From 43a1dd9b5fc64184e578ac1570d016d2862e00b2 Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Wed, 29 Jun 2016 13:38:39 +1000 Subject: [PATCH] powerpc/powernv: Add driver for operator panel on FSP machines Implement new character device driver to allow access from user space to the operator panel display present on IBM Power Systems machines with FSPs. This will allow status information to be presented on the display which is visible to a user. The driver implements a character buffer which a user can read/write by accessing the device (/dev/op_panel). This buffer is then displayed on the operator panel display. Any attempt to write past the last character position will have no effect and attempts to write more characters than the size of the display will be truncated. The device may only be accessed by a single process at a time. Signed-off-by: Suraj Jitindar Singh Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- MAINTAINERS | 6 + arch/powerpc/configs/powernv_defconfig | 1 + arch/powerpc/include/asm/opal.h | 2 + .../powerpc/platforms/powernv/opal-wrappers.S | 1 + arch/powerpc/platforms/powernv/opal.c | 5 + drivers/char/Kconfig | 14 ++ drivers/char/Makefile | 1 + drivers/char/powernv-op-panel.c | 223 ++++++++++++++++++ 8 files changed, 253 insertions(+) create mode 100644 drivers/char/powernv-op-panel.c diff --git a/MAINTAINERS b/MAINTAINERS index ea80d71fffaa..3318633732d0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9081,6 +9081,12 @@ F: drivers/firmware/psci.c F: include/linux/psci.h F: include/uapi/linux/psci.h +POWERNV OPERATOR PANEL LCD DISPLAY DRIVER +M: Suraj Jitindar Singh +L: linuxppc-dev@lists.ozlabs.org +S: Maintained +F: drivers/char/powernv-op-panel.c + PNP SUPPORT M: "Rafael J. Wysocki" S: Maintained diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig index 045031048f8d..959d32bc7337 100644 --- a/arch/powerpc/configs/powernv_defconfig +++ b/arch/powerpc/configs/powernv_defconfig @@ -181,6 +181,7 @@ CONFIG_SERIAL_8250=y CONFIG_SERIAL_8250_CONSOLE=y CONFIG_SERIAL_JSM=m CONFIG_VIRTIO_CONSOLE=m +CONFIG_POWERNV_OP_PANEL=m CONFIG_IPMI_HANDLER=y CONFIG_IPMI_DEVICE_INTERFACE=y CONFIG_IPMI_POWERNV=y diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 9ab52e27cf71..3b369e9cb6e1 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -178,6 +178,8 @@ int64_t opal_dump_ack(uint32_t dump_id); int64_t opal_dump_resend_notification(void); int64_t opal_get_msg(uint64_t buffer, uint64_t size); +int64_t opal_write_oppanel_async(uint64_t token, oppanel_line_t *lines, + uint64_t num_lines); int64_t opal_check_completion(uint64_t buffer, uint64_t size, uint64_t token); int64_t opal_sync_host_reboot(void); int64_t opal_get_param(uint64_t token, uint32_t param_id, uint64_t buffer, diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 3ea1a8559035..7979d6d43bff 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -278,6 +278,7 @@ OPAL_CALL(opal_dump_info2, OPAL_DUMP_INFO2); OPAL_CALL(opal_dump_read, OPAL_DUMP_READ); OPAL_CALL(opal_dump_ack, OPAL_DUMP_ACK); OPAL_CALL(opal_get_msg, OPAL_GET_MSG); +OPAL_CALL(opal_write_oppanel_async, OPAL_WRITE_OPPANEL_ASYNC); OPAL_CALL(opal_check_completion, OPAL_CHECK_ASYNC_COMPLETION); OPAL_CALL(opal_dump_resend_notification, OPAL_DUMP_RESEND); OPAL_CALL(opal_sync_host_reboot, OPAL_SYNC_HOST_REBOOT); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 0256d0729252..228751a0d8c6 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -751,6 +751,9 @@ static int __init opal_init(void) opal_pdev_init(opal_node, "ibm,opal-flash"); opal_pdev_init(opal_node, "ibm,opal-prd"); + /* Initialise platform device: oppanel interface */ + opal_pdev_init(opal_node, "ibm,opal-oppanel"); + /* Initialise OPAL kmsg dumper for flushing console on panic */ opal_kmsg_init(); @@ -885,3 +888,5 @@ EXPORT_SYMBOL_GPL(opal_i2c_request); /* Export these symbols for PowerNV LED class driver */ EXPORT_SYMBOL_GPL(opal_leds_get_ind); EXPORT_SYMBOL_GPL(opal_leds_set_ind); +/* Export this symbol for PowerNV Operator Panel class driver */ +EXPORT_SYMBOL_GPL(opal_write_oppanel_async); diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 601f64fcc890..fdb8f3e10b6f 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -178,6 +178,20 @@ config IBM_BSR of threads across a large system which avoids bouncing a cacheline between several cores on a system +config POWERNV_OP_PANEL + tristate "IBM POWERNV Operator Panel Display support" + depends on PPC_POWERNV + default m + help + If you say Y here, a special character device node, /dev/op_panel, + will be created which exposes the operator panel display on IBM + Power Systems machines with FSPs. + + If you don't require access to the operator panel display from user + space, say N. + + If unsure, say M here to build it as a module called powernv-op-panel. + source "drivers/char/ipmi/Kconfig" config DS1620 diff --git a/drivers/char/Makefile b/drivers/char/Makefile index d8a7579300d2..55d16bf3ccc5 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -60,3 +60,4 @@ js-rtc-y = rtc.o obj-$(CONFIG_TILE_SROM) += tile-srom.o obj-$(CONFIG_XILLYBUS) += xillybus/ +obj-$(CONFIG_POWERNV_OP_PANEL) += powernv-op-panel.o diff --git a/drivers/char/powernv-op-panel.c b/drivers/char/powernv-op-panel.c new file mode 100644 index 000000000000..a45dabcc8e10 --- /dev/null +++ b/drivers/char/powernv-op-panel.c @@ -0,0 +1,223 @@ +/* + * OPAL Operator Panel Display Driver + * + * Copyright 2016, Suraj Jitindar Singh, IBM Corporation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* + * This driver creates a character device (/dev/op_panel) which exposes the + * operator panel (character LCD display) on IBM Power Systems machines + * with FSPs. + * A character buffer written to the device will be displayed on the + * operator panel. + */ + +static DEFINE_MUTEX(oppanel_mutex); + +static u32 num_lines, oppanel_size; +static oppanel_line_t *oppanel_lines; +static char *oppanel_data; + +static loff_t oppanel_llseek(struct file *filp, loff_t offset, int whence) +{ + return fixed_size_llseek(filp, offset, whence, oppanel_size); +} + +static ssize_t oppanel_read(struct file *filp, char __user *userbuf, size_t len, + loff_t *f_pos) +{ + return simple_read_from_buffer(userbuf, len, f_pos, oppanel_data, + oppanel_size); +} + +static int __op_panel_update_display(void) +{ + struct opal_msg msg; + int rc, token; + + token = opal_async_get_token_interruptible(); + if (token < 0) { + if (token != -ERESTARTSYS) + pr_debug("Couldn't get OPAL async token [token=%d]\n", + token); + return token; + } + + rc = opal_write_oppanel_async(token, oppanel_lines, num_lines); + switch (rc) { + case OPAL_ASYNC_COMPLETION: + rc = opal_async_wait_response(token, &msg); + if (rc) { + pr_debug("Failed to wait for async response [rc=%d]\n", + rc); + break; + } + rc = opal_get_async_rc(msg); + if (rc != OPAL_SUCCESS) { + pr_debug("OPAL async call returned failed [rc=%d]\n", + rc); + break; + } + case OPAL_SUCCESS: + break; + default: + pr_debug("OPAL write op-panel call failed [rc=%d]\n", rc); + } + + opal_async_release_token(token); + return rc; +} + +static ssize_t oppanel_write(struct file *filp, const char __user *userbuf, + size_t len, loff_t *f_pos) +{ + loff_t f_pos_prev = *f_pos; + ssize_t ret; + int rc; + + if (!*f_pos) + memset(oppanel_data, ' ', oppanel_size); + else if (*f_pos >= oppanel_size) + return -EFBIG; + + ret = simple_write_to_buffer(oppanel_data, oppanel_size, f_pos, userbuf, + len); + if (ret > 0) { + rc = __op_panel_update_display(); + if (rc != OPAL_SUCCESS) { + pr_err_ratelimited("OPAL call failed to write to op panel display [rc=%d]\n", + rc); + *f_pos = f_pos_prev; + return -EIO; + } + } + return ret; +} + +static int oppanel_open(struct inode *inode, struct file *filp) +{ + if (!mutex_trylock(&oppanel_mutex)) { + pr_debug("Device Busy\n"); + return -EBUSY; + } + return 0; +} + +static int oppanel_release(struct inode *inode, struct file *filp) +{ + mutex_unlock(&oppanel_mutex); + return 0; +} + +static const struct file_operations oppanel_fops = { + .owner = THIS_MODULE, + .llseek = oppanel_llseek, + .read = oppanel_read, + .write = oppanel_write, + .open = oppanel_open, + .release = oppanel_release +}; + +static struct miscdevice oppanel_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "op_panel", + .fops = &oppanel_fops +}; + +static int oppanel_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + u32 line_len; + int rc, i; + + rc = of_property_read_u32(np, "#length", &line_len); + if (rc) { + pr_err_ratelimited("Operator panel length property not found\n"); + return rc; + } + rc = of_property_read_u32(np, "#lines", &num_lines); + if (rc) { + pr_err_ratelimited("Operator panel lines property not found\n"); + return rc; + } + oppanel_size = line_len * num_lines; + + pr_devel("Operator panel of size %u found with %u lines of length %u\n", + oppanel_size, num_lines, line_len); + + oppanel_data = kcalloc(oppanel_size, sizeof(*oppanel_data), GFP_KERNEL); + if (!oppanel_data) + return -ENOMEM; + + oppanel_lines = kcalloc(num_lines, sizeof(oppanel_line_t), GFP_KERNEL); + if (!oppanel_lines) { + rc = -ENOMEM; + goto free_oppanel_data; + } + + memset(oppanel_data, ' ', oppanel_size); + for (i = 0; i < num_lines; i++) { + oppanel_lines[i].line_len = cpu_to_be64(line_len); + oppanel_lines[i].line = cpu_to_be64(__pa(&oppanel_data[i * + line_len])); + } + + rc = misc_register(&oppanel_dev); + if (rc) { + pr_err_ratelimited("Failed to register as misc device\n"); + goto free_oppanel; + } + + return 0; + +free_oppanel: + kfree(oppanel_lines); +free_oppanel_data: + kfree(oppanel_data); + return rc; +} + +static int oppanel_remove(struct platform_device *pdev) +{ + misc_deregister(&oppanel_dev); + kfree(oppanel_lines); + kfree(oppanel_data); + return 0; +} + +static const struct of_device_id oppanel_match[] = { + { .compatible = "ibm,opal-oppanel" }, + { }, +}; + +static struct platform_driver oppanel_driver = { + .driver = { + .name = "powernv-op-panel", + .of_match_table = oppanel_match, + }, + .probe = oppanel_probe, + .remove = oppanel_remove, +}; + +module_platform_driver(oppanel_driver); + +MODULE_DEVICE_TABLE(of, oppanel_match); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("PowerNV Operator Panel LCD Display Driver"); +MODULE_AUTHOR("Suraj Jitindar Singh ");