Commit 697ad249 authored by Sam Protsenko's avatar Sam Protsenko Committed by Wolfram Sang
Browse files

i2c: exynos5: Add bus clock support 



In new Exynos SoCs (like Exynos850) where HSI2C is implemented as a
part of USIv2 block, there are two clocks provided to HSI2C controller:
  - PCLK: bus clock (APB), provides access to register interface
  - IPCLK: operating IP-core clock; SCL is derived from this one

Both clocks have to be asserted for HSI2C to be functional in that case.

Add code to obtain and enable/disable PCLK in addition to already
handled operating clock. Make it optional though, as older Exynos SoC
variants only have one HSI2C clock.

Signed-off-by: default avatarSam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: default avatarChanho Park <chanho61.park@samsung.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 3f689102

drivers/i2c/busses/i2c-exynos5.c

+38 −8
Original line number Diff line number Diff line
@@ -182,7 +182,8 @@ struct exynos5_i2c { 
	unsigned int		irq;



	void __iomem		*regs;

	struct clk		*clk;

	struct clk		*clk;		/* operating clock */

	struct clk		*pclk;		/* bus clock */

	struct device		*dev;

	int			state;
@@ -757,10 +758,14 @@ static int exynos5_i2c_xfer(struct i2c_adapter *adap, 
	struct exynos5_i2c *i2c = adap->algo_data;

	int i, ret;



	ret = clk_enable(i2c->clk);

	ret = clk_enable(i2c->pclk);

	if (ret)

		return ret;



	ret = clk_enable(i2c->clk);

	if (ret)

		goto err_pclk;



	for (i = 0; i < num; ++i) {

		ret = exynos5_i2c_xfer_msg(i2c, msgs + i, i + 1 == num);

		if (ret)
@@ -768,6 +773,8 @@ static int exynos5_i2c_xfer(struct i2c_adapter *adap, 
	}



	clk_disable(i2c->clk);

err_pclk:

	clk_disable(i2c->pclk);



	return ret ?: num;

}
@@ -807,10 +814,18 @@ static int exynos5_i2c_probe(struct platform_device *pdev) 
		return -ENOENT;

	}



	ret = clk_prepare_enable(i2c->clk);

	i2c->pclk = devm_clk_get(&pdev->dev, "hsi2c_pclk");

	if (IS_ERR(i2c->pclk))

		i2c->pclk = NULL; /* pclk is optional */



	ret = clk_prepare_enable(i2c->pclk);

	if (ret)

		return ret;



	ret = clk_prepare_enable(i2c->clk);

	if (ret)

		goto err_pclk;



	i2c->regs = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(i2c->regs)) {

		ret = PTR_ERR(i2c->regs);
@@ -853,11 +868,15 @@ static int exynos5_i2c_probe(struct platform_device *pdev) 
	platform_set_drvdata(pdev, i2c);



	clk_disable(i2c->clk);

	clk_disable(i2c->pclk);



	return 0;



 err_clk:

	clk_disable_unprepare(i2c->clk);



 err_pclk:

	clk_disable_unprepare(i2c->pclk);

	return ret;

}
@@ -868,6 +887,7 @@ static int exynos5_i2c_remove(struct platform_device *pdev) 
	i2c_del_adapter(&i2c->adap);



	clk_unprepare(i2c->clk);

	clk_unprepare(i2c->pclk);



	return 0;

}
@@ -879,6 +899,7 @@ static int exynos5_i2c_suspend_noirq(struct device *dev) 


	i2c_mark_adapter_suspended(&i2c->adap);

	clk_unprepare(i2c->clk);

	clk_unprepare(i2c->pclk);



	return 0;

}
@@ -888,21 +909,30 @@ static int exynos5_i2c_resume_noirq(struct device *dev) 
	struct exynos5_i2c *i2c = dev_get_drvdata(dev);

	int ret = 0;



	ret = clk_prepare_enable(i2c->clk);

	ret = clk_prepare_enable(i2c->pclk);

	if (ret)

		return ret;



	ret = clk_prepare_enable(i2c->clk);

	if (ret)

		goto err_pclk;



	ret = exynos5_hsi2c_clock_setup(i2c);

	if (ret) {

		clk_disable_unprepare(i2c->clk);

		return ret;

	}

	if (ret)

		goto err_clk;



	exynos5_i2c_init(i2c);

	clk_disable(i2c->clk);

	clk_disable(i2c->pclk);

	i2c_mark_adapter_resumed(&i2c->adap);



	return 0;



err_clk:

	clk_disable_unprepare(i2c->clk);

err_pclk:

	clk_disable_unprepare(i2c->pclk);

	return ret;

}

#endif