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2015-10-06misc: atmel_tclib: get and use slow clockBoris Brezillon1-0/+1
Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang") added a workaround for the slow clock as it is not properly handled by its users. Get and use the slow clock as it is necessary for the timer counters. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Thierry Reding <thierry.reding@gmail.com>
2014-09-08ARM: at91/tclib: mask interruptions at shutdown and probeGaël PORTAY1-0/+5
Shutdown properly the timer counter block by masking interruptions. Otherwise, a segmentation may happen when kexec-ing a new kernel (see backtrace below). An interruption may happen before the handler is set, leading to a kernel segmentation fault. Furthermore, we make sure the interruptions are masked when the driver is initialized. This will prevent freshly kexec-ed kernel from crashing when launched from a kernel which does not properly mask interruptions at shutdown. The backtrace below happened after kexec-ing a new kernel, from a kernel that did not shut down properly leaving interruptions unmasked. Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 80000005 [#1] ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0+ #144 task: c1828aa0 ti: c182a000 task.ti: c182a000 PC is at 0x0 LR is at ch2_irq+0x28/0x30 pc : [<00000000>] lr : [<c01db904>] psr: 000000d3 sp : c182bd38 ip : c182bd48 fp : c182bd44 r10: c0373390 r9 : c1825b00 r8 : 60000053 r7 : 00000000 r6 : 00000000 r5 : 00000013 r4 : c036e800 r3 : 00000000 r2 : 00002004 r1 : c036e760 r0 : c036e760 Flags: nzcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 0005317f Table: 20004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc182a1c0) Stack: (0xc182bd38 to 0xc182c000) bd20: c182bd7c c182bd48 bd40: c0045430 c01db8ec 00000000 c18c6f40 c182bd74 c1825b00 c035cec4 00000000 bd60: c182be2c 60000053 c1825b34 00000000 c182bd94 c182bd80 c0045570 c0045408 bd80: 00000000 c1825b00 c182bdac c182bd98 c0047f34 c0045550 00000013 c036619c bda0: c182bdc4 c182bdb0 c0044da4 c0047e98 0000007f 00000013 c182bde4 c182bdc8 bdc0: c0009e34 c0044d8c fefff000 c0046728 60000053 ffffffff c182bdf4 c182bde8 bde0: c00086a8 c0009ddc c182be74 c182bdf8 c000cb80 c0008674 00000000 00000013 be00: 00000000 00014200 c1825b00 c036e800 00000013 c035ed98 60000053 c1825b34 be20: 00000000 c182be74 c182be20 c182be40 c0047994 c0046728 60000053 ffffffff be40: 00000013 c036e800 c182be64 c1825b00 00000013 c036e800 c035ed98 c03874bc be60: 00000004 c036e700 c182be94 c182be78 c004689c c0046398 c036e760 c18c6080 be80: 00000000 c035ed10 c182bedc c182be98 c0348b08 c004684c 0000000c c034dac8 bea0: 004c4b3f c028c338 c036e760 00000013 c014ecc8 c18e67e0 c035b9c0 c0348884 bec0: c035b9c0 c182a020 00000000 00000000 c182bf54 c182bee0 c00089fc c0348894 bee0: c00da51c c1ffcc78 c182bf0c c182bef8 c002d100 c002d09c c1ffcc78 00000000 bf00: c182bf54 c182bf10 c002d308 c0336570 c182bf3c c0334e44 00000003 00000003 bf20: 00000030 c0334b44 c0044d74 00000003 00000003 c034dac8 c0350a94 c0373440 bf40: c0373440 00000030 c182bf94 c182bf58 c0336d24 c000890c 00000003 00000003 bf60: c0336560 c182bf64 c182bf64 6e616e0d 00000000 c0272fc8 00000000 00000000 bf80: 00000000 00000000 c182bfac c182bf98 c0272fd8 c0336bd8 c182a000 00000000 bfa0: 00000000 c182bfb0 c00095d0 c0272fd8 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 374d27cd 33cc33e4 Backtrace: [<c01db8dc>] (ch2_irq) from [<c0045430>] (handle_irq_event_percpu+0x38/0x148) [<c00453f8>] (handle_irq_event_percpu) from [<c0045570>] (handle_irq_event+0x30/0x40) r10:00000000 r9:c1825b34 r8:60000053 r7:c182be2c r6:00000000 r5:c035cec4 r4:c1825b00 [<c0045540>] (handle_irq_event) from [<c0047f34>] (handle_fasteoi_irq+0xac/0x11c) r4:c1825b00 r3:00000000 [<c0047e88>] (handle_fasteoi_irq) from [<c0044da4>] (generic_handle_irq+0x28/0x38) r5:c036619c r4:00000013 [<c0044d7c>] (generic_handle_irq) from [<c0009e34>] (handle_IRQ+0x68/0x88) r4:00000013 r3:0000007f [<c0009dcc>] (handle_IRQ) from [<c00086a8>] (at91_aic_handle_irq+0x44/0x4c) r6:ffffffff r5:60000053 r4:c0046728 r3:fefff000 [<c0008664>] (at91_aic_handle_irq) from [<c000cb80>] (__irq_svc+0x40/0x4c) Exception stack(0xc182bdf8 to 0xc182be40) bde0: 00000000 00000013 be00: 00000000 00014200 c1825b00 c036e800 00000013 c035ed98 60000053 c1825b34 be20: 00000000 c182be74 c182be20 c182be40 c0047994 c0046728 60000053 ffffffff [<c0046388>] (__setup_irq) from [<c004689c>] (setup_irq+0x60/0x8c) r10:c036e700 r9:00000004 r8:c03874bc r7:c035ed98 r6:c036e800 r5:00000013 r4:c1825b00 [<c004683c>] (setup_irq) from [<c0348b08>] (tcb_clksrc_init+0x284/0x31c) r6:c035ed10 r5:00000000 r4:c18c6080 r3:c036e760 [<c0348884>] (tcb_clksrc_init) from [<c00089fc>] (do_one_initcall+0x100/0x1b4) r10:00000000 r9:00000000 r8:c182a020 r7:c035b9c0 r6:c0348884 r5:c035b9c0 r4:c18e67e0 [<c00088fc>] (do_one_initcall) from [<c0336d24>] (kernel_init_freeable+0x15c/0x224) r9:00000030 r8:c0373440 r7:c0373440 r6:c0350a94 r5:c034dac8 r4:00000003 [<c0336bc8>] (kernel_init_freeable) from [<c0272fd8>] (kernel_init+0x10/0xec) r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0272fc8 r4:00000000 [<c0272fc8>] (kernel_init) from [<c00095d0>] (ret_from_fork+0x14/0x24) r4:00000000 r3:c182a000 Code: bad PC value ---[ end trace 5b30f0017e282e47 ]--- Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Gaël PORTAY <gael.portay@gmail.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-09-08ARM: at91/tclib: move initialization from alloc to probeGaël PORTAY1-3/+5
Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately reporting resource related issues when a TC block user request a TC block. Moreover, resources retrieval are usually done in the probe function, thus moving them add some consistency with other drivers. Initialization is done once, ie not every time a tc block is requested. If it fails, the device is not appended to the list of tc blocks. Furhermore, the device id is retrieved at probe as well, avoiding parsing DT every time the user requests of tc block. Signed-off-by: Gaël PORTAY <gael.portay@gmail.com> Acked-by: Thierry Reding <thierry.reding@gmail.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2012-09-11misc/atmel_tc: make atmel_tc.tcb_config member point to const dataUwe Kleine-König1-1/+1
This prepares *of_device_id.data becoming const. Without this change the following warning would occur: drivers/misc/atmel_tclib.c: In function 'tc_probe': drivers/misc/atmel_tclib.c:170: warning: assignment discards qualifiers from pointer target type Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2012-03-01ARM: at91/tc/clocksource: Add 32 bit variant to Timer CounterNicolas Ferre1-0/+10
Some SoC have a 32 bit variant of Timer Counter Blocks. We do not need the chaining of two 16 bit counters anymore for them. The SoC nature is deduced from the device tree "compatible" string. For non-device-tree configurations, backward compatibility is maintained by using the default 16 bit counter configuration. This patch addresses both the atmel_tclib and its user: tcb_clksrc clocksource. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2008-03-04atmel_tc libraryDavid Brownell1-0/+252
Create <linux/atmel_tc.h> based on <asm-arm/arch-at91/at91-tc.h> and the at91sam9263 and at32ap7000 datasheets. Most AT91 and AT32 SOCs have one or two of these TC blocks, which include three 16-bit timers that can be interconnected in various ways. These TC blocks can be used for external interfacing (such as PWM and measurement), or used as somewhat quirky sixteen-bit timers. Changes relative to the original version: * Drop unneeded inclusion of <linux/mutex.h> * Support an arbitrary number of TC blocks * Return a struct with information about a TC block from atmel_tc_alloc() instead of using a combination of return values and "out" parameters. * ioremap() the I/O registers on allocation * Look up clocks and irqs for all channels * Add "name" parameter to atmel_tc_alloc() and use this when requesting the iomem resource. * Check if the platform provided the necessary resources at probe() time instead of when the TCB is allocated. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>