| Message ID | 1365549721-15620-1-git-send-email-khilman@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tuesday, April 09, 2013 04:22:01 PM Kevin Hilman wrote: > From: Nishanth Menon <nm@ti.com> > > As multi-platform build is being adopted by more and more ARM platforms, > initcall function should be used very carefully. For example, when > CONFIG_ARM_OMAP2PLUS_CPUFREQ is built in the kernel, omap_cpufreq_init() > will be called on all the platforms to initialize omap-cpufreq driver. > > Further, on OMAP, we now use Soc generic cpufreq-cpu0 driver using device > tree entries. To allow cpufreq-cpu0 and omap-cpufreq drivers to co-exist > for OMAP in a single image, we need to ensure the following: > 1. With device tree boot, we use cpufreq-cpu0 > 2. With non device tree boot, we use omap-cpufreq > > In the case of (1), we will have cpu OPPs and regulator registered > as part of the device tree nodes, to ensure that omap-cpufreq > and cpufreq-cpu0 don't conflict in managing the frequency of the > same CPU, we should not permit omap-cpufreq to be probed. > > In the case of (2), we will not have the cpufreq-cpu0 device, hence > only omap-cpufreq will be active. > > To eliminate this undesired these effects, we change omap-cpufreq > driver to have it instantiated as a platform_driver and register > "omap-cpufreq" device only when booted without device tree nodes on > OMAP platforms. > > This allows the following: > a) Will only run on platforms that create the platform_device > "omap-cpufreq". > b) Since the platform_device is registered only when device tree nodes > are *not* populated, omap-cpufreq driver does not conflict with > the usage of cpufreq-cpu0 driver which is used on OMAP platforms when > device tree nodes are present. > > Inspired by commit 5553f9e26f6f49a93ba732fd222eac6973a4cf35 > (cpufreq: instantiate cpufreq-cpu0 as a platform_driver) > > Cc: Kevin Hilman <khilman@linaro.org> > Cc: Rajendra Nayak <rnayak@ti.com> > Cc: Paul Walmsley <paul@pwsan.com> > Cc: "Benoît Cousson" <b-cousson@ti.com> > Cc: Jon Hunter <jon-hunter@ti.com> > Cc: Keerthy <j-keerthy@ti.com> > Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> > Cc: Shawn Guo <shawn.guo@linaro.org> > [robherring2@gmail.com: reported conflict of omap-cpufreq vs other > driver in an non-device tree supported boot] > Reported-by: Rob Herring <robherring2@gmail.com> > Signed-off-by: Nishanth Menon <nm@ti.com> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > Signed-off-by: Kevin Hilman <khilman@linaro.org> > --- > Rafael, can you add this one for v3.10? It applies on top the > rest of your cpufreq changes and I've verified that the OMAP > changes are OK and don't conflict with anything else we have > queued for v3.10 on OMAP. > > This patch was previously part of a 2-patch series, but the > other part is still in discussion, and this part can be merged > independently. Applied to my bleeding-edge branch and will go to linux-next after build testing. Thanks, Rafael > arch/arm/mach-omap2/pm.c | 9 +++++++++ > drivers/cpufreq/omap-cpufreq.c | 19 ++++++++++++++----- > 2 files changed, 23 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c > index 673a4c1..8d15f9a 100644 > --- a/arch/arm/mach-omap2/pm.c > +++ b/arch/arm/mach-omap2/pm.c > @@ -265,6 +265,12 @@ static void __init omap4_init_voltages(void) > omap2_set_init_voltage("iva", "dpll_iva_m5x2_ck", "iva"); > } > > +static inline void omap_init_cpufreq(void) > +{ > + struct platform_device_info devinfo = { .name = "omap-cpufreq", }; > + platform_device_register_full(&devinfo); > +} > + > static int __init omap2_common_pm_init(void) > { > if (!of_have_populated_dt()) > @@ -294,6 +300,9 @@ int __init omap2_common_pm_late_init(void) > > /* Smartreflex device init */ > omap_devinit_smartreflex(); > + > + /* cpufreq dummy device instantiation */ > + omap_init_cpufreq(); > } > > #ifdef CONFIG_SUSPEND > diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c > index 9128c07..d4f84b8 100644 > --- a/drivers/cpufreq/omap-cpufreq.c > +++ b/drivers/cpufreq/omap-cpufreq.c > @@ -25,6 +25,7 @@ > #include <linux/opp.h> > #include <linux/cpu.h> > #include <linux/module.h> > +#include <linux/platform_device.h> > #include <linux/regulator/consumer.h> > > #include <asm/smp_plat.h> > @@ -252,7 +253,7 @@ static struct cpufreq_driver omap_driver = { > .attr = omap_cpufreq_attr, > }; > > -static int __init omap_cpufreq_init(void) > +static int omap_cpufreq_probe(struct platform_device *pdev) > { > mpu_dev = get_cpu_device(0); > if (!mpu_dev) { > @@ -280,12 +281,20 @@ static int __init omap_cpufreq_init(void) > return cpufreq_register_driver(&omap_driver); > } > > -static void __exit omap_cpufreq_exit(void) > +static int omap_cpufreq_remove(struct platform_device *pdev) > { > - cpufreq_unregister_driver(&omap_driver); > + return cpufreq_unregister_driver(&omap_driver); > } > > +static struct platform_driver omap_cpufreq_platdrv = { > + .driver = { > + .name = "omap-cpufreq", > + .owner = THIS_MODULE, > + }, > + .probe = omap_cpufreq_probe, > + .remove = omap_cpufreq_remove, > +}; > +module_platform_driver(omap_cpufreq_platdrv); > + > MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs"); > MODULE_LICENSE("GPL"); > -module_init(omap_cpufreq_init); > -module_exit(omap_cpufreq_exit); >
diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c index 673a4c1..8d15f9a 100644 --- a/arch/arm/mach-omap2/pm.c +++ b/arch/arm/mach-omap2/pm.c @@ -265,6 +265,12 @@ static void __init omap4_init_voltages(void) omap2_set_init_voltage("iva", "dpll_iva_m5x2_ck", "iva"); } +static inline void omap_init_cpufreq(void) +{ + struct platform_device_info devinfo = { .name = "omap-cpufreq", }; + platform_device_register_full(&devinfo); +} + static int __init omap2_common_pm_init(void) { if (!of_have_populated_dt()) @@ -294,6 +300,9 @@ int __init omap2_common_pm_late_init(void) /* Smartreflex device init */ omap_devinit_smartreflex(); + + /* cpufreq dummy device instantiation */ + omap_init_cpufreq(); } #ifdef CONFIG_SUSPEND diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c index 9128c07..d4f84b8 100644 --- a/drivers/cpufreq/omap-cpufreq.c +++ b/drivers/cpufreq/omap-cpufreq.c @@ -25,6 +25,7 @@ #include <linux/opp.h> #include <linux/cpu.h> #include <linux/module.h> +#include <linux/platform_device.h> #include <linux/regulator/consumer.h> #include <asm/smp_plat.h> @@ -252,7 +253,7 @@ static struct cpufreq_driver omap_driver = { .attr = omap_cpufreq_attr, }; -static int __init omap_cpufreq_init(void) +static int omap_cpufreq_probe(struct platform_device *pdev) { mpu_dev = get_cpu_device(0); if (!mpu_dev) { @@ -280,12 +281,20 @@ static int __init omap_cpufreq_init(void) return cpufreq_register_driver(&omap_driver); } -static void __exit omap_cpufreq_exit(void) +static int omap_cpufreq_remove(struct platform_device *pdev) { - cpufreq_unregister_driver(&omap_driver); + return cpufreq_unregister_driver(&omap_driver); } +static struct platform_driver omap_cpufreq_platdrv = { + .driver = { + .name = "omap-cpufreq", + .owner = THIS_MODULE, + }, + .probe = omap_cpufreq_probe, + .remove = omap_cpufreq_remove, +}; +module_platform_driver(omap_cpufreq_platdrv); + MODULE_DESCRIPTION("cpufreq driver for OMAP SoCs"); MODULE_LICENSE("GPL"); -module_init(omap_cpufreq_init); -module_exit(omap_cpufreq_exit);