2019-09-19 14:43:19 +00:00
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From 1a5122f1756ef4fc5779324ad26b6a04142166b5 Mon Sep 17 00:00:00 2001
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2019-07-09 18:32:28 +00:00
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From: Annaliese McDermond <nh6z@nh6z.net>
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Date: Fri, 21 Jun 2019 03:52:50 -0700
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2019-12-23 12:42:55 +00:00
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Subject: [PATCH] i2c: bcm2835: Ensure clock exists when probing
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2019-07-09 18:32:28 +00:00
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Commit 9de93b04df16b055824e3f1f13fedb90fbcf2e4f upstream.
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Probe function fails to recognize that upstream clock actually
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doesn't yet exist because clock driver has not been initialized.
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Actually try to go get the clock and test for its existence
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before trying to set up a downstream clock based upon it.
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This fixes a bug that causes the i2c driver not to work with
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monolithic kernels.
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Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF")
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Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
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Acked-by: Stefan Wahren <wahrenst@gmx.net>
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Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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---
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drivers/i2c/busses/i2c-bcm2835.c | 16 ++++++++++++----
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1 file changed, 12 insertions(+), 4 deletions(-)
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--- a/drivers/i2c/busses/i2c-bcm2835.c
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+++ b/drivers/i2c/busses/i2c-bcm2835.c
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@@ -244,15 +244,18 @@ static const struct clk_ops clk_bcm2835_
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};
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static struct clk *bcm2835_i2c_register_div(struct device *dev,
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- const char *mclk_name,
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+ struct clk *mclk,
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struct bcm2835_i2c_dev *i2c_dev)
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{
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struct clk_init_data init;
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struct clk_bcm2835_i2c *priv;
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char name[32];
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+ const char *mclk_name;
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snprintf(name, sizeof(name), "%s_div", dev_name(dev));
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+ mclk_name = __clk_get_name(mclk);
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+
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init.ops = &clk_bcm2835_i2c_ops;
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init.name = name;
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init.parent_names = (const char* []) { mclk_name };
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@@ -505,8 +508,8 @@ static int bcm2835_i2c_probe(struct plat
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struct resource *mem, *irq;
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int ret;
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struct i2c_adapter *adap;
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- const char *mclk_name;
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struct clk *bus_clk;
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+ struct clk *mclk;
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u32 bus_clk_rate;
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i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
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@@ -521,9 +524,14 @@ static int bcm2835_i2c_probe(struct plat
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if (IS_ERR(i2c_dev->regs))
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return PTR_ERR(i2c_dev->regs);
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- mclk_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
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+ mclk = devm_clk_get(&pdev->dev, NULL);
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+ if (IS_ERR(mclk)) {
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+ if (PTR_ERR(mclk) != -EPROBE_DEFER)
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+ dev_err(&pdev->dev, "Could not get clock\n");
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+ return PTR_ERR(mclk);
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+ }
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- bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk_name, i2c_dev);
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+ bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
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if (IS_ERR(bus_clk)) {
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dev_err(&pdev->dev, "Could not register clock\n");
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