From mboxrd@z Thu Jan 1 00:00:00 1970 From: b32955@freescale.com (Huang Shijie) Date: Fri, 24 May 2013 15:16:53 +0800 Subject: [PATCH V2 1/6] drivers: bus: add a new driver for WEIM In-Reply-To: <201305231509.57651.arnd@arndb.de> References: <1369296978-7669-1-git-send-email-b32955@freescale.com> <201305231153.38111.arnd@arndb.de> <20130523115505.GG32299@pengutronix.de> <201305231509.57651.arnd@arndb.de> Message-ID: <519F13E5.2040701@freescale.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2013?05?23? 21:09, Arnd Bergmann ??: > OTOH, I agree that it would be nicer if the clk could remain turned > off as long as no children are active. Can we do a clk_disable() > after setting up the timings for the children and then expect those > to actually start up the clk again when they need it? > > Or to take things further: would it make sense to represent WEIM > itself as a clock driver and perform the settings for each child > only when it sets up its own clk? > If the child's subsystem supports it, we can do it. The mtd nand does support this feature, it has @select_chip() hook. We can enable/disable the clock in the @select_chip(). But the mtd NOR does _not_ supports it. Please read the /drivers/mtd/maps/physmap_of.c and /drivers/mtd/chips/cfi_cmd_set_xxx.c. Of course, we can add the feature to NOR subsystem. But that's another issue. So the weim should enable the clock all the time now. > I guess it would also make sense to use of_platform_populate() instead > of of_platform_device_create() when creating the children, so we actually I tried the of_platform_populate(), but failed. firstly, we should set the timing for the device _before_ we do the of_platform_populate(). and i rewrite the weim_parse_dt() to: ------------------------------------------------------------------------------------------ static void weim_parse_dt(struct platform_device *pdev) { struct device_node *child; for_each_child_of_node(pdev->dev.of_node, child) { if (!child->name) continue; if (weim_timing_setup(pdev, child)) { dev_err(&pdev->dev, "%s set timing failed.\n", child->full_name); continue; } } if (!of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev)) dev_err(&pdev->dev, "%s device create failed.\n", child->full_name); } ------------------------------------------------------------------------------------------ The system hang at : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ## Booting kernel from Legacy Image at 10800000 ... Image Name: Linux Image Type: ARM Linux Kernel Image (uncompressed) Data Size: 4259851 Bytes = 4.1 MB Load Address: 10008000 Entry Point: 10008000 Verifying Checksum ... OK Loading Kernel Image ... OK OK Starting kernel ... ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++== thanks Huang Shijie From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Shijie Subject: Re: [PATCH V2 1/6] drivers: bus: add a new driver for WEIM Date: Fri, 24 May 2013 15:16:53 +0800 Message-ID: <519F13E5.2040701@freescale.com> References: <1369296978-7669-1-git-send-email-b32955@freescale.com> <201305231153.38111.arnd@arndb.de> <20130523115505.GG32299@pengutronix.de> <201305231509.57651.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <201305231509.57651.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Arnd Bergmann Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Sascha Hauer , rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, Alison_Chaiken-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org 5LqOIDIwMTPlubQwNeaciDIz5pelIDIxOjA5LCBBcm5kIEJlcmdtYW5uIOWGmemBkzoKPiBPVE9I LCBJIGFncmVlIHRoYXQgaXQgd291bGQgYmUgbmljZXIgaWYgdGhlIGNsayBjb3VsZCByZW1haW4g dHVybmVkCj4gb2ZmIGFzIGxvbmcgYXMgbm8gY2hpbGRyZW4gYXJlIGFjdGl2ZS4gQ2FuIHdlIGRv IGEgY2xrX2Rpc2FibGUoKQo+IGFmdGVyIHNldHRpbmcgdXAgdGhlIHRpbWluZ3MgZm9yIHRoZSBj aGlsZHJlbiBhbmQgdGhlbiBleHBlY3QgdGhvc2UKPiB0byBhY3R1YWxseSBzdGFydCB1cCB0aGUg Y2xrIGFnYWluIHdoZW4gdGhleSBuZWVkIGl0Pwo+Cj4gT3IgdG8gdGFrZSB0aGluZ3MgZnVydGhl cjogd291bGQgaXQgbWFrZSBzZW5zZSB0byByZXByZXNlbnQgV0VJTQo+IGl0c2VsZiBhcyBhIGNs b2NrIGRyaXZlciBhbmQgcGVyZm9ybSB0aGUgc2V0dGluZ3MgZm9yIGVhY2ggY2hpbGQKPiBvbmx5 IHdoZW4gaXQgc2V0cyB1cCBpdHMgb3duIGNsaz8KPgpJZiB0aGUgY2hpbGQncyBzdWJzeXN0ZW0g c3VwcG9ydHMgaXQsIHdlIGNhbiBkbyBpdC4KClRoZSBtdGQgbmFuZCBkb2VzIHN1cHBvcnQgdGhp cyBmZWF0dXJlLCBpdCBoYXMgQHNlbGVjdF9jaGlwKCkgaG9vay4KV2UgY2FuIGVuYWJsZS9kaXNh YmxlIHRoZSBjbG9jayBpbiB0aGUgQHNlbGVjdF9jaGlwKCkuCgpCdXQgdGhlIG10ZCBOT1IgZG9l cyBfbm90XyBzdXBwb3J0cyBpdC4KUGxlYXNlIHJlYWQgdGhlIC9kcml2ZXJzL210ZC9tYXBzL3Bo eXNtYXBfb2YuYyBhbmQgCi9kcml2ZXJzL210ZC9jaGlwcy9jZmlfY21kX3NldF94eHguYy4KT2Yg Y291cnNlLCB3ZSBjYW4gYWRkIHRoZSBmZWF0dXJlIHRvIE5PUiBzdWJzeXN0ZW0uIEJ1dCB0aGF0 J3MgYW5vdGhlciAKaXNzdWUuCgpTbyB0aGUgd2VpbSBzaG91bGQgZW5hYmxlIHRoZSBjbG9jayBh bGwgdGhlIHRpbWUgbm93LgoKCj4gSSBndWVzcyBpdCB3b3VsZCBhbHNvIG1ha2Ugc2Vuc2UgdG8g dXNlIG9mX3BsYXRmb3JtX3BvcHVsYXRlKCkgaW5zdGVhZAo+IG9mIG9mX3BsYXRmb3JtX2Rldmlj ZV9jcmVhdGUoKSB3aGVuIGNyZWF0aW5nIHRoZSBjaGlsZHJlbiwgc28gd2UgYWN0dWFsbHkKSSB0 cmllZCB0aGUgb2ZfcGxhdGZvcm1fcG9wdWxhdGUoKSwgYnV0IGZhaWxlZC4KCmZpcnN0bHksIHdl IHNob3VsZCBzZXQgdGhlIHRpbWluZyBmb3IgdGhlIGRldmljZSBfYmVmb3JlXyB3ZSBkbyB0aGUg Cm9mX3BsYXRmb3JtX3BvcHVsYXRlKCkuCmFuZCBpIHJld3JpdGUgdGhlIHdlaW1fcGFyc2VfZHQo KSB0bzoKLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tCnN0YXRpYyB2b2lkIHdlaW1f cGFyc2VfZHQoc3RydWN0IHBsYXRmb3JtX2RldmljZSAqcGRldikKewogICAgIHN0cnVjdCBkZXZp Y2Vfbm9kZSAqY2hpbGQ7CgogICAgIGZvcl9lYWNoX2NoaWxkX29mX25vZGUocGRldi0+ZGV2Lm9m X25vZGUsIGNoaWxkKSB7CiAgICAgICAgIGlmICghY2hpbGQtPm5hbWUpCiAgICAgICAgICAgICBj b250aW51ZTsKCiAgICAgICAgIGlmICh3ZWltX3RpbWluZ19zZXR1cChwZGV2LCBjaGlsZCkpIHsK ICAgICAgICAgICAgIGRldl9lcnIoJnBkZXYtPmRldiwgIiVzIHNldCB0aW1pbmcgZmFpbGVkLlxu IiwKICAgICAgICAgICAgICAgICBjaGlsZC0+ZnVsbF9uYW1lKTsKICAgICAgICAgICAgIGNvbnRp bnVlOwogICAgICAgICB9CgogICAgIH0KICAgICBpZiAoIW9mX3BsYXRmb3JtX3BvcHVsYXRlKHBk ZXYtPmRldi5vZl9ub2RlLCBOVUxMLCBOVUxMLCAmcGRldi0+ZGV2KSkKICAgICAgICAgZGV2X2Vy cigmcGRldi0+ZGV2LCAiJXMgZGV2aWNlIGNyZWF0ZSBmYWlsZWQuXG4iLAogICAgICAgICAgICAg Y2hpbGQtPmZ1bGxfbmFtZSk7Cn0KLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tCgpU aGUgc3lzdGVtIGhhbmcgYXQgOgorKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysr KysrKysrKysrKysrKysrKysrKysrKysrKysrKwoKIyMgQm9vdGluZyBrZXJuZWwgZnJvbSBMZWdh Y3kgSW1hZ2UgYXQgMTA4MDAwMDAgLi4uCiAgICBJbWFnZSBOYW1lOiAgIExpbnV4CiAgICBJbWFn ZSBUeXBlOiAgIEFSTSBMaW51eCBLZXJuZWwgSW1hZ2UgKHVuY29tcHJlc3NlZCkKICAgIERhdGEg U2l6ZTogICAgNDI1OTg1MSBCeXRlcyA9ICA0LjEgTUIKICAgIExvYWQgQWRkcmVzczogMTAwMDgw MDAKICAgIEVudHJ5IFBvaW50OiAgMTAwMDgwMDAKICAgIFZlcmlmeWluZyBDaGVja3N1bSAuLi4g T0sKICAgIExvYWRpbmcgS2VybmVsIEltYWdlIC4uLiBPSwpPSwoKU3RhcnRpbmcga2VybmVsIC4u LgorKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKysr KysrKysrKz09CgoKCnRoYW5rcwpIdWFuZyBTaGlqaWUKCgoKCl9fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fCmRldmljZXRyZWUtZGlzY3VzcyBtYWlsaW5nIGxp c3QKZGV2aWNldHJlZS1kaXNjdXNzQGxpc3RzLm96bGFicy5vcmcKaHR0cHM6Ly9saXN0cy5vemxh YnMub3JnL2xpc3RpbmZvL2RldmljZXRyZWUtZGlzY3Vzcwo=