1 files changed, 49 insertions, 32 deletions

diff --git a/drivers/clk/ingenic/tcu.c b/drivers/clk/ingenic/tcu.c
index 77acfbeb4830..bc6a51da2072 100644
--- a/drivers/clk/ingenic/tcu.c
+++ b/drivers/clk/ingenic/tcu.c
@@ -31,6 +31,7 @@ struct ingenic_soc_info {
 	unsigned int num_channels;
 	bool has_ost;
 	bool has_tcu_clk;
+	bool allow_missing_tcu_clk;
 };
 
 struct ingenic_tcu_clk_info {
@@ -100,15 +101,11 @@ static bool ingenic_tcu_enable_regs(struct clk_hw *hw)
 	bool enabled = false;
 
 	/*
-	 * If the SoC has no global TCU clock, we must ungate the channel's
-	 * clock to be able to access its registers.
-	 * If we have a TCU clock, it will be enabled automatically as it has
-	 * been attached to the regmap.
+	 * According to the programming manual, a timer channel's registers can
+	 * only be accessed when the channel's stop bit is clear.
 	 */
-	if (!tcu->clk) {
-		enabled = !!ingenic_tcu_is_enabled(hw);
-		regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
-	}
+	enabled = !!ingenic_tcu_is_enabled(hw);
+	regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
 
 	return enabled;
 }
@@ -119,8 +116,7 @@ static void ingenic_tcu_disable_regs(struct clk_hw *hw)
 	const struct ingenic_tcu_clk_info *info = tcu_clk->info;
 	struct ingenic_tcu *tcu = tcu_clk->tcu;
 
-	if (!tcu->clk)
-		regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
+	regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
 }
 
 static u8 ingenic_tcu_get_parent(struct clk_hw *hw)
@@ -182,18 +178,21 @@ static u8 ingenic_tcu_get_prescale(unsigned long rate, unsigned long req_rate)
 	return 5; /* /1024 divider */
 }
 
-static long ingenic_tcu_round_rate(struct clk_hw *hw, unsigned long req_rate,
-		unsigned long *parent_rate)
+static int ingenic_tcu_determine_rate(struct clk_hw *hw,
+				      struct clk_rate_request *req)
 {
-	unsigned long rate = *parent_rate;
+	unsigned long rate = req->best_parent_rate;
 	u8 prescale;
 
-	if (req_rate > rate)
-		return rate;
+	if (req->rate > rate) {
+		req->rate = rate;
+		return 0;
+	}
 
-	prescale = ingenic_tcu_get_prescale(rate, req_rate);
+	prescale = ingenic_tcu_get_prescale(rate, req->rate);
 
-	return rate >> (prescale * 2);
+	req->rate = rate >> (prescale * 2);
+	return 0;
 }
 
 static int ingenic_tcu_set_rate(struct clk_hw *hw, unsigned long req_rate,
@@ -223,7 +222,7 @@ static const struct clk_ops ingenic_tcu_clk_ops = {
 	.set_parent	= ingenic_tcu_set_parent,
 
 	.recalc_rate	= ingenic_tcu_recalc_rate,
-	.round_rate	= ingenic_tcu_round_rate,
+	.determine_rate	= ingenic_tcu_determine_rate,
 	.set_rate	= ingenic_tcu_set_rate,
 
 	.enable		= ingenic_tcu_enable,
@@ -320,7 +319,8 @@ static const struct ingenic_soc_info jz4770_soc_info = {
 static const struct ingenic_soc_info x1000_soc_info = {
 	.num_channels = 8,
 	.has_ost = false, /* X1000 has OST, but it not belong TCU */
-	.has_tcu_clk = false,
+	.has_tcu_clk = true,
+	.allow_missing_tcu_clk = true,
 };
 
 static const struct of_device_id __maybe_unused ingenic_tcu_of_match[] __initconst = {
@@ -355,14 +355,27 @@ static int __init ingenic_tcu_probe(struct device_node *np)
 		tcu->clk = of_clk_get_by_name(np, "tcu");
 		if (IS_ERR(tcu->clk)) {
 			ret = PTR_ERR(tcu->clk);
-			pr_crit("Cannot get TCU clock\n");
-			goto err_free_tcu;
-		}
 
-		ret = clk_prepare_enable(tcu->clk);
-		if (ret) {
-			pr_crit("Unable to enable TCU clock\n");
-			goto err_put_clk;
+			/*
+			 * Old device trees for some SoCs did not include the
+			 * TCU clock because this driver (incorrectly) didn't
+			 * use it. In this case we complain loudly and attempt
+			 * to continue without the clock, which might work if
+			 * booting with workarounds like "clk_ignore_unused".
+			 */
+			if (tcu->soc_info->allow_missing_tcu_clk && ret == -EINVAL) {
+				pr_warn("TCU clock missing from device tree, please update your device tree\n");
+				tcu->clk = NULL;
+			} else {
+				pr_crit("Cannot get TCU clock from device tree\n");
+				goto err_free_tcu;
+			}
+		} else {
+			ret = clk_prepare_enable(tcu->clk);
+			if (ret) {
+				pr_crit("Unable to enable TCU clock\n");
+				goto err_put_clk;
+			}
 		}
 	}
 
@@ -432,17 +445,17 @@ err_unregister_timer_clocks:
 			clk_hw_unregister(tcu->clocks->hws[i]);
 	kfree(tcu->clocks);
 err_clk_disable:
-	if (tcu->soc_info->has_tcu_clk)
+	if (tcu->clk)
 		clk_disable_unprepare(tcu->clk);
 err_put_clk:
-	if (tcu->soc_info->has_tcu_clk)
+	if (tcu->clk)
 		clk_put(tcu->clk);
 err_free_tcu:
 	kfree(tcu);
 	return ret;
 }
 
-static int __maybe_unused tcu_pm_suspend(void)
+static int __maybe_unused tcu_pm_suspend(void *data)
 {
 	struct ingenic_tcu *tcu = ingenic_tcu;
 
@@ -452,7 +465,7 @@ static int __maybe_unused tcu_pm_suspend(void)
 	return 0;
 }
 
-static void __maybe_unused tcu_pm_resume(void)
+static void __maybe_unused tcu_pm_resume(void *data)
 {
 	struct ingenic_tcu *tcu = ingenic_tcu;
 
@@ -460,11 +473,15 @@ static void __maybe_unused tcu_pm_resume(void)
 		clk_enable(tcu->clk);
 }
 
-static struct syscore_ops __maybe_unused tcu_pm_ops = {
+static const struct syscore_ops __maybe_unused tcu_pm_ops = {
 	.suspend = tcu_pm_suspend,
 	.resume = tcu_pm_resume,
 };
 
+static struct syscore __maybe_unused tcu_pm = {
+	.ops = &tcu_pm_ops,
+};
+
 static void __init ingenic_tcu_init(struct device_node *np)
 {
 	int ret = ingenic_tcu_probe(np);
@@ -473,7 +490,7 @@ static void __init ingenic_tcu_init(struct device_node *np)
 		pr_crit("Failed to initialize TCU clocks: %d\n", ret);
 
 	if (IS_ENABLED(CONFIG_PM_SLEEP))
-		register_syscore_ops(&tcu_pm_ops);
+		register_syscore(&tcu_pm);
 }
 
 CLK_OF_DECLARE_DRIVER(jz4740_cgu, "ingenic,jz4740-tcu", ingenic_tcu_init);