On Thu, Jul 21, 2011 at 5:52 PM, Kevin Hilman <khilman@xxxxxx> wrote:
> Rather than embedding a struct platform_device inside a struct
> omap_device, decouple them, leaving only a pointer to the
> platform_device inside the omap_device.
>
> This patch uses devres to allocate and attach the omap_device to the
> struct device, so finding an omap_device from a struct device means
> using devres_find(), and the to_omap_device() helper function was
> modified accordingly.
>
> RFC/Hack alert:
>
> Currently the driver core (drivers/base/dd.c) doesn't expect any
> devres resources to exist before the driver's ->probe() is called. In
> this patch, I just comment out the warning, but we'll need to
> understand why that limitation exists, and if it's a real limitation.
> A first glance suggests that it's not really needed. If this is a
> true limitation, we'll need to find some way other than devres to
> attach an omap_device to a struct device.
The devres lifetime is scoped to binding a driver; it is added at
probe time and removed at release. For this use-case, it needs to be
scoped to the lifetime of the struct device. To make this work,
you'll need to add a flag to devres so that the driver core can
differentiate between driver-scoped and device-scoped lifetimes (which
I do think is the right thing to do). Without fixing this, the driver
core will remove all the devres when a driver gets unbound, or if a
.probe() hook fails, which completely breaks the driver model.
g.
>
> On OMAP, we will need an omap_device attached to a struct device
> before probe because device HW may be disabled in probe and drivers
> are expected to use runtime PM in ->probe() to activate the hardware
> before access. Because the runtime PM API calls use omap_device (via
> our PM domain layer), we need omap_device attached to a
> platform_device before probe.
> ---
> arch/arm/mach-omap2/opp.c | 2 +-
> arch/arm/plat-omap/include/plat/omap_device.h | 4 +-
> arch/arm/plat-omap/omap_device.c | 78 +++++++++++++++----------
> drivers/base/dd.c | 2 +-
> 4 files changed, 50 insertions(+), 36 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/opp.c b/arch/arm/mach-omap2/opp.c
> index ab8b35b..9262a6b 100644
> --- a/arch/arm/mach-omap2/opp.c
> +++ b/arch/arm/mach-omap2/opp.c
> @@ -69,7 +69,7 @@ int __init omap_init_opp_table(struct omap_opp_def *opp_def,
> opp_def->hwmod_name, i);
> return -EINVAL;
> }
> - dev = &oh->od->pdev.dev;
> + dev = &oh->od->pdev->dev;
>
> r = opp_add(dev, opp_def->freq, opp_def->u_volt);
> if (r) {
> diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
> index 7a3ec4f..6bd4f6f 100644
> --- a/arch/arm/plat-omap/include/plat/omap_device.h
> +++ b/arch/arm/plat-omap/include/plat/omap_device.h
> @@ -64,7 +64,7 @@ extern struct device omap_device_parent;
> *
> */
> struct omap_device {
> - struct platform_device pdev;
> + struct platform_device *pdev;
> struct omap_hwmod **hwmods;
> struct omap_device_pm_latency *pm_lats;
> u32 dev_wakeup_lat;
> @@ -142,6 +142,6 @@ struct omap_device_pm_latency {
> #define OMAP_DEVICE_LATENCY_AUTO_ADJUST BIT(1)
>
> /* Get omap_device pointer from platform_device pointer */
> -#define to_omap_device(x) container_of((x), struct omap_device, pdev)
> +struct omap_device *to_omap_device(struct platform_device *pdev);
>
> #endif
> diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
> index c420b94..52ce013 100644
> --- a/arch/arm/plat-omap/omap_device.c
> +++ b/arch/arm/plat-omap/omap_device.c
> @@ -117,7 +117,7 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
> {
> struct timespec a, b, c;
>
> - dev_dbg(&od->pdev.dev, "omap_device: activating\n");
> + dev_dbg(&od->pdev->dev, "omap_device: activating\n");
>
> while (od->pm_lat_level > 0) {
> struct omap_device_pm_latency *odpl;
> @@ -141,7 +141,7 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
> c = timespec_sub(b, a);
> act_lat = timespec_to_ns(&c);
>
> - dev_dbg(&od->pdev.dev,
> + dev_dbg(&od->pdev->dev,
> "omap_device: pm_lat %d: activate: elapsed time "
> "%llu nsec\n", od->pm_lat_level, act_lat);
>
> @@ -149,12 +149,12 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
> odpl->activate_lat_worst = act_lat;
> if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
> odpl->activate_lat = act_lat;
> - dev_warn(&od->pdev.dev,
> + dev_warn(&od->pdev->dev,
> "new worst case activate latency "
> "%d: %llu\n",
> od->pm_lat_level, act_lat);
> } else
> - dev_warn(&od->pdev.dev,
> + dev_warn(&od->pdev->dev,
> "activate latency %d "
> "higher than exptected. (%llu > %d)\n",
> od->pm_lat_level, act_lat,
> @@ -185,7 +185,7 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
> {
> struct timespec a, b, c;
>
> - dev_dbg(&od->pdev.dev, "omap_device: deactivating\n");
> + dev_dbg(&od->pdev->dev, "omap_device: deactivating\n");
>
> while (od->pm_lat_level < od->pm_lats_cnt) {
> struct omap_device_pm_latency *odpl;
> @@ -208,7 +208,7 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
> c = timespec_sub(b, a);
> deact_lat = timespec_to_ns(&c);
>
> - dev_dbg(&od->pdev.dev,
> + dev_dbg(&od->pdev->dev,
> "omap_device: pm_lat %d: deactivate: elapsed time "
> "%llu nsec\n", od->pm_lat_level, deact_lat);
>
> @@ -216,12 +216,12 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
> odpl->deactivate_lat_worst = deact_lat;
> if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
> odpl->deactivate_lat = deact_lat;
> - dev_warn(&od->pdev.dev,
> + dev_warn(&od->pdev->dev,
> "new worst case deactivate latency "
> "%d: %llu\n",
> od->pm_lat_level, deact_lat);
> } else
> - dev_warn(&od->pdev.dev,
> + dev_warn(&od->pdev->dev,
> "deactivate latency %d "
> "higher than exptected. (%llu > %d)\n",
> od->pm_lat_level, deact_lat,
> @@ -245,11 +245,11 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias,
> if (!clk_alias || !clk_name)
> return;
>
> - dev_dbg(&od->pdev.dev, "Creating %s -> %s\n", clk_alias, clk_name);
> + dev_dbg(&od->pdev->dev, "Creating %s -> %s\n", clk_alias, clk_name);
>
> - r = clk_get_sys(dev_name(&od->pdev.dev), clk_alias);
> + r = clk_get_sys(dev_name(&od->pdev->dev), clk_alias);
> if (!IS_ERR(r)) {
> - dev_warn(&od->pdev.dev,
> + dev_warn(&od->pdev->dev,
> "alias %s already exists\n", clk_alias);
> clk_put(r);
> return;
> @@ -257,14 +257,14 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias,
>
> r = omap_clk_get_by_name(clk_name);
> if (IS_ERR(r)) {
> - dev_err(&od->pdev.dev,
> + dev_err(&od->pdev->dev,
> "omap_clk_get_by_name for %s failed\n", clk_name);
> return;
> }
>
> - l = clkdev_alloc(r, clk_alias, dev_name(&od->pdev.dev));
> + l = clkdev_alloc(r, clk_alias, dev_name(&od->pdev->dev));
> if (!l) {
> - dev_err(&od->pdev.dev,
> + dev_err(&od->pdev->dev,
> "clkdev_alloc for %s failed\n", clk_alias);
> return;
> }
> @@ -351,7 +351,7 @@ static int omap_device_count_resources(struct omap_device *od)
> c += omap_hwmod_count_resources(od->hwmods[i]);
>
> pr_debug("omap_device: %s: counted %d total resources across %d "
> - "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
> + "hwmods\n", od->pdev->name, c, od->hwmods_cnt);
>
> return c;
> }
> @@ -388,6 +388,21 @@ static int omap_device_fill_resources(struct omap_device *od,
> return 0;
> }
>
> +static void _od_dr_release(struct device *dev, void *res)
> +{
> + kfree(res);
> +}
> +
> +struct omap_device *to_omap_device(struct platform_device *pdev)
> +{
> + void *res;
> +
> + res = devres_find(&pdev->dev, _od_dr_release, NULL, NULL);
> + WARN_ON(!res);
> +
> + return (struct omap_device *)res;
> +}
> +
> /**
> * omap_device_build - build and register an omap_device with one omap_hwmod
> * @pdev_name: name of the platform_device driver to use
> @@ -445,8 +460,8 @@ struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
> int pm_lats_cnt, int is_early_device)
> {
> int ret = -ENOMEM;
> + struct platform_device *pdev;
> struct omap_device *od;
> - char *pdev_name2;
> struct resource *res = NULL;
> int i, res_count;
> struct omap_hwmod **hwmods;
> @@ -460,7 +475,8 @@ struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
> pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
> oh_cnt);
>
> - od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
> + od = devres_alloc(_od_dr_release, sizeof(struct omap_device),
> + GFP_KERNEL);
> if (!od)
> return ERR_PTR(-ENOMEM);
>
> @@ -474,13 +490,9 @@ struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
> memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
> od->hwmods = hwmods;
>
> - pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
> - if (!pdev_name2)
> + pdev = platform_device_alloc(pdev_name, pdev_id);
> + if (!pdev)
> goto odbs_exit2;
> - strcpy(pdev_name2, pdev_name);
> -
> - od->pdev.name = pdev_name2;
> - od->pdev.id = pdev_id;
>
> res_count = omap_device_count_resources(od);
> if (res_count > 0) {
> @@ -490,35 +502,37 @@ struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
> }
> omap_device_fill_resources(od, res);
>
> - od->pdev.num_resources = res_count;
> - od->pdev.resource = res;
> + pdev->num_resources = res_count;
> + pdev->resource = res;
>
> - ret = platform_device_add_data(&od->pdev, pdata, pdata_len);
> + ret = platform_device_add_data(pdev, pdata, pdata_len);
> if (ret)
> goto odbs_exit4;
>
> od->pm_lats = pm_lats;
> od->pm_lats_cnt = pm_lats_cnt;
>
> - if (is_early_device)
> - ret = omap_early_device_register(&od->pdev);
> - else
> - ret = omap_device_register(&od->pdev);
> + od->pdev = pdev;
> + devres_add(&pdev->dev, od);
>
> for (i = 0; i < oh_cnt; i++) {
> hwmods[i]->od = od;
> _add_hwmod_clocks_clkdev(od, hwmods[i]);
> }
>
> + if (is_early_device)
> + ret = omap_early_device_register(pdev);
> + else
> + ret = omap_device_register(pdev);
> +
> if (ret)
> goto odbs_exit4;
>
> - return &od->pdev;
> + return pdev;
>
> odbs_exit4:
> kfree(res);
> odbs_exit3:
> - kfree(pdev_name2);
> odbs_exit2:
> kfree(hwmods);
> odbs_exit1:
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 6658da7..9289dac 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -112,7 +112,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> atomic_inc(&probe_count);
> pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
> drv->bus->name, __func__, drv->name, dev_name(dev));
> - WARN_ON(!list_empty(&dev->devres_head));
> + /* WARN_ON(!list_empty(&dev->devres_head)); */
>
> dev->driver = drv;
> if (driver_sysfs_add(dev)) {
> --
> 1.7.6
>
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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