From a20d23945f30ec701a544fdd90d6537f4041af6f Mon Sep 17 00:00:00 2001 From: Jonas Aberg Date: Fri, 13 May 2011 12:29:02 +0200 Subject: i2c-nomadik: add regulator support This on-chip I2C controller needs to fetch the regulator representing its voltage domain so that it won't be switched off. Signed-off-by: Jonas Aberg Signed-off-by: Linus Walleij Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-nomadik.c | 73 +++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 15 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index e10e5cf..182761e 100644 --- a/drivers/i2c/busses/i2c-nomadik.c +++ b/drivers/i2c/busses/i2c-nomadik.c @@ -22,6 +22,7 @@ #include #include #include +#include #include @@ -151,6 +152,7 @@ struct i2c_nmk_client { * @stop: stop condition * @xfer_complete: acknowledge completion for a I2C message * @result: controller propogated result + * @busy: Busy doing transfer */ struct nmk_i2c_dev { struct platform_device *pdev; @@ -163,6 +165,8 @@ struct nmk_i2c_dev { int stop; struct completion xfer_complete; int result; + struct regulator *regulator; + bool busy; }; /* controller's abort causes */ @@ -257,7 +261,7 @@ static int init_hw(struct nmk_i2c_dev *dev) stat = flush_i2c_fifo(dev); if (stat) - return stat; + goto exit; /* disable the controller */ i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE); @@ -268,10 +272,16 @@ static int init_hw(struct nmk_i2c_dev *dev) dev->cli.operation = I2C_NO_OPERATION; +exit: + /* TODO: Why disable clocks after init hw? */ clk_disable(dev->clk); - + /* + * TODO: What is this delay for? + * Must be pretty pointless since the hw block + * is frozen. Or? + */ udelay(I2C_DELAY); - return 0; + return stat; } /* enable peripheral, master mode operation */ @@ -562,9 +572,14 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, u32 cause; struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap); + dev->busy = true; + + if (dev->regulator) + regulator_enable(dev->regulator); + status = init_hw(dev); if (status) - return status; + goto out2; clk_enable(dev->clk); @@ -575,7 +590,9 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, if (unlikely(msgs[i].flags & I2C_M_TEN)) { dev_err(&dev->pdev->dev, "10 bit addressing" "not supported\n"); - return -EINVAL; + + status = -EINVAL; + goto out; } dev->cli.slave_adr = msgs[i].addr; dev->cli.buffer = msgs[i].buf; @@ -600,12 +617,19 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, dev_err(&dev->pdev->dev, "%s\n", cause >= ARRAY_SIZE(abort_causes) ? "unknown reason" : abort_causes[cause]); - clk_disable(dev->clk); - return status; + + goto out; } udelay(I2C_DELAY); } + +out: clk_disable(dev->clk); +out2: + if (dev->regulator) + regulator_disable(dev->regulator); + + dev->busy = false; /* return the no. messages processed */ if (status) @@ -805,6 +829,21 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) return IRQ_HANDLED; } + +#ifdef CONFIG_PM +static int nmk_i2c_suspend(struct platform_device *pdev, pm_message_t mesg) +{ + struct nmk_i2c_dev *dev = platform_get_drvdata(pdev); + + if (dev->busy) + return -EBUSY; + else + return 0; +} +#else +#define nmk_i2c_suspend NULL +#endif + static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; @@ -830,7 +869,7 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev) ret = -ENOMEM; goto err_no_mem; } - + dev->busy = false; dev->pdev = pdev; platform_set_drvdata(pdev, dev); @@ -860,6 +899,12 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev) goto err_irq; } + dev->regulator = regulator_get(&pdev->dev, "v-i2c"); + if (IS_ERR(dev->regulator)) { + dev_warn(&pdev->dev, "could not get i2c regulator\n"); + dev->regulator = NULL; + } + dev->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(dev->clk)) { dev_err(&pdev->dev, "could not get i2c clock\n"); @@ -887,12 +932,6 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev) i2c_set_adapdata(adap, dev); - ret = init_hw(dev); - if (ret != 0) { - dev_err(&pdev->dev, "error in initializing i2c hardware\n"); - goto err_init_hw; - } - dev_info(&pdev->dev, "initialize %s on virtual " "base %p\n", adap->name, dev->virtbase); @@ -904,10 +943,11 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev) return 0; - err_init_hw: err_add_adap: clk_put(dev->clk); err_no_clk: + if (dev->regulator) + regulator_put(dev->regulator); free_irq(dev->irq, dev); err_irq: iounmap(dev->virtbase); @@ -938,6 +978,8 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev) if (res) release_mem_region(res->start, resource_size(res)); clk_put(dev->clk); + if (dev->regulator) + regulator_put(dev->regulator); platform_set_drvdata(pdev, NULL); kfree(dev); @@ -951,6 +993,7 @@ static struct platform_driver nmk_i2c_driver = { }, .probe = nmk_i2c_probe, .remove = __devexit_p(nmk_i2c_remove), + .suspend = nmk_i2c_suspend, }; static int __init nmk_i2c_init(void) -- cgit v1.1