clk: x86: Do not gate clocks enabled by the firmware

Carlo Caione · bebarino · commit d31fd43c0f9a · 2017-07-18T16:23:13.000-07:00
Read the enable register to determine if the clock is already in use by the firmware. In this case avoid gating the clock. Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Darren Hart (VMware) <dvhart@infradead.org> Signed-off-by: Carlo Caione <carlo@endlessm.com> Fixes: 282a4e4 ("platform/x86: Enable Atom PMC platform clocks") Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/x86/clk-pmc-atom.c b/drivers/clk/x86/clk-pmc-atom.c
@@ -186,6 +186,13 @@ static struct clk_plt *plt_clk_register(struct platform_device *pdev, int id,
 	pclk->reg = base + PMC_CLK_CTL_OFFSET + id * PMC_CLK_CTL_SIZE;
 	spin_lock_init(&pclk->lock);
 
+	/*
+	 * If the clock was already enabled by the firmware mark it as critical
+	 * to avoid it being gated by the clock framework if no driver owns it.
+	 */
+	if (plt_clk_is_enabled(&pclk->hw))
+		init.flags |= CLK_IS_CRITICAL;
+
 	ret = devm_clk_hw_register(&pdev->dev, &pclk->hw);
 	if (ret) {
 		pclk = ERR_PTR(ret);
