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225 lines
5.1 KiB
225 lines
5.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* OPAL Operator Panel Display Driver |
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* |
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* Copyright 2016, Suraj Jitindar Singh, IBM Corporation. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/fs.h> |
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#include <linux/device.h> |
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#include <linux/errno.h> |
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#include <linux/mutex.h> |
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#include <linux/of.h> |
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#include <linux/slab.h> |
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#include <linux/platform_device.h> |
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#include <linux/miscdevice.h> |
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#include <asm/opal.h> |
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/* |
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* This driver creates a character device (/dev/op_panel) which exposes the |
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* operator panel (character LCD display) on IBM Power Systems machines |
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* with FSPs. |
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* A character buffer written to the device will be displayed on the |
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* operator panel. |
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*/ |
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static DEFINE_MUTEX(oppanel_mutex); |
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static u32 num_lines, oppanel_size; |
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static oppanel_line_t *oppanel_lines; |
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static char *oppanel_data; |
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static loff_t oppanel_llseek(struct file *filp, loff_t offset, int whence) |
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{ |
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return fixed_size_llseek(filp, offset, whence, oppanel_size); |
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} |
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static ssize_t oppanel_read(struct file *filp, char __user *userbuf, size_t len, |
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loff_t *f_pos) |
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{ |
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return simple_read_from_buffer(userbuf, len, f_pos, oppanel_data, |
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oppanel_size); |
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} |
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static int __op_panel_update_display(void) |
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{ |
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struct opal_msg msg; |
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int rc, token; |
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token = opal_async_get_token_interruptible(); |
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if (token < 0) { |
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if (token != -ERESTARTSYS) |
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pr_debug("Couldn't get OPAL async token [token=%d]\n", |
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token); |
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return token; |
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} |
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rc = opal_write_oppanel_async(token, oppanel_lines, num_lines); |
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switch (rc) { |
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case OPAL_ASYNC_COMPLETION: |
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rc = opal_async_wait_response(token, &msg); |
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if (rc) { |
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pr_debug("Failed to wait for async response [rc=%d]\n", |
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rc); |
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break; |
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} |
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rc = opal_get_async_rc(msg); |
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if (rc != OPAL_SUCCESS) { |
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pr_debug("OPAL async call returned failed [rc=%d]\n", |
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rc); |
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break; |
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} |
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break; |
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case OPAL_SUCCESS: |
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break; |
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default: |
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pr_debug("OPAL write op-panel call failed [rc=%d]\n", rc); |
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} |
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opal_async_release_token(token); |
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return rc; |
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} |
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static ssize_t oppanel_write(struct file *filp, const char __user *userbuf, |
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size_t len, loff_t *f_pos) |
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{ |
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loff_t f_pos_prev = *f_pos; |
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ssize_t ret; |
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int rc; |
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if (!*f_pos) |
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memset(oppanel_data, ' ', oppanel_size); |
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else if (*f_pos >= oppanel_size) |
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return -EFBIG; |
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ret = simple_write_to_buffer(oppanel_data, oppanel_size, f_pos, userbuf, |
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len); |
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if (ret > 0) { |
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rc = __op_panel_update_display(); |
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if (rc != OPAL_SUCCESS) { |
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pr_err_ratelimited("OPAL call failed to write to op panel display [rc=%d]\n", |
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rc); |
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*f_pos = f_pos_prev; |
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return -EIO; |
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} |
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} |
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return ret; |
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} |
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static int oppanel_open(struct inode *inode, struct file *filp) |
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{ |
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if (!mutex_trylock(&oppanel_mutex)) { |
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pr_debug("Device Busy\n"); |
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return -EBUSY; |
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} |
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return 0; |
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} |
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static int oppanel_release(struct inode *inode, struct file *filp) |
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{ |
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mutex_unlock(&oppanel_mutex); |
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return 0; |
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} |
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static const struct file_operations oppanel_fops = { |
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.owner = THIS_MODULE, |
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.llseek = oppanel_llseek, |
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.read = oppanel_read, |
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.write = oppanel_write, |
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.open = oppanel_open, |
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.release = oppanel_release |
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}; |
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static struct miscdevice oppanel_dev = { |
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.minor = MISC_DYNAMIC_MINOR, |
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.name = "op_panel", |
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.fops = &oppanel_fops |
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}; |
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static int oppanel_probe(struct platform_device *pdev) |
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{ |
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struct device_node *np = pdev->dev.of_node; |
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u32 line_len; |
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int rc, i; |
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rc = of_property_read_u32(np, "#length", &line_len); |
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if (rc) { |
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pr_err_ratelimited("Operator panel length property not found\n"); |
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return rc; |
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} |
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rc = of_property_read_u32(np, "#lines", &num_lines); |
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if (rc) { |
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pr_err_ratelimited("Operator panel lines property not found\n"); |
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return rc; |
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} |
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oppanel_size = line_len * num_lines; |
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pr_devel("Operator panel of size %u found with %u lines of length %u\n", |
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oppanel_size, num_lines, line_len); |
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oppanel_data = kcalloc(oppanel_size, sizeof(*oppanel_data), GFP_KERNEL); |
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if (!oppanel_data) |
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return -ENOMEM; |
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oppanel_lines = kcalloc(num_lines, sizeof(oppanel_line_t), GFP_KERNEL); |
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if (!oppanel_lines) { |
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rc = -ENOMEM; |
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goto free_oppanel_data; |
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} |
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memset(oppanel_data, ' ', oppanel_size); |
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for (i = 0; i < num_lines; i++) { |
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oppanel_lines[i].line_len = cpu_to_be64(line_len); |
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oppanel_lines[i].line = cpu_to_be64(__pa(&oppanel_data[i * |
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line_len])); |
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} |
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rc = misc_register(&oppanel_dev); |
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if (rc) { |
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pr_err_ratelimited("Failed to register as misc device\n"); |
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goto free_oppanel; |
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} |
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return 0; |
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free_oppanel: |
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kfree(oppanel_lines); |
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free_oppanel_data: |
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kfree(oppanel_data); |
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return rc; |
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} |
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static int oppanel_remove(struct platform_device *pdev) |
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{ |
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misc_deregister(&oppanel_dev); |
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kfree(oppanel_lines); |
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kfree(oppanel_data); |
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return 0; |
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} |
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static const struct of_device_id oppanel_match[] = { |
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{ .compatible = "ibm,opal-oppanel" }, |
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{ }, |
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}; |
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static struct platform_driver oppanel_driver = { |
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.driver = { |
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.name = "powernv-op-panel", |
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.of_match_table = oppanel_match, |
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}, |
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.probe = oppanel_probe, |
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.remove = oppanel_remove, |
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}; |
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module_platform_driver(oppanel_driver); |
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MODULE_DEVICE_TABLE(of, oppanel_match); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_DESCRIPTION("PowerNV Operator Panel LCD Display Driver"); |
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MODULE_AUTHOR("Suraj Jitindar Singh <[email protected]>");
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