From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: [PATCH 5/6] i2c: davinci: Add cpufreq support Date: Tue, 26 Jan 2010 15:41:32 -0800 Message-ID: <1264549293-25556-6-git-send-email-khilman@deeprootsystems.com> References: <1264549293-25556-1-git-send-email-khilman@deeprootsystems.com> Return-path: In-Reply-To: <1264549293-25556-1-git-send-email-khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ben Dooks Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org, Chaithrika U S List-Id: linux-i2c@vger.kernel.org From: Chaithrika U S Add cpufreq support for DaVinci I2C driver. Tested on DA850/OMAP-L138 EVM. For the purpose of testing, the patches which add cpufreq support [1] for this SoC are needed. [1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/ 2009-September/016118.html Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 63 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 63 insertions(+), 0 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 66b07bf..35f9daa 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -106,6 +107,10 @@ struct davinci_i2c_dev { int stop; u8 terminate; struct i2c_adapter adapter; +#ifdef CONFIG_CPU_FREQ + struct completion xfr_complete; + struct notifier_block freq_transition; +#endif }; /* default platform data to use if not supplied in the platform_device */ @@ -388,6 +393,11 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) if (ret < 0) return ret; } + +#ifdef CONFIG_CPU_FREQ + complete(&dev->xfr_complete); +#endif + return num; } @@ -520,6 +530,48 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) return count ? IRQ_HANDLED : IRQ_NONE; } +#ifdef CONFIG_CPU_FREQ +static int i2c_davinci_cpufreq_transition(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct davinci_i2c_dev *dev; + + dev = container_of(nb, struct davinci_i2c_dev, freq_transition); + if (val == CPUFREQ_PRECHANGE) { + wait_for_completion(&dev->xfr_complete); + davinci_i2c_reset_ctrl(dev, 0); + } else if (val == CPUFREQ_POSTCHANGE) { + i2c_davinci_calc_clk_dividers(dev); + davinci_i2c_reset_ctrl(dev, 1); + } + + return 0; +} + +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition; + + return cpufreq_register_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ + cpufreq_unregister_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} +#else +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + return 0; +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ +} +#endif + static struct i2c_algorithm i2c_davinci_algo = { .master_xfer = i2c_davinci_xfer, .functionality = i2c_davinci_func, @@ -559,6 +611,9 @@ static int davinci_i2c_probe(struct platform_device *pdev) } init_completion(&dev->cmd_complete); +#ifdef CONFIG_CPU_FREQ + init_completion(&dev->xfr_complete); +#endif dev->dev = get_device(&pdev->dev); dev->irq = irq->start; platform_set_drvdata(pdev, dev); @@ -584,6 +639,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) goto err_unuse_clocks; } + r = i2c_davinci_cpufreq_register(dev); + if (r) { + dev_err(&pdev->dev, "failed to register cpufreq\n"); + goto err_free_irq; + } + adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; @@ -625,6 +686,8 @@ static int davinci_i2c_remove(struct platform_device *pdev) struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); struct resource *mem; + i2c_davinci_cpufreq_deregister(dev); + platform_set_drvdata(pdev, NULL); i2c_del_adapter(&dev->adapter); put_device(&pdev->dev); -- 1.6.6