This patch adds omap_device_scale API which can be used to generic device rate scaling.
Signed-off-by: Thara Gopinath <[email protected]> --- arch/arm/plat-omap/include/plat/omap_device.h | 3 +- arch/arm/plat-omap/omap_device.c | 78 +++++++++++++++++++++++++ 2 files changed, 80 insertions(+), 1 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h index 2a37345..daafb5a 100644 --- a/arch/arm/plat-omap/include/plat/omap_device.h +++ b/arch/arm/plat-omap/include/plat/omap_device.h @@ -116,6 +116,8 @@ unsigned long omap_device_get_rate(struct device *dev); void omap_device_populate_rate_fns(struct device *dev, int (*set_rate)(struct device *dev, unsigned long rate), unsigned long (*get_rate) (struct device *dev)); +int omap_device_scale(struct device *req_dev, struct device *dev, + unsigned long rate); /* Other */ @@ -125,7 +127,6 @@ int omap_device_enable_hwmods(struct omap_device *od); int omap_device_disable_clocks(struct omap_device *od); int omap_device_enable_clocks(struct omap_device *od); - /* * Entries should be kept in latency order ascending * diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c index ffe06eb..a273230 100644 --- a/arch/arm/plat-omap/omap_device.c +++ b/arch/arm/plat-omap/omap_device.c @@ -83,6 +83,7 @@ #include <linux/err.h> #include <linux/io.h> #include <linux/clk.h> +#include <linux/opp.h> #include <plat/omap_device.h> #include <plat/omap_hwmod.h> @@ -834,6 +835,83 @@ void omap_device_populate_rate_fns(struct device *dev, od->get_rate = get_rate; } +/** + * omap_device_scale() - Set a new rate at which the device is to operate + * @req_dev: pointer to the device requesting the scaling. + * @dev: pointer to the device that is to be scaled + * @rate: the rnew rate for the device. + * + * This API gets the device opp table associated with this device and + * tries putting the device to the requested rate and the voltage domain + * associated with the device to the voltage corresponding to the + * requested rate. Since multiple devices can be assocciated with a + * voltage domain this API finds out the possible voltage the + * voltage domain can enter and then decides on the final device + * rate. Return 0 on success else the error value + */ +int omap_device_scale(struct device *req_dev, struct device *dev, + unsigned long rate) +{ + struct opp *opp; + unsigned long volt, freq, min_freq, max_freq; + struct voltagedomain *voltdm; + struct platform_device *pdev; + struct omap_device *od; + int ret; + + pdev = container_of(dev, struct platform_device, dev); + od = _find_by_pdev(pdev); + + /* + * Figure out if the desired frquency lies between the + * maximum and minimum possible for the particular device + */ + min_freq = 0; + if (IS_ERR(opp_find_freq_ceil(dev, &min_freq))) { + dev_err(dev, "%s: Unable to find lowest opp\n", __func__); + return -ENODEV; + } + + max_freq = ULONG_MAX; + if (IS_ERR(opp_find_freq_floor(dev, &max_freq))) { + dev_err(dev, "%s: Unable to find highest opp\n", __func__); + return -ENODEV; + } + + if (rate < min_freq) + freq = min_freq; + else if (rate > max_freq) + freq = max_freq; + else + freq = rate; + + opp = opp_find_freq_ceil(dev, &freq); + if (IS_ERR(opp)) { + dev_err(dev, "%s: Unable to find OPP for freq%ld\n", + __func__, rate); + return -ENODEV; + } + + /* Get the voltage corresponding to the requested frequency */ + volt = opp_get_voltage(opp); + + /* + * Call into the voltage layer to get the final voltage possible + * for the voltage domain associated with the device. + */ + voltdm = od->hwmods[0]->voltdm; + ret = omap_voltage_add_request(voltdm, req_dev, &volt); + if (ret) { + dev_err(dev, "%s: Unable to get the final volt for scaling\n", + __func__); + return ret; + } + + /* Do the actual scaling */ + return omap_voltage_scale(voltdm, volt); +} +EXPORT_SYMBOL(omap_device_scale); + struct device omap_device_parent = { .init_name = "omap", .parent = &platform_bus, -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
