diff options
author | John Ogness <john.ogness@linutronix.de> | 2014-12-09 17:43:10 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-12 05:04:13 -0800 |
commit | fbc4a8a85777e065f7a195ddc58b3245808f1e87 (patch) | |
tree | 8bacc3572b40cb97e6cc1c5295a01d9021ad0c93 /drivers/uio/uio_fsl_elbc_gpcm.c | |
parent | 02b03846bb2befc558bfd0665749d6bb26f4c2f1 (diff) |
uio: uio_fsl_elbc_gpcm: new driver
This driver provides UIO access to memory of a peripheral connected
to the Freescale enhanced local bus controller (eLBC) interface
using the general purpose chip-select mode (GPCM).
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/uio/uio_fsl_elbc_gpcm.c')
-rw-r--r-- | drivers/uio/uio_fsl_elbc_gpcm.c | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/drivers/uio/uio_fsl_elbc_gpcm.c b/drivers/uio/uio_fsl_elbc_gpcm.c new file mode 100644 index 000000000000..b6cac91c2ced --- /dev/null +++ b/drivers/uio/uio_fsl_elbc_gpcm.c @@ -0,0 +1,499 @@ +/* uio_fsl_elbc_gpcm: UIO driver for eLBC/GPCM peripherals + + Copyright (C) 2014 Linutronix GmbH + Author: John Ogness <john.ogness@linutronix.de> + + This driver provides UIO access to memory of a peripheral connected + to the Freescale enhanced local bus controller (eLBC) interface + using the general purpose chip-select mode (GPCM). + + Here is an example of the device tree entries: + + localbus@ffe05000 { + ranges = <0x2 0x0 0x0 0xff810000 0x10000>; + + dpm@2,0 { + compatible = "fsl,elbc-gpcm-uio"; + reg = <0x2 0x0 0x10000>; + elbc-gpcm-br = <0xff810800>; + elbc-gpcm-or = <0xffff09f7>; + interrupt-parent = <&mpic>; + interrupts = <4 1>; + device_type = "netx5152"; + uio_name = "netx_custom"; + netx5152,init-win0-offset = <0x0>; + }; + }; + + Only the entries reg (to identify bank) and elbc-gpcm-* (initial BR/OR + values) are required. The entries interrupt*, device_type, and uio_name + are optional (as well as any type-specific options such as + netx5152,init-win0-offset). As long as no interrupt handler is needed, + this driver can be used without any type-specific implementation. + + The netx5152 type has been tested to work with the netX 51/52 hardware + from Hilscher using the Hilscher userspace netX stack. + + The netx5152 type should serve as a model to add new type-specific + devices as needed. +*/ + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/uio_driver.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/fsl_lbc.h> + +#define MAX_BANKS 8 + +struct fsl_elbc_gpcm { + struct device *dev; + struct fsl_lbc_regs __iomem *lbc; + u32 bank; + const char *name; + + void (*init)(struct uio_info *info); + void (*shutdown)(struct uio_info *info, bool init_err); + irqreturn_t (*irq_handler)(int irq, struct uio_info *info); +}; + +static ssize_t reg_show(struct device *dev, struct device_attribute *attr, + char *buf); +static ssize_t reg_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count); + +DEVICE_ATTR(reg_br, S_IRUGO|S_IWUSR|S_IWGRP, reg_show, reg_store); +DEVICE_ATTR(reg_or, S_IRUGO|S_IWUSR|S_IWGRP, reg_show, reg_store); + +static ssize_t reg_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uio_info *info = platform_get_drvdata(pdev); + struct fsl_elbc_gpcm *priv = info->priv; + struct fsl_lbc_bank *bank = &priv->lbc->bank[priv->bank]; + + if (attr == &dev_attr_reg_br) { + return scnprintf(buf, PAGE_SIZE, "0x%08x\n", + in_be32(&bank->br)); + + } else if (attr == &dev_attr_reg_or) { + return scnprintf(buf, PAGE_SIZE, "0x%08x\n", + in_be32(&bank->or)); + } + + return 0; +} + +static ssize_t reg_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uio_info *info = platform_get_drvdata(pdev); + struct fsl_elbc_gpcm *priv = info->priv; + struct fsl_lbc_bank *bank = &priv->lbc->bank[priv->bank]; + unsigned long val; + u32 reg_br_cur; + u32 reg_or_cur; + u32 reg_new; + + /* parse use input */ + if (kstrtoul(buf, 0, &val) != 0) + return -EINVAL; + reg_new = (u32)val; + + /* read current values */ + reg_br_cur = in_be32(&bank->br); + reg_or_cur = in_be32(&bank->or); + + if (attr == &dev_attr_reg_br) { + /* not allowed to change effective base address */ + if ((reg_br_cur & reg_or_cur & BR_BA) != + (reg_new & reg_or_cur & BR_BA)) { + return -EINVAL; + } + + /* not allowed to change mode */ + if ((reg_new & BR_MSEL) != BR_MS_GPCM) + return -EINVAL; + + /* write new value (force valid) */ + out_be32(&bank->br, reg_new | BR_V); + + } else if (attr == &dev_attr_reg_or) { + /* not allowed to change access mask */ + if ((reg_or_cur & OR_GPCM_AM) != (reg_new & OR_GPCM_AM)) + return -EINVAL; + + /* write new value */ + out_be32(&bank->or, reg_new); + + } else { + return -EINVAL; + } + + return count; +} + +#ifdef CONFIG_UIO_FSL_ELBC_GPCM_NETX5152 +#define DPM_HOST_WIN0_OFFSET 0xff00 +#define DPM_HOST_INT_STAT0 0xe0 +#define DPM_HOST_INT_EN0 0xf0 +#define DPM_HOST_INT_MASK 0xe600ffff +#define DPM_HOST_INT_GLOBAL_EN 0x80000000 + +static irqreturn_t netx5152_irq_handler(int irq, struct uio_info *info) +{ + void __iomem *reg_int_en = info->mem[0].internal_addr + + DPM_HOST_WIN0_OFFSET + + DPM_HOST_INT_EN0; + void __iomem *reg_int_stat = info->mem[0].internal_addr + + DPM_HOST_WIN0_OFFSET + + DPM_HOST_INT_STAT0; + + /* check if an interrupt is enabled and active */ + if ((ioread32(reg_int_en) & ioread32(reg_int_stat) & + DPM_HOST_INT_MASK) == 0) { + return IRQ_NONE; + } + + /* disable interrupts */ + iowrite32(ioread32(reg_int_en) & ~DPM_HOST_INT_GLOBAL_EN, reg_int_en); + + return IRQ_HANDLED; +} + +static void netx5152_init(struct uio_info *info) +{ + unsigned long win0_offset = DPM_HOST_WIN0_OFFSET; + struct fsl_elbc_gpcm *priv = info->priv; + const void *prop; + + /* get an optional initial win0 offset */ + prop = of_get_property(priv->dev->of_node, + "netx5152,init-win0-offset", NULL); + if (prop) + win0_offset = of_read_ulong(prop, 1); + + /* disable interrupts */ + iowrite32(0, info->mem[0].internal_addr + win0_offset + + DPM_HOST_INT_EN0); +} + +static void netx5152_shutdown(struct uio_info *info, bool init_err) +{ + if (init_err) + return; + + /* disable interrupts */ + iowrite32(0, info->mem[0].internal_addr + DPM_HOST_WIN0_OFFSET + + DPM_HOST_INT_EN0); +} +#endif + +static void setup_periph(struct fsl_elbc_gpcm *priv, + const char *type) +{ +#ifdef CONFIG_UIO_FSL_ELBC_GPCM_NETX5152 + if (strcmp(type, "netx5152") == 0) { + priv->irq_handler = netx5152_irq_handler; + priv->init = netx5152_init; + priv->shutdown = netx5152_shutdown; + priv->name = "netX 51/52"; + return; + } +#endif +} + +static int check_of_data(struct fsl_elbc_gpcm *priv, + struct resource *res, + u32 reg_br, u32 reg_or) +{ + /* check specified bank */ + if (priv->bank >= MAX_BANKS) { + dev_err(priv->dev, "invalid bank\n"); + return -ENODEV; + } + + /* check specified mode (BR_MS_GPCM is 0) */ + if ((reg_br & BR_MSEL) != BR_MS_GPCM) { + dev_err(priv->dev, "unsupported mode\n"); + return -ENODEV; + } + + /* check specified mask vs. resource size */ + if ((~(reg_or & OR_GPCM_AM) + 1) != resource_size(res)) { + dev_err(priv->dev, "address mask / size mismatch\n"); + return -ENODEV; + } + + /* check specified address */ + if ((reg_br & reg_or & BR_BA) != fsl_lbc_addr(res->start)) { + dev_err(priv->dev, "base address mismatch\n"); + return -ENODEV; + } + + return 0; +} + +static int get_of_data(struct fsl_elbc_gpcm *priv, struct device_node *node, + struct resource *res, u32 *reg_br, + u32 *reg_or, unsigned int *irq, char **name) +{ + const char *dt_name; + const char *type; + int ret; + + /* get the memory resource */ + ret = of_address_to_resource(node, 0, res); + if (ret) { + dev_err(priv->dev, "failed to get resource\n"); + return ret; + } + + /* get the bank number */ + ret = of_property_read_u32(node, "reg", &priv->bank); + if (ret) { + dev_err(priv->dev, "failed to get bank number\n"); + return ret; + } + + /* get BR value to set */ + ret = of_property_read_u32(node, "elbc-gpcm-br", reg_br); + if (ret) { + dev_err(priv->dev, "missing elbc-gpcm-br value\n"); + return ret; + } + + /* get OR value to set */ + ret = of_property_read_u32(node, "elbc-gpcm-or", reg_or); + if (ret) { + dev_err(priv->dev, "missing elbc-gpcm-or value\n"); + return ret; + } + + /* get optional peripheral type */ + priv->name = "generic"; + if (of_property_read_string(node, "device_type", &type) == 0) + setup_periph(priv, type); + + /* get optional irq value */ + *irq = irq_of_parse_and_map(node, 0); + + /* sanity check device tree data */ + ret = check_of_data(priv, res, *reg_br, *reg_or); + if (ret) + return ret; + + /* get optional uio name */ + if (of_property_read_string(node, "uio_name", &dt_name) != 0) + dt_name = "eLBC_GPCM"; + *name = kstrdup(dt_name, GFP_KERNEL); + if (!*name) + return -ENOMEM; + + return 0; +} + +static int uio_fsl_elbc_gpcm_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct fsl_elbc_gpcm *priv; + struct uio_info *info; + char *uio_name = NULL; + struct resource res; + unsigned int irq; + u32 reg_br_cur; + u32 reg_or_cur; + u32 reg_br_new; + u32 reg_or_new; + int ret; + + if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs) + return -ENODEV; + + /* allocate private data */ + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + priv->dev = &pdev->dev; + priv->lbc = fsl_lbc_ctrl_dev->regs; + + /* get device tree data */ + ret = get_of_data(priv, node, &res, ®_br_new, ®_or_new, + &irq, &uio_name); + if (ret) + goto out_err0; + + /* allocate UIO structure */ + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto out_err0; + } + + /* get current BR/OR values */ + reg_br_cur = in_be32(&priv->lbc->bank[priv->bank].br); + reg_or_cur = in_be32(&priv->lbc->bank[priv->bank].or); + + /* if bank already configured, make sure it matches */ + if ((reg_br_cur & BR_V)) { + if ((reg_br_cur & BR_MSEL) != BR_MS_GPCM || + (reg_br_cur & reg_or_cur & BR_BA) + != fsl_lbc_addr(res.start)) { + dev_err(priv->dev, + "bank in use by another peripheral\n"); + ret = -ENODEV; + goto out_err1; + } + + /* warn if behavior settings changing */ + if ((reg_br_cur & ~(BR_BA | BR_V)) != + (reg_br_new & ~(BR_BA | BR_V))) { + dev_warn(priv->dev, + "modifying BR settings: 0x%08x -> 0x%08x", + reg_br_cur, reg_br_new); + } + if ((reg_or_cur & ~OR_GPCM_AM) != (reg_or_new & ~OR_GPCM_AM)) { + dev_warn(priv->dev, + "modifying OR settings: 0x%08x -> 0x%08x", + reg_or_cur, reg_or_new); + } + } + + /* configure the bank (force base address and GPCM) */ + reg_br_new &= ~(BR_BA | BR_MSEL); + reg_br_new |= fsl_lbc_addr(res.start) | BR_MS_GPCM | BR_V; + out_be32(&priv->lbc->bank[priv->bank].or, reg_or_new); + out_be32(&priv->lbc->bank[priv->bank].br, reg_br_new); + + /* map the memory resource */ + info->mem[0].internal_addr = ioremap(res.start, resource_size(&res)); + if (!info->mem[0].internal_addr) { + dev_err(priv->dev, "failed to map chip region\n"); + ret = -ENODEV; + goto out_err1; + } + + /* set all UIO data */ + if (node->name) + info->mem[0].name = kstrdup(node->name, GFP_KERNEL); + info->mem[0].addr = res.start; + info->mem[0].size = resource_size(&res); + info->mem[0].memtype = UIO_MEM_PHYS; + info->priv = priv; + info->name = uio_name; + info->version = "0.0.1"; + if (irq != NO_IRQ) { + if (priv->irq_handler) { + info->irq = irq; + info->irq_flags = IRQF_SHARED; + info->handler = priv->irq_handler; + } else { + irq = NO_IRQ; + dev_warn(priv->dev, "ignoring irq, no handler\n"); + } + } + + if (priv->init) + priv->init(info); + + /* register UIO device */ + if (uio_register_device(priv->dev, info) != 0) { + dev_err(priv->dev, "UIO registration failed\n"); + ret = -ENODEV; + goto out_err2; + } + + /* store private data */ + platform_set_drvdata(pdev, info); + + /* create sysfs files */ + ret = device_create_file(priv->dev, &dev_attr_reg_br); + if (ret) + goto out_err3; + ret = device_create_file(priv->dev, &dev_attr_reg_or); + if (ret) + goto out_err4; + + dev_info(priv->dev, + "eLBC/GPCM device (%s) at 0x%llx, bank %d, irq=%d\n", + priv->name, (unsigned long long)res.start, priv->bank, + irq != NO_IRQ ? irq : -1); + + return 0; +out_err4: + device_remove_file(priv->dev, &dev_attr_reg_br); +out_err3: + platform_set_drvdata(pdev, NULL); + uio_unregister_device(info); +out_err2: + if (priv->shutdown) + priv->shutdown(info, true); + iounmap(info->mem[0].internal_addr); +out_err1: + kfree(info->mem[0].name); + kfree(info); +out_err0: + kfree(uio_name); + kfree(priv); + return ret; +} + +static int uio_fsl_elbc_gpcm_remove(struct platform_device *pdev) +{ + struct uio_info *info = platform_get_drvdata(pdev); + struct fsl_elbc_gpcm *priv = info->priv; + + device_remove_file(priv->dev, &dev_attr_reg_or); + device_remove_file(priv->dev, &dev_attr_reg_br); + platform_set_drvdata(pdev, NULL); + uio_unregister_device(info); + if (priv->shutdown) + priv->shutdown(info, false); + iounmap(info->mem[0].internal_addr); + kfree(info->mem[0].name); + kfree(info->name); + kfree(info); + kfree(priv); + + return 0; + +} + +static const struct of_device_id uio_fsl_elbc_gpcm_match[] = { + { .compatible = "fsl,elbc-gpcm-uio", }, + {} +}; + +static struct platform_driver uio_fsl_elbc_gpcm_driver = { + .driver = { + .name = "fsl,elbc-gpcm-uio", + .owner = THIS_MODULE, + .of_match_table = uio_fsl_elbc_gpcm_match, + }, + .probe = uio_fsl_elbc_gpcm_probe, + .remove = uio_fsl_elbc_gpcm_remove, +}; + +static int __init uio_fsl_elbc_gpcm_init(void) +{ + return platform_driver_register(&uio_fsl_elbc_gpcm_driver); +} + +static void __exit uio_fsl_elbc_gpcm_exit(void) +{ + platform_driver_unregister(&uio_fsl_elbc_gpcm_driver); +} + +module_init(uio_fsl_elbc_gpcm_init); +module_exit(uio_fsl_elbc_gpcm_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>"); +MODULE_DESCRIPTION("Freescale Enhanced Local Bus Controller GPCM driver"); |