From 18dbdda89f5cf0540e577280395f16079308e87d Mon Sep 17 00:00:00 2001 From: Dirk Brandewie Date: Thu, 6 Oct 2011 11:26:36 -0700 Subject: i2c-designware: Add runtime power management support Add runtime power management to the PCI driver. Signed-off-by: Dirk Brandewie Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-designware-core.c | 10 +++- drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-pcidrv.c | 89 ++++++++++++++++++++++++++++++ 3 files changed, 98 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index b9f18ddaaa7..df879924100 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include "i2c-designware-core.h" @@ -501,6 +502,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); mutex_lock(&dev->lock); + pm_runtime_get_sync(dev->dev); INIT_COMPLETION(dev->cmd_complete); dev->msgs = msgs; @@ -550,6 +552,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) ret = -EIO; done: + pm_runtime_put(dev->dev); mutex_unlock(&dev->lock); return ret; @@ -671,10 +674,13 @@ void i2c_dw_enable(struct dw_i2c_dev *dev) dw_writel(dev, 1, DW_IC_ENABLE); } -void i2c_dw_disable(struct dw_i2c_dev *dev) +u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev) { - int ret; + return dw_readl(dev, DW_IC_ENABLE); +} +void i2c_dw_disable(struct dw_i2c_dev *dev) +{ /* Disable controller */ dw_writel(dev, 0, DW_IC_ENABLE); diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 601dd67a6c2..02d1a2ddd85 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -98,6 +98,7 @@ extern int i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], extern u32 i2c_dw_func(struct i2c_adapter *adap); extern irqreturn_t i2c_dw_isr(int this_irq, void *dev_id); extern void i2c_dw_enable(struct dw_i2c_dev *dev); +extern u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev); extern void i2c_dw_disable(struct dw_i2c_dev *dev); extern void i2c_dw_clear_int(struct dw_i2c_dev *dev); extern void i2c_dw_disable_int(struct dw_i2c_dev *dev); diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c index 83307ef3b41..d2223b5f922 100644 --- a/drivers/i2c/busses/i2c-designware-pcidrv.c +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c @@ -38,6 +38,7 @@ #include #include #include +#include #include "i2c-designware-core.h" #define DRIVER_NAME "i2c-designware-pci" @@ -137,6 +138,82 @@ static struct i2c_algorithm i2c_dw_algo = { .functionality = i2c_dw_func, }; +static int i2c_dw_pci_suspend(struct pci_dev *pdev, pm_message_t mesg) +{ + struct dw_i2c_dev *i2c = pci_get_drvdata(pdev); + int err; + + + i2c_dw_disable(i2c); + + err = pci_save_state(pdev); + if (err) { + dev_err(&pdev->dev, "pci_save_state failed\n"); + return err; + } + + err = pci_set_power_state(pdev, PCI_D3hot); + if (err) { + dev_err(&pdev->dev, "pci_set_power_state failed\n"); + return err; + } + + return 0; +} + +static int i2c_dw_pci_runtime_suspend(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + dev_dbg(dev, "PCI suspend called\n"); + return i2c_dw_pci_suspend(pdev, PMSG_SUSPEND); +} + +static int i2c_dw_pci_resume(struct pci_dev *pdev) +{ + struct dw_i2c_dev *i2c = pci_get_drvdata(pdev); + int err; + u32 enabled; + + enabled = i2c_dw_is_enabled(i2c); + if (enabled) + return 0; + + err = pci_set_power_state(pdev, PCI_D0); + if (err) { + dev_err(&pdev->dev, "pci_set_power_state() failed\n"); + return err; + } + + pci_restore_state(pdev); + + i2c_dw_init(i2c); + i2c_dw_enable(i2c); + return 0; +} + +static int i2c_dw_pci_runtime_resume(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + dev_dbg(dev, "runtime_resume called\n"); + return i2c_dw_pci_resume(pdev); +} + +static int i2c_dw_pci_runtime_idle(struct device *dev) +{ + int err = pm_schedule_suspend(dev, 500); + dev_dbg(dev, "runtime_idle called\n"); + + if (err != 0) + return 0; + return -EBUSY; +} + +static const struct dev_pm_ops i2c_dw_pm_ops = { + .runtime_suspend = i2c_dw_pci_runtime_suspend, + .runtime_resume = i2c_dw_pci_runtime_resume, + .runtime_idle = i2c_dw_pci_runtime_idle, +}; + static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) { return dev->controller->clk_khz; @@ -245,6 +322,9 @@ const struct pci_device_id *id) goto err_free_irq; } + pm_runtime_put_noidle(&pdev->dev); + pm_runtime_allow(&pdev->dev); + return 0; err_free_irq: @@ -264,6 +344,10 @@ static void __devexit i2c_dw_pci_remove(struct pci_dev *pdev) { struct dw_i2c_dev *dev = pci_get_drvdata(pdev); + i2c_dw_disable(dev); + pm_runtime_forbid(&pdev->dev); + pm_runtime_get_noresume(&pdev->dev); + pci_set_drvdata(pdev, NULL); i2c_del_adapter(&dev->adapter); put_device(&pdev->dev); @@ -297,6 +381,11 @@ static struct pci_driver dw_i2c_driver = { .id_table = i2_designware_pci_ids, .probe = i2c_dw_pci_probe, .remove = __devexit_p(i2c_dw_pci_remove), + .resume = i2c_dw_pci_resume, + .suspend = i2c_dw_pci_suspend, + .driver = { + .pm = &i2c_dw_pm_ops, + }, }; static int __init dw_i2c_init_driver(void) -- cgit v1.2.3