From 697ad2490c96981ec12b0a6d3c7c26fbad80e1e8 Mon Sep 17 00:00:00 2001 From: Sam Protsenko Date: Thu, 9 Dec 2021 16:03:13 +0200 Subject: 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: Sam Protsenko Reviewed-by: Krzysztof Kozlowski Reviewed-by: Chanho Park Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-exynos5.c | 46 +++++++++++++++++++++++++++++++++------- 1 file changed, 38 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c index c7e3cae99d13..693903e80892 100644 --- a/drivers/i2c/busses/i2c-exynos5.c +++ b/drivers/i2c/busses/i2c-exynos5.c @@ -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 -- cgit v1.2.3