--- /dev/null
+/* 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");
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff