4.19-stable review patch. If anyone has any objections, please let me know.
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From: Nuno Sa nuno.sa@analog.com
[ Upstream commit c64ef7e4851d1a9abbb7f7833e4936973ac5ba79 ]
In order to access the registers of the HW, we need to make sure that the AXI bus clock is enabled. Hence let's increase the number of clocks by one.
In order to keep backward compatibility and make sure old DTs still work we check if clock-names is available or not. If it is, then we can disambiguate between really having the AXI clock or a parent clock and so we can enable the bus clock. If not, we fallback to what was done before and don't explicitly enable the AXI bus clock.
Note that if clock-names is given, the axi clock must be the last one in the phandle array (also enforced in the DT bindings) so that we can reuse as much code as possible.
Fixes: 0e646c52cf0e ("clk: Add axi-clkgen driver") Signed-off-by: Nuno Sa nuno.sa@analog.com Link: https://lore.kernel.org/r/20241029-axi-clkgen-fix-axiclk-v2-2-bc5e0733ad76@a... Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/clk-axi-clkgen.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c index 7289da51b74f1..f1e276ce28d46 100644 --- a/drivers/clk/clk-axi-clkgen.c +++ b/drivers/clk/clk-axi-clkgen.c @@ -9,6 +9,7 @@ */
#include <linux/platform_device.h> +#include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/slab.h> #include <linux/io.h> @@ -414,6 +415,7 @@ static int axi_clkgen_probe(struct platform_device *pdev) struct clk_init_data init; const char *parent_names[2]; const char *clk_name; + struct clk *axi_clk; unsigned int i; int ret;
@@ -433,8 +435,24 @@ static int axi_clkgen_probe(struct platform_device *pdev) return PTR_ERR(axi_clkgen->base);
init.num_parents = of_clk_get_parent_count(pdev->dev.of_node); - if (init.num_parents < 1 || init.num_parents > 2) - return -EINVAL; + + axi_clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk"); + if (!IS_ERR(axi_clk)) { + if (init.num_parents < 2 || init.num_parents > 3) + return -EINVAL; + + init.num_parents -= 1; + } else { + /* + * Legacy... So that old DTs which do not have clock-names still + * work. In this case we don't explicitly enable the AXI bus + * clock. + */ + if (PTR_ERR(axi_clk) != -ENOENT) + return PTR_ERR(axi_clk); + if (init.num_parents < 1 || init.num_parents > 2) + return -EINVAL; + }
for (i = 0; i < init.num_parents; i++) { parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i);