bus: ti-sysc: Add support for missing clockdomain handling

We need to let ti-sysc driver manage clockdomain autoidle for the
duration of of reset, enable and idle. And we need to do it before we
enable the clock and after we disable it. Currently we are still
relying on platform callbacks indirectly managing clockdomain autoidle.
But I noticed that for device tree only probed drivers it now happens
only after we enabling the clocks and before we disable the clocks,
while it should be the other way around. So far I have not noticed
any issues with this though.

Let's add new ti_sysc_clkdm_deny_idle() and ti_sysc_clkdm_allow_idle()
functions for ti-sysc driver to use to manage clockdomains directly via
platform data callbacks. Note that we can implement the clockdomain
functions in pdata-quirks.c as for probing devices without "ti,hwmods"
custom property we don't need to use the other platform data callbacks.

Let's do this in one patch as there's is still an unlikely chance we
may need to apply this as a fix for v5.2 for dropping legacy platform
data for some devices. We also do have the option of adding back the
platform data if needed in case of trouble.

Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 101 insertions, 26 deletions

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
index b72741668c92..e86f7850206a 100644
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -422,6 +422,30 @@ static void sysc_disable_opt_clocks(struct sysc *ddata)
 	}
 }
 
+static void sysc_clkdm_deny_idle(struct sysc *ddata)
+{
+	struct ti_sysc_platform_data *pdata;
+
+	if (ddata->legacy_mode)
+		return;
+
+	pdata = dev_get_platdata(ddata->dev);
+	if (pdata && pdata->clkdm_deny_idle)
+		pdata->clkdm_deny_idle(ddata->dev, &ddata->cookie);
+}
+
+static void sysc_clkdm_allow_idle(struct sysc *ddata)
+{
+	struct ti_sysc_platform_data *pdata;
+
+	if (ddata->legacy_mode)
+		return;
+
+	pdata = dev_get_platdata(ddata->dev);
+	if (pdata && pdata->clkdm_allow_idle)
+		pdata->clkdm_allow_idle(ddata->dev, &ddata->cookie);
+}
+
 /**
  * sysc_init_resets - init rstctrl reset line if configured
  * @ddata: device driver data
@@ -795,6 +819,7 @@ static void sysc_show_registers(struct sysc *ddata)
 
 #define SYSC_IDLE_MASK	(SYSC_NR_IDLEMODES - 1)
 
+/* Caller needs to manage sysc_clkdm_deny_idle() and sysc_clkdm_allow_idle() */
 static int sysc_enable_module(struct device *dev)
 {
 	struct sysc *ddata;
@@ -805,11 +830,6 @@ static int sysc_enable_module(struct device *dev)
 	if (ddata->offsets[SYSC_SYSCONFIG] == -ENODEV)
 		return 0;
 
-	/*
-	 * TODO: Need to prevent clockdomain autoidle?
-	 * See clkdm_deny_idle() in arch/mach-omap2/omap_hwmod.c
-	 */
-
 	regbits = ddata->cap->regbits;
 	reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
 
@@ -861,6 +881,7 @@ static int sysc_best_idle_mode(u32 idlemodes, u32 *best_mode)
 	return 0;
 }
 
+/* Caller needs to manage sysc_clkdm_deny_idle() and sysc_clkdm_allow_idle() */
 static int sysc_disable_module(struct device *dev)
 {
 	struct sysc *ddata;
@@ -872,11 +893,6 @@ static int sysc_disable_module(struct device *dev)
 	if (ddata->offsets[SYSC_SYSCONFIG] == -ENODEV)
 		return 0;
 
-	/*
-	 * TODO: Need to prevent clockdomain autoidle?
-	 * See clkdm_deny_idle() in arch/mach-omap2/omap_hwmod.c
-	 */
-
 	regbits = ddata->cap->regbits;
 	reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
 
@@ -966,14 +982,16 @@ static int __maybe_unused sysc_runtime_suspend(struct device *dev)
 	if (!ddata->enabled)
 		return 0;
 
+	sysc_clkdm_deny_idle(ddata);
+
 	if (ddata->legacy_mode) {
 		error = sysc_runtime_suspend_legacy(dev, ddata);
 		if (error)
-			return error;
+			goto err_allow_idle;
 	} else {
 		error = sysc_disable_module(dev);
 		if (error)
-			return error;
+			goto err_allow_idle;
 	}
 
 	sysc_disable_main_clocks(ddata);
@@ -983,6 +1001,9 @@ static int __maybe_unused sysc_runtime_suspend(struct device *dev)
 
 	ddata->enabled = false;
 
+err_allow_idle:
+	sysc_clkdm_allow_idle(ddata);
+
 	return error;
 }
 
@@ -996,10 +1017,12 @@ static int __maybe_unused sysc_runtime_resume(struct device *dev)
 	if (ddata->enabled)
 		return 0;
 
+	sysc_clkdm_deny_idle(ddata);
+
 	if (sysc_opt_clks_needed(ddata)) {
 		error = sysc_enable_opt_clocks(ddata);
 		if (error)
-			return error;
+			goto err_allow_idle;
 	}
 
 	error = sysc_enable_main_clocks(ddata);
@@ -1018,6 +1041,8 @@ static int __maybe_unused sysc_runtime_resume(struct device *dev)
 
 	ddata->enabled = true;
 
+	sysc_clkdm_allow_idle(ddata);
+
 	return 0;
 
 err_main_clocks:
@@ -1025,6 +1050,8 @@ err_main_clocks:
 err_opt_clocks:
 	if (sysc_opt_clks_needed(ddata))
 		sysc_disable_opt_clocks(ddata);
+err_allow_idle:
+	sysc_clkdm_allow_idle(ddata);
 
 	return error;
 }
@@ -1245,6 +1272,33 @@ static void sysc_init_revision_quirks(struct sysc *ddata)
 	}
 }
 
+static int sysc_clockdomain_init(struct sysc *ddata)
+{
+	struct ti_sysc_platform_data *pdata = dev_get_platdata(ddata->dev);
+	struct clk *fck = NULL, *ick = NULL;
+	int error;
+
+	if (!pdata || !pdata->init_clockdomain)
+		return 0;
+
+	switch (ddata->nr_clocks) {
+	case 2:
+		ick = ddata->clocks[SYSC_ICK];
+		/* fallthrough */
+	case 1:
+		fck = ddata->clocks[SYSC_FCK];
+		break;
+	case 0:
+		return 0;
+	}
+
+	error = pdata->init_clockdomain(ddata->dev, fck, ick, &ddata->cookie);
+	if (!error || error == -ENODEV)
+		return 0;
+
+	return error;
+}
+
 /*
  * Note that pdata->init_module() typically does a reset first. After
  * pdata->init_module() is done, PM runtime can be used for the interconnect
@@ -1255,7 +1309,7 @@ static int sysc_legacy_init(struct sysc *ddata)
 	struct ti_sysc_platform_data *pdata = dev_get_platdata(ddata->dev);
 	int error;
 
-	if (!ddata->legacy_mode || !pdata || !pdata->init_module)
+	if (!pdata || !pdata->init_module)
 		return 0;
 
 	error = pdata->init_module(ddata->dev, ddata->mdata, &ddata->cookie);
@@ -1347,7 +1401,13 @@ static int sysc_init_module(struct sysc *ddata)
 	    (SYSC_QUIRK_NO_IDLE | SYSC_QUIRK_NO_IDLE_ON_INIT))
 		manage_clocks = false;
 
+	error = sysc_clockdomain_init(ddata);
+	if (error)
+		return error;
+
 	if (manage_clocks) {
+		sysc_clkdm_deny_idle(ddata);
+
 		error = sysc_enable_opt_clocks(ddata);
 		if (error)
 			return error;
@@ -1360,20 +1420,33 @@ static int sysc_init_module(struct sysc *ddata)
 	ddata->revision = sysc_read_revision(ddata);
 	sysc_init_revision_quirks(ddata);
 
-	error = sysc_legacy_init(ddata);
-	if (error)
-		goto err_main_clocks;
+	if (ddata->legacy_mode) {
+		error = sysc_legacy_init(ddata);
+		if (error)
+			goto err_main_clocks;
+	}
+
+	if (!ddata->legacy_mode && manage_clocks) {
+		error = sysc_enable_module(ddata->dev);
+		if (error)
+			goto err_main_clocks;
+	}
 
 	error = sysc_reset(ddata);
 	if (error)
 		dev_err(ddata->dev, "Reset failed with %d\n", error);
 
+	if (!ddata->legacy_mode && manage_clocks)
+		sysc_disable_module(ddata->dev);
+
 err_main_clocks:
 	if (manage_clocks)
 		sysc_disable_main_clocks(ddata);
 err_opt_clocks:
-	if (manage_clocks)
+	if (manage_clocks) {
 		sysc_disable_opt_clocks(ddata);
+		sysc_clkdm_allow_idle(ddata);
+	}
 
 	return error;
 }
@@ -2012,20 +2085,22 @@ static int sysc_init_pdata(struct sysc *ddata)
 	struct ti_sysc_platform_data *pdata = dev_get_platdata(ddata->dev);
 	struct ti_sysc_module_data *mdata;
 
-	if (!pdata || !ddata->legacy_mode)
+	if (!pdata)
 		return 0;
 
 	mdata = devm_kzalloc(ddata->dev, sizeof(*mdata), GFP_KERNEL);
 	if (!mdata)
 		return -ENOMEM;
 
-	mdata->name = ddata->legacy_mode;
-	mdata->module_pa = ddata->module_pa;
-	mdata->module_size = ddata->module_size;
-	mdata->offsets = ddata->offsets;
-	mdata->nr_offsets = SYSC_MAX_REGS;
-	mdata->cap = ddata->cap;
-	mdata->cfg = &ddata->cfg;
+	if (ddata->legacy_mode) {
+		mdata->name = ddata->legacy_mode;
+		mdata->module_pa = ddata->module_pa;
+		mdata->module_size = ddata->module_size;
+		mdata->offsets = ddata->offsets;
+		mdata->nr_offsets = SYSC_MAX_REGS;
+		mdata->cap = ddata->cap;
+		mdata->cfg = &ddata->cfg;
+	}
 
 	ddata->mdata = mdata;