blob: 7076ede2003a4efaf86c6fafddae2689757d938b [file] [log] [blame]
John Wang5729e592020-09-30 13:08:32 +08001From dc37d698586a7ca4e4381ef7726249fa70d14c89 Mon Sep 17 00:00:00 2001
2From: Oskar Senft <osk@google.com>
3Date: Wed, 8 Aug 2018 10:15:05 -0400
4Subject: [PATCH 3/5] misc: aspeed: Add Aspeed UART routing control driver.
5
6This driver adds sysfs files that allow the BMC userspace to configure
7how UARTs and physical serial I/O ports are routed.
8
9Tested: Checked correct behavior (both read & write) on TYAN S7106
10board by manually changing routing settings and confirming that bits
11flow as expected. Tested for UART1 and UART3 as this board doesn't have
12the other UARTs wired up in a testable way.
13
14Signed-off-by: Oskar Senft <osk@google.com>
15Signed-off-by: Yong Li <yong.b.li@linux.intel.com>
16Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
17Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
18---
19 .../stable/sysfs-driver-aspeed-uart-routing | 14 +
20 .../misc-devices/aspeed-uart-routing.txt | 49 +++
21 drivers/misc/Kconfig | 6 +
22 drivers/misc/Makefile | 1 +
23 drivers/misc/aspeed-uart-routing.c | 383 ++++++++++++++++++
24 5 files changed, 453 insertions(+)
25 create mode 100644 Documentation/ABI/stable/sysfs-driver-aspeed-uart-routing
26 create mode 100644 Documentation/misc-devices/aspeed-uart-routing.txt
27 create mode 100644 drivers/misc/aspeed-uart-routing.c
28
29diff --git a/Documentation/ABI/stable/sysfs-driver-aspeed-uart-routing b/Documentation/ABI/stable/sysfs-driver-aspeed-uart-routing
30new file mode 100644
31index 000000000000..5068737d9c12
32--- /dev/null
33+++ b/Documentation/ABI/stable/sysfs-driver-aspeed-uart-routing
34@@ -0,0 +1,14 @@
35+What: /sys/bus/platform/drivers/aspeed-uart-routing/*/io*
36+Date: August 2018
37+Contact: Oskar Senft <osk@google.com>
38+Description: Configures the input source for the specific physical
39+ serial I/O port.
40+Users: OpenBMC. Proposed changes should be mailed to
41+ openbmc@lists.ozlabs.org
42+
43+What: /sys/bus/platform/drivers/aspeed-uart-routing/*/uart*
44+Date: August 2018
45+Contact: Oskar Senft <osk@google.com>
46+Description: Configures the input source for the specific UART.
47+Users: OpenBMC. Proposed changes should be mailed to
48+ openbmc@lists.ozlabs.org
49diff --git a/Documentation/misc-devices/aspeed-uart-routing.txt b/Documentation/misc-devices/aspeed-uart-routing.txt
50new file mode 100644
51index 000000000000..cf1c2a466875
52--- /dev/null
53+++ b/Documentation/misc-devices/aspeed-uart-routing.txt
54@@ -0,0 +1,49 @@
55+Kernel driver aspeed-uart-routing
56+=================================
57+
58+Supported chips:
59+ASPEED AST2500/AST2600
60+
61+Author:
62+Google LLC
63+
64+Description
65+-----------
66+
67+The Aspeed AST2500/AST2600 allows to dynamically route the inputs for the
68+built-in UARTS and physical serial I/O ports.
69+
70+This allows, for example, to connect the output of UART to another UART.
71+This can be used to enable host<->BMC communication via UARTs, e.g. to allow
72+access to the host's serial console.
73+
74+This driver is for the BMC side. The sysfs files allow the BMC userspace
75+which owns the system configuration policy, to configure how UARTs and
76+physical serial I/O ports are routed.
77+
78+The driver provides the following files in sysfs:
79+uart1 Configure the input signal to UART1.
80+uart2 Configure the input signal to UART2.
81+uart3 Configure the input signal to UART3.
82+uart4 Configure the input signal to UART4.
83+uart5 Configure the input signal to UART5.
84+io1 Configure the input signal to physical serial port 1.
85+io2 Configure the input signal to physical serial port 2.
86+io3 Configure the input signal to physical serial port 3.
87+io4 Configure the input signal to physical serial port 4.
88+io5 Configure the input signal to physical serial port 5.
89+
90+When read, each file shows the list of available options with the currently
91+selected option marked by square brackets "[]". The list of available options
92+depends on the selected file.
93+
94+Example:
95+$ cat /sys/bus/platform/drivers/aspeed-uart-routing/*.uart_routing/uart1
96+[io1] io2 io3 io4 uart2 uart3 uart4 io6
97+
98+In this case, UART1 gets its input signal from IO1 (physical serial port 1).
99+
100+$ echo -n "uart3" \
101+ >/sys/bus/platform/drivers/aspeed-uart-routing/*.uart_routing/uart1
102+$ cat /sys/bus/platform/drivers/aspeed-uart-routing/*.uart_routing/uart1
103+io1 io2 io3 io4 uart2 [uart3] uart4 io6
104diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
105index d8626a0d3e31..48a519c59bdf 100644
106--- a/drivers/misc/Kconfig
107+++ b/drivers/misc/Kconfig
108@@ -451,6 +451,12 @@ config MCTP_LPC
109 Implements the MCTP LPC binding via KCS LPC IO cycles for control and
110 LPC FWH cycles for data
111
112+config ASPEED_UART_ROUTING
113+ tristate "Aspeed ast2500 UART routing control"
114+ help
115+ If you want to configure UART routing on Aspeed BMC platforms, enable
116+ this option.
117+
118 config MISC_RTSX
119 tristate
120 default MISC_RTSX_PCI || MISC_RTSX_USB
121diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
122index 183970192ced..4e67e21c2e65 100644
123--- a/drivers/misc/Makefile
124+++ b/drivers/misc/Makefile
125@@ -60,3 +60,4 @@ obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o
126 obj-$(CONFIG_NPCM7XX_LPC_BPC) += npcm7xx-lpc-bpc.o
127 obj-$(CONFIG_NPCM7XX_PCI_MBOX) += npcm7xx-pci-mbox.o
128 obj-$(CONFIG_MCTP_LPC) += mctp-lpc.o
129+obj-$(CONFIG_ASPEED_UART_ROUTING) += aspeed-uart-routing.o
130diff --git a/drivers/misc/aspeed-uart-routing.c b/drivers/misc/aspeed-uart-routing.c
131new file mode 100644
132index 000000000000..21ef5d98c317
133--- /dev/null
134+++ b/drivers/misc/aspeed-uart-routing.c
135@@ -0,0 +1,383 @@
136+/*
137+ * UART Routing driver for Aspeed AST2500
138+ *
139+ * Copyright (c) 2018 Google LLC
140+ *
141+ * This program is free software; you can redistribute it and/or
142+ * modify it under the terms of the GNU General Public License
143+ * version 2 as published by the Free Software Foundation.
144+ *
145+ * This program is distributed in the hope that it will be useful,
146+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
147+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
148+ * GNU General Public License for more details.
149+ */
150+#include <linux/device.h>
151+#include <linux/module.h>
152+#include <linux/of_address.h>
153+#include <linux/of_platform.h>
154+
155+/* The Aspeed AST2500 allows to dynamically route the inputs for the built-in
156+ * UARTS and physical serial I/O ports.
157+ *
158+ * This allows, for example, to connect the output of UART to another UART.
159+ * This can be used to enable host<->BMC communication via UARTs, e.g. to allow
160+ * access to the host's serial console.
161+ *
162+ * This driver is for the BMC side. The sysfs files allow the BMC userspace
163+ * which owns the system configuration policy, to configure how UARTs and
164+ * physical serial I/O ports are routed.
165+ */
166+
167+#define ASPEED_HICRA_IO1 "io1"
168+#define ASPEED_HICRA_IO2 "io2"
169+#define ASPEED_HICRA_IO3 "io3"
170+#define ASPEED_HICRA_IO4 "io4"
171+#define ASPEED_HICRA_IO5 "io5"
172+#define ASPEED_HICRA_IO6 "io6"
173+#define ASPEED_HICRA_UART1 "uart1"
174+#define ASPEED_HICRA_UART2 "uart2"
175+#define ASPEED_HICRA_UART3 "uart3"
176+#define ASPEED_HICRA_UART4 "uart4"
177+#define ASPEED_HICRA_UART5 "uart5"
178+
179+struct aspeed_uart_routing {
180+ struct device *dev;
181+ void __iomem *regs;
182+ spinlock_t lock;
183+};
184+
185+struct aspeed_uart_routing_selector {
186+ struct device_attribute dev_attr;
187+ int shift;
188+ int mask;
189+ const char * const options[];
190+};
191+
192+#define to_routing_selector(_dev_attr) \
193+ container_of(_dev_attr, struct aspeed_uart_routing_selector, dev_attr)
194+
195+
196+static ssize_t aspeed_uart_routing_show(struct device *dev,
197+ struct device_attribute *attr,
198+ char *buf);
199+
200+static ssize_t aspeed_uart_routing_store(struct device *dev,
201+ struct device_attribute *attr,
202+ const char *buf, size_t count);
203+
204+#define ROUTING_ATTR(_name) { \
205+ .attr = {.name = _name, \
206+ .mode = VERIFY_OCTAL_PERMISSIONS(S_IWUSR | S_IRUGO) }, \
207+ .show = aspeed_uart_routing_show, \
208+ .store = aspeed_uart_routing_store, \
209+}
210+
211+static struct aspeed_uart_routing_selector uart5_sel = {
212+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_UART5),
213+ .shift = 28,
214+ .mask = 0xf,
215+ .options = {
216+ ASPEED_HICRA_IO5, // 0
217+ ASPEED_HICRA_IO1, // 1
218+ ASPEED_HICRA_IO2, // 2
219+ ASPEED_HICRA_IO3, // 3
220+ ASPEED_HICRA_IO4, // 4
221+ ASPEED_HICRA_UART1, // 5
222+ ASPEED_HICRA_UART2, // 6
223+ ASPEED_HICRA_UART3, // 7
224+ ASPEED_HICRA_UART4, // 8
225+ ASPEED_HICRA_IO6, // 9
226+ NULL, // NULL termination
227+ },
228+};
229+
230+static struct aspeed_uart_routing_selector uart4_sel = {
231+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_UART4),
232+ .shift = 25,
233+ .mask = 0x7,
234+ .options = {
235+ ASPEED_HICRA_IO4, // 0
236+ ASPEED_HICRA_IO1, // 1
237+ ASPEED_HICRA_IO2, // 2
238+ ASPEED_HICRA_IO3, // 3
239+ ASPEED_HICRA_UART1, // 4
240+ ASPEED_HICRA_UART2, // 5
241+ ASPEED_HICRA_UART3, // 6
242+ ASPEED_HICRA_IO6, // 7
243+ NULL, // NULL termination
244+ },
245+};
246+
247+static struct aspeed_uart_routing_selector uart3_sel = {
248+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_UART3),
249+ .shift = 22,
250+ .mask = 0x7,
251+ .options = {
252+ ASPEED_HICRA_IO3, // 0
253+ ASPEED_HICRA_IO4, // 1
254+ ASPEED_HICRA_IO1, // 2
255+ ASPEED_HICRA_IO2, // 3
256+ ASPEED_HICRA_UART4, // 4
257+ ASPEED_HICRA_UART1, // 5
258+ ASPEED_HICRA_UART2, // 6
259+ ASPEED_HICRA_IO6, // 7
260+ NULL, // NULL termination
261+ },
262+};
263+
264+static struct aspeed_uart_routing_selector uart2_sel = {
265+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_UART2),
266+ .shift = 19,
267+ .mask = 0x7,
268+ .options = {
269+ ASPEED_HICRA_IO2, // 0
270+ ASPEED_HICRA_IO3, // 1
271+ ASPEED_HICRA_IO4, // 2
272+ ASPEED_HICRA_IO1, // 3
273+ ASPEED_HICRA_UART3, // 4
274+ ASPEED_HICRA_UART4, // 5
275+ ASPEED_HICRA_UART1, // 6
276+ ASPEED_HICRA_IO6, // 7
277+ NULL, // NULL termination
278+ },
279+};
280+
281+static struct aspeed_uart_routing_selector uart1_sel = {
282+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_UART1),
283+ .shift = 16,
284+ .mask = 0x7,
285+ .options = {
286+ ASPEED_HICRA_IO1, // 0
287+ ASPEED_HICRA_IO2, // 1
288+ ASPEED_HICRA_IO3, // 2
289+ ASPEED_HICRA_IO4, // 3
290+ ASPEED_HICRA_UART2, // 4
291+ ASPEED_HICRA_UART3, // 5
292+ ASPEED_HICRA_UART4, // 6
293+ ASPEED_HICRA_IO6, // 7
294+ NULL, // NULL termination
295+ },
296+};
297+
298+static struct aspeed_uart_routing_selector io5_sel = {
299+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_IO5),
300+ .shift = 12,
301+ .mask = 0x7,
302+ .options = {
303+ ASPEED_HICRA_UART5, // 0
304+ ASPEED_HICRA_UART1, // 1
305+ ASPEED_HICRA_UART2, // 2
306+ ASPEED_HICRA_UART3, // 3
307+ ASPEED_HICRA_UART4, // 4
308+ ASPEED_HICRA_IO1, // 5
309+ ASPEED_HICRA_IO3, // 6
310+ ASPEED_HICRA_IO6, // 7
311+ NULL, // NULL termination
312+ },
313+};
314+
315+static struct aspeed_uart_routing_selector io4_sel = {
316+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_IO4),
317+ .shift = 9,
318+ .mask = 0x7,
319+ .options = {
320+ ASPEED_HICRA_UART4, // 0
321+ ASPEED_HICRA_UART5, // 1
322+ ASPEED_HICRA_UART1, // 2
323+ ASPEED_HICRA_UART2, // 3
324+ ASPEED_HICRA_UART3, // 4
325+ ASPEED_HICRA_IO1, // 5
326+ ASPEED_HICRA_IO2, // 6
327+ ASPEED_HICRA_IO6, // 7
328+ NULL, // NULL termination
329+ },
330+};
331+
332+static struct aspeed_uart_routing_selector io3_sel = {
333+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_IO3),
334+ .shift = 6,
335+ .mask = 0x7,
336+ .options = {
337+ ASPEED_HICRA_UART3, // 0
338+ ASPEED_HICRA_UART4, // 1
339+ ASPEED_HICRA_UART5, // 2
340+ ASPEED_HICRA_UART1, // 3
341+ ASPEED_HICRA_UART2, // 4
342+ ASPEED_HICRA_IO1, // 5
343+ ASPEED_HICRA_IO2, // 6
344+ ASPEED_HICRA_IO6, // 7
345+ NULL, // NULL termination
346+ },
347+};
348+
349+static struct aspeed_uart_routing_selector io2_sel = {
350+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_IO2),
351+ .shift = 3,
352+ .mask = 0x7,
353+ .options = {
354+ ASPEED_HICRA_UART2, // 0
355+ ASPEED_HICRA_UART3, // 1
356+ ASPEED_HICRA_UART4, // 2
357+ ASPEED_HICRA_UART5, // 3
358+ ASPEED_HICRA_UART1, // 4
359+ ASPEED_HICRA_IO3, // 5
360+ ASPEED_HICRA_IO4, // 6
361+ ASPEED_HICRA_IO6, // 7
362+ NULL, // NULL termination
363+ },
364+};
365+
366+static struct aspeed_uart_routing_selector io1_sel = {
367+ .dev_attr = ROUTING_ATTR(ASPEED_HICRA_IO1),
368+ .shift = 0,
369+ .mask = 0x7,
370+ .options = {
371+ ASPEED_HICRA_UART1, // 0
372+ ASPEED_HICRA_UART2, // 1
373+ ASPEED_HICRA_UART3, // 2
374+ ASPEED_HICRA_UART4, // 3
375+ ASPEED_HICRA_UART5, // 4
376+ ASPEED_HICRA_IO3, // 5
377+ ASPEED_HICRA_IO4, // 6
378+ ASPEED_HICRA_IO6, // 7
379+ NULL, // NULL termination
380+ },
381+};
382+
383+
384+static struct attribute *aspeed_uart_routing_attrs[] = {
385+ &uart1_sel.dev_attr.attr,
386+ &uart2_sel.dev_attr.attr,
387+ &uart3_sel.dev_attr.attr,
388+ &uart4_sel.dev_attr.attr,
389+ &uart5_sel.dev_attr.attr,
390+ &io1_sel.dev_attr.attr,
391+ &io2_sel.dev_attr.attr,
392+ &io3_sel.dev_attr.attr,
393+ &io4_sel.dev_attr.attr,
394+ &io5_sel.dev_attr.attr,
395+ NULL,
396+};
397+
398+static const struct attribute_group aspeed_uart_routing_attr_group = {
399+ .attrs = aspeed_uart_routing_attrs,
400+};
401+
402+static ssize_t aspeed_uart_routing_show(struct device *dev,
403+ struct device_attribute *attr,
404+ char *buf)
405+{
406+ struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
407+ struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
408+ int val, pos, len;
409+
410+ val = (readl(uart_routing->regs) >> sel->shift) & sel->mask;
411+
412+ len = 0;
413+ for (pos = 0; sel->options[pos] != NULL; ++pos) {
414+ if (pos == val) {
415+ len += snprintf(buf + len, PAGE_SIZE - 1 - len,
416+ "[%s] ", sel->options[pos]);
417+ } else {
418+ len += snprintf(buf + len, PAGE_SIZE - 1 - len,
419+ "%s ", sel->options[pos]);
420+ }
421+ }
422+
423+ if (val >= pos) {
424+ len += snprintf(buf + len, PAGE_SIZE - 1 - len,
425+ "[unknown(%d)]", val);
426+ }
427+
428+ len += snprintf(buf + len, PAGE_SIZE - 1 - len, "\n");
429+
430+ return len;
431+}
432+
433+static ssize_t aspeed_uart_routing_store(struct device *dev,
434+ struct device_attribute *attr,
435+ const char *buf, size_t count)
436+{
437+ struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
438+ struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
439+ int val;
440+ u32 reg;
441+
442+ val = match_string(sel->options, -1, buf);
443+ if (val < 0) {
444+ dev_err(dev, "invalid value \"%s\"\n", buf);
445+ return -EINVAL;
446+ }
447+
448+ spin_lock(&uart_routing->lock);
449+ reg = readl(uart_routing->regs);
450+ // Zero out existing value in specified bits.
451+ reg &= ~(sel->mask << sel->shift);
452+ // Set new value in specified bits.
453+ reg |= (val & sel->mask) << sel->shift;
454+ writel(reg, uart_routing->regs);
455+ spin_unlock(&uart_routing->lock);
456+
457+ return count;
458+}
459+
460+static int aspeed_uart_routing_probe(struct platform_device *pdev)
461+{
462+ struct aspeed_uart_routing *uart_routing;
463+ struct resource *res;
464+ int rc;
465+
466+ uart_routing = devm_kzalloc(&pdev->dev,
467+ sizeof(*uart_routing),
468+ GFP_KERNEL);
469+ if (!uart_routing)
470+ return -ENOMEM;
471+
472+ spin_lock_init(&uart_routing->lock);
473+ uart_routing->dev = &pdev->dev;
474+
475+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
476+ uart_routing->regs = devm_ioremap_resource(&pdev->dev, res);
477+ if (IS_ERR(uart_routing->regs))
478+ return PTR_ERR(uart_routing->regs);
479+
480+ rc = sysfs_create_group(&uart_routing->dev->kobj,
481+ &aspeed_uart_routing_attr_group);
482+ if (rc < 0)
483+ return rc;
484+
485+ platform_set_drvdata(pdev, uart_routing);
486+
487+ return 0;
488+}
489+
490+static int aspeed_uart_routing_remove(struct platform_device *pdev)
491+{
492+ struct aspeed_uart_routing *uart_routing = platform_get_drvdata(pdev);
493+
494+ sysfs_remove_group(&uart_routing->dev->kobj,
495+ &aspeed_uart_routing_attr_group);
496+
497+ return 0;
498+}
499+
500+static const struct of_device_id aspeed_uart_routing_table[] = {
501+ { .compatible = "aspeed,ast2500-uart-routing" },
502+ { },
503+};
504+
505+static struct platform_driver aspeed_uart_routing_driver = {
506+ .driver = {
507+ .name = "aspeed-uart-routing",
508+ .of_match_table = aspeed_uart_routing_table,
509+ },
510+ .probe = aspeed_uart_routing_probe,
511+ .remove = aspeed_uart_routing_remove,
512+};
513+
514+module_platform_driver(aspeed_uart_routing_driver);
515+
516+MODULE_AUTHOR("Oskar Senft <osk@google.com>");
517+MODULE_LICENSE("GPL v2");
518+MODULE_DESCRIPTION("Driver to configure Aspeed UART routing");
519--
5202.25.1
521