc(sizeof(*func) + sizeof(*func->template) * num, + GFP_KERNEL); + if (!func) + return NULL; + + func->syscfg = syscfg; + func->num_templates = num; + + for (i = 0; i < num; i++) { + u32 function, device; + + if (dev->of_node) { + function = be32_to_cpup(val++); + device = be32_to_cpup(val++); + } else { + function = pdev->resource[0].end; + device = pdev->id; + } + + dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n", + func, site, position, dcc, + function, device); + + func->template[i] = SYS_CFGCTRL_DCC(dcc); + func->template[i] |= SYS_CFGCTRL_SITE(site); + func->template[i] |= SYS_CFGCTRL_POSITION(position); + func->template[i] |= SYS_CFGCTRL_FUNC(function); + func->template[i] |= SYS_CFGCTRL_DEVICE(device); + } + + vexpress_syscfg_regmap_config.max_register = num - 1; + + func->regmap = regmap_init(dev, NULL, func, + &vexpress_syscfg_regmap_config); + + if (IS_ERR(func->regmap)) + kfree(func); + else + list_add(&func->list, &syscfg->funcs); + + return func->regmap; +} + +static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context) +{ + struct vexpress_syscfg *syscfg = context; + struct vexpress_syscfg_func *func, *tmp; + + regmap_exit(regmap); + + list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) { + if (func->regmap == regmap) { + list_del(&syscfg->funcs); + kfree(func); + break; + } + } +} + +static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = { + .regmap_init = vexpress_syscfg_regmap_init, + .regmap_exit = vexpress_syscfg_regmap_exit, +}; + + +/* Non-DT hack, to be gone... */ +static struct device *vexpress_syscfg_bridge; + +int vexpress_syscfg_device_register(struct platform_device *pdev) +{ + pdev->dev.parent = vexpress_syscfg_bridge; + + return platform_device_register(pdev); +} + + +int vexpress_syscfg_probe(struct platform_device *pdev) +{ + struct vexpress_syscfg *syscfg; + struct resource *res; + struct device *bridge; + + syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL); + if (!syscfg) + return -ENOMEM; + syscfg->dev = &pdev->dev; + INIT_LIST_HEAD(&syscfg->funcs); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!devm_request_mem_region(&pdev->dev, res->start, + resource_size(res), pdev->name)) + return -EBUSY; + + syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!syscfg->base) + return -EFAULT; + + /* Must use dev.parent (MFD), as that's where DT phandle points at... */ + bridge = vexpress_config_bridge_register(pdev->dev.parent, + &vexpress_syscfg_bridge_ops, syscfg); + if (IS_ERR(bridge)) + return PTR_ERR(bridge); + + /* Non-DT case */ + if (!pdev->dev.of_node) + vexpress_syscfg_bridge = bridge; + + return 0; +} + +static const struct platform_device_id vexpress_syscfg_id_table[] = { + { "vexpress-syscfg", }, + {}, +}; + +static struct platform_driver vexpress_syscfg_driver = { + .driver.name = "vexpress-syscfg", + .id_table = vexpress_syscfg_id_table, + .probe = vexpress_syscfg_probe, +}; + +static int __init vexpress_syscfg_init(void) +{ + return platform_driver_register(&vexpress_syscfg_driver); +} +core_initcall(vexpress_syscfg_init); |