Hi Pankaj, Joachim, Am Dienstag, 23. September 2014, 20:12:50 schrieb Joachim Eastwood: > On 22 September 2014 06:40, Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> wrote: > > Currently a syscon entity can be only registered directly through a > > platform device that binds to a dedicated syscon driver. However in > > certain use cases it is desirable to make a device used with another > > driver a syscon interface provider. > > > > For example, certain SoCs (e.g. Exynos) contain system controller > > blocks which perform various functions such as power domain control, > > CPU power management, low power mode control, but in addition contain > > certain IP integration glue, such as various signal masks, > > coprocessor power control, etc. In such case, there is a need to have > > a dedicated driver for such system controller but also share registers > > with other drivers. The latter is where the syscon interface is helpful. > > > > In case of DT based platforms, this patch decouples syscon object from > > syscon platform driver, and allows to create syscon objects first time > > when it is required by calling of syscon_regmap_lookup_by APIs and keep > > a list of such syscon objects along with syscon provider device_nodes > > and regmap handles. > > > > For non-DT based platforms, this patch keeps syscon platform driver > > structure where is can be probed and such non-DT based drivers can use > > syscon_regmap_lookup_by_pdev API and get access to regmap handles. > > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, > > we can completly remove platform driver of syscon, and keep only helper > > functions to get regmap handles. > > > > Suggested-by: Arnd Bergmann <arnd@xxxxxxxx> > > Suggested-by: Tomasz Figa <tomasz.figa@xxxxxxxxx> > > Tested-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx> > > Tested-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> > > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> > > I wrote a clk driver using syscon and your patch. clk driver uses > CLK_OF_DECLARE, btw. > > It works but I get a '(null): Failed to create debugfs directory' > message in the boot log. > > Tested-by: Joachim Eastwood <manabian@xxxxxxxxx> on Rockchip platforms this syscon support also helps quite a bit, as the pll lock-status is sitting in an external syscon register, so setting target pll-rates through assigned-clocks is not easily doable without it. Therefore I'm very much looking forward to this. Similar to Joachim I get an error about debugfs from regmap, which seems to be caused by name = dev_name(map->dev); returning NULL in regmap_debugfs_init in regmap-debugfs.c for such an "early" syscon. [...] __set_clk_rates: setting cpll from 384000000 to 891000000 rockchip_rk3066_pll_set_rate: trying to get grf rockchip_rk3066_pll_set_rate: changing pll_cpll from 384000000 to 891000000 with a parent rate of 24000000 __set_clk_rates: cpll is now 891000000 Architected cp15 timer(s) running at 24.00MHz (virt). [...] regulator-dummy: no parameters NET: Registered protocol family 16 DMA: preallocated 256 KiB pool for atomic coherent allocations Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc1+ #1184 task: ee069b40 ti: ee06a000 task.ti: ee06a000 PC is at strlen+0xc/0x20 LR is at __create_file+0x6c/0x1d0 pc : [<c01a02f8>] lr : [<c01725f0>] psr: 60000153 sp : ee06bea8 ip : 0000000e fp : 00000000 r10: ee06a000 r9 : 00000000 r8 : 00000000 r7 : c07ecb20 r6 : edc02cc0 r5 : 000041ed r4 : 00000000 r3 : 00000001 r2 : 00000000 r1 : a0000153 r0 : 00000000 Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 0000406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee06a240) Stack: (0xee06bea8 to 0xee06c000) bea0: 00000000 000041ed ee002400 c07efc60 00000000 c05a9e50 bec0: c058c510 c01727c8 00000000 edc02cc0 ee0024b0 c021d410 ee002400 00000000 bee0: ee02ff40 c0793494 c07ab080 c021d6b4 00000000 ee11bbc0 c0782c58 c058c518 bf00: 00000000 c0008970 ee0f7f00 c00f9f54 ee0f7f00 ee0f7c80 ee0f7c00 c03fddc4 bf20: c07cda04 00000000 c054c8a4 c00fa0e0 c0575514 ef7fccc5 00000000 c0034fd0 bf40: 00000000 00000000 c054c8a4 c054bcd4 000000bd 00000002 c0786394 00000002 bf60: c059e840 c07ab080 c05a9e50 000000bd 00000000 00000000 00000000 c0575c94 bf80: 00000002 00000002 c0575514 ee06a000 00000000 c03f38f8 00000000 00000000 bfa0: 00000000 c03f3900 00000000 c000e7f8 00000000 00000000 00000000 00000000 bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 bfe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff [<c01a02f8>] (strlen) from [<c01725f0>] (__create_file+0x6c/0x1d0) [<c01725f0>] (__create_file) from [<c01727c8>] (debugfs_create_dir+0x18/0x1c) [<c01727c8>] (debugfs_create_dir) from [<c021d410>] (regmap_debugfs_init+0xd0/0x254) [<c021d410>] (regmap_debugfs_init) from [<c021d6b4>] (regmap_debugfs_initcall+0x5c/0xbc) [<c021d6b4>] (regmap_debugfs_initcall) from [<c058c518>] (regmap_initcall+0x8/0x10) [<c058c518>] (regmap_initcall) from [<c0008970>] (do_one_initcall+0x110/0x1bc) [<c0008970>] (do_one_initcall) from [<c0575c94>] (kernel_init_freeable+0xfc/0x1c8) [<c0575c94>] (kernel_init_freeable) from [<c03f3900>] (kernel_init+0x8/0xe4) [<c03f3900>] (kernel_init) from [<c000e7f8>] (ret_from_fork+0x14/0x3c) Code: c040e4cc e1a03000 e1a02003 e2833001 (e5d21000) ---[ end trace fa51dc7fc31bd989 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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