From cc4e8c3dc95369c08615a4151bce8506b00356d9 Mon Sep 17 00:00:00 2001 From: Sifan Naeem Date: Wed, 4 Feb 2015 13:48:14 -0300 Subject: [PATCH] [media] rc: img-ir: Add and enable sys clock for img-ir Gets a handle to the system clock, already described in the binding document, and calls the appropriate common clock framework functions to mark it prepared/enabled, the common clock framework initially enables the clock and doesn't disable it at least until the device/driver is removed. It's important the systen clock is enabled before register interface is accessed by the driver. The system clock to IR is needed for the driver to communicate with the IR hardware via MMIO accesses on the system bus, so it must not be disabled during use or the driver will malfunction. Signed-off-by: Sifan Naeem Acked-by: James Hogan Signed-off-by: Mauro Carvalho Chehab --- drivers/media/rc/img-ir/img-ir-core.c | 29 +++++++++++++++++++++++---- drivers/media/rc/img-ir/img-ir.h | 2 ++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/media/rc/img-ir/img-ir-core.c b/drivers/media/rc/img-ir/img-ir-core.c index 77c78de4f5bf..a10d66600ce4 100644 --- a/drivers/media/rc/img-ir/img-ir-core.c +++ b/drivers/media/rc/img-ir/img-ir-core.c @@ -110,16 +110,32 @@ static int img_ir_probe(struct platform_device *pdev) priv->clk = devm_clk_get(&pdev->dev, "core"); if (IS_ERR(priv->clk)) dev_warn(&pdev->dev, "cannot get core clock resource\n"); + + /* Get sys clock */ + priv->sys_clk = devm_clk_get(&pdev->dev, "sys"); + if (IS_ERR(priv->sys_clk)) + dev_warn(&pdev->dev, "cannot get sys clock resource\n"); /* - * The driver doesn't need to know about the system ("sys") or power - * modulation ("mod") clocks yet + * Enabling the system clock before the register interface is + * accessed. ISR shouldn't get called with Sys Clock disabled, + * hence exiting probe with an error. */ + if (!IS_ERR(priv->sys_clk)) { + error = clk_prepare_enable(priv->sys_clk); + if (error) { + dev_err(&pdev->dev, "cannot enable sys clock\n"); + return error; + } + } /* Set up raw & hw decoder */ error = img_ir_probe_raw(priv); error2 = img_ir_probe_hw(priv); - if (error && error2) - return (error == -ENODEV) ? error2 : error; + if (error && error2) { + if (error == -ENODEV) + error = error2; + goto err_probe; + } /* Get the IRQ */ priv->irq = irq; @@ -139,6 +155,9 @@ static int img_ir_probe(struct platform_device *pdev) err_irq: img_ir_remove_hw(priv); img_ir_remove_raw(priv); +err_probe: + if (!IS_ERR(priv->sys_clk)) + clk_disable_unprepare(priv->sys_clk); return error; } @@ -152,6 +171,8 @@ static int img_ir_remove(struct platform_device *pdev) if (!IS_ERR(priv->clk)) clk_disable_unprepare(priv->clk); + if (!IS_ERR(priv->sys_clk)) + clk_disable_unprepare(priv->sys_clk); return 0; } diff --git a/drivers/media/rc/img-ir/img-ir.h b/drivers/media/rc/img-ir/img-ir.h index 2ddf56083182..f1387c016d3d 100644 --- a/drivers/media/rc/img-ir/img-ir.h +++ b/drivers/media/rc/img-ir/img-ir.h @@ -138,6 +138,7 @@ struct clk; * @dev: Platform device. * @irq: IRQ number. * @clk: Input clock. + * @sys_clk: System clock. * @reg_base: Iomem base address of IR register block. * @lock: Protects IR registers and variables in this struct. * @raw: Driver data for raw decoder. @@ -147,6 +148,7 @@ struct img_ir_priv { struct device *dev; int irq; struct clk *clk; + struct clk *sys_clk; void __iomem *reg_base; spinlock_t lock; -- 2.39.5