bus: ti-sysc: Add support for module specific reset quirks

Some older interconnect target modules need module internal clock
toggling quirks to reset properly. We've been doing this in the
platform code earlier, but need to be able to it directly in the
ti-sysc driver when we no longer rely on on the platform code.

Let's add reset handling for 1-wire, i2c and watchdog. Later on
we can add more modules like msdi and dss as they get tested.
For dra7 pcie, we should be able to just use the rstctrl reset
driver when available.
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/bus/ti-sysc.c

@@ -71,6 +71,9 @@ static const char * const clock_names[SYSC_MAX_CLOCKS] = {
  * @name: name if available
  * @revision: interconnect target module revision
  * @needs_resume: runtime resume needed on resume from suspend
+ * @clk_enable_quirk: module specific clock enable quirk
+ * @clk_disable_quirk: module specific clock disable quirk
+ * @reset_done_quirk: module specific reset done quirk
  */
 struct sysc {
 	struct device *dev;
@@ -94,6 +97,9 @@ struct sysc {
 	unsigned int child_needs_resume:1;
 	unsigned int disable_on_idle:1;
 	struct delayed_work idle_work;
+	void (*clk_enable_quirk)(struct sysc *sysc);
+	void (*clk_disable_quirk)(struct sysc *sysc);
+	void (*reset_done_quirk)(struct sysc *sysc);
 };
 
 static void sysc_parse_dts_quirks(struct sysc *ddata, struct device_node *np,
@@ -760,8 +766,11 @@ static int sysc_ioremap(struct sysc *ddata)
 			    ddata->offsets[SYSC_SYSCONFIG],
 			    ddata->offsets[SYSC_SYSSTATUS]);
 
+		if (size < SZ_1K)
+			size = SZ_1K;
+
 		if ((size + sizeof(u32)) > ddata->module_size)
-			return -EINVAL;
+			size = ddata->module_size;
 	}
 
 	ddata->module_va = devm_ioremap(ddata->dev,
@@ -1234,6 +1243,22 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = {
 		   SYSC_QUIRK_EXT_OPT_CLOCK | SYSC_QUIRK_NO_RESET_ON_INIT |
 		   SYSC_QUIRK_SWSUP_SIDLE),
 
+	/* Quirks that need to be set based on detected module */
+	SYSC_QUIRK("hdq1w", 0, 0, 0x14, 0x18, 0x00000006, 0xffffffff,
+		   SYSC_MODULE_QUIRK_HDQ1W),
+	SYSC_QUIRK("hdq1w", 0, 0, 0x14, 0x18, 0x0000000a, 0xffffffff,
+		   SYSC_MODULE_QUIRK_HDQ1W),
+	SYSC_QUIRK("i2c", 0, 0, 0x20, 0x10, 0x00000036, 0x000000ff,
+		   SYSC_MODULE_QUIRK_I2C),
+	SYSC_QUIRK("i2c", 0, 0, 0x20, 0x10, 0x0000003c, 0x000000ff,
+		   SYSC_MODULE_QUIRK_I2C),
+	SYSC_QUIRK("i2c", 0, 0, 0x20, 0x10, 0x00000040, 0x000000ff,
+		   SYSC_MODULE_QUIRK_I2C),
+	SYSC_QUIRK("i2c", 0, 0, 0x10, 0x90, 0x5040000a, 0xfffff0f0,
+		   SYSC_MODULE_QUIRK_I2C),
+	SYSC_QUIRK("wdt", 0, 0, 0x10, 0x14, 0x502a0500, 0xfffff0f0,
+		   SYSC_MODULE_QUIRK_WDT),
+
 #ifdef DEBUG
 	SYSC_QUIRK("adc", 0, 0, 0x10, -1, 0x47300001, 0xffffffff, 0),
 	SYSC_QUIRK("atl", 0, 0, -1, -1, 0x0a070100, 0xffffffff, 0),
@@ -1247,11 +1272,8 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = {
 	SYSC_QUIRK("dwc3", 0, 0, 0x10, -1, 0x500a0200, 0xffffffff, 0),
 	SYSC_QUIRK("epwmss", 0, 0, 0x4, -1, 0x47400001, 0xffffffff, 0),
 	SYSC_QUIRK("gpu", 0, 0x1fc00, 0x1fc10, -1, 0, 0, 0),
-	SYSC_QUIRK("hdq1w", 0, 0, 0x14, 0x18, 0x00000006, 0xffffffff, 0),
-	SYSC_QUIRK("hdq1w", 0, 0, 0x14, 0x18, 0x0000000a, 0xffffffff, 0),
 	SYSC_QUIRK("hsi", 0, 0, 0x10, 0x14, 0x50043101, 0xffffffff, 0),
 	SYSC_QUIRK("iss", 0, 0, 0x10, -1, 0x40000101, 0xffffffff, 0),
-	SYSC_QUIRK("i2c", 0, 0, 0x10, 0x90, 0x5040000a, 0xfffff0f0, 0),
 	SYSC_QUIRK("lcdc", 0, 0, 0x54, -1, 0x4f201000, 0xffffffff, 0),
 	SYSC_QUIRK("mcasp", 0, 0, 0x4, -1, 0x44306302, 0xffffffff, 0),
 	SYSC_QUIRK("mcasp", 0, 0, 0x4, -1, 0x44307b02, 0xffffffff, 0),
@@ -1287,7 +1309,6 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = {
 	SYSC_QUIRK("usb_host_hs", 0, 0, 0x10, -1, 0x50700101, 0xffffffff, 0),
 	SYSC_QUIRK("usb_otg_hs", 0, 0x400, 0x404, 0x408, 0x00000050,
 		   0xffffffff, 0),
-	SYSC_QUIRK("wdt", 0, 0, 0x10, 0x14, 0x502a0500, 0xfffff0f0, 0),
 	SYSC_QUIRK("vfpe", 0, 0, 0x104, -1, 0x4d001200, 0xffffffff, 0),
 #endif
 };
@@ -1360,6 +1381,94 @@ static void sysc_init_revision_quirks(struct sysc *ddata)
 	}
 }
 
+/* 1-wire needs module's internal clocks enabled for reset */
+static void sysc_clk_enable_quirk_hdq1w(struct sysc *ddata)
+{
+	int offset = 0x0c;	/* HDQ_CTRL_STATUS */
+	u16 val;
+
+	val = sysc_read(ddata, offset);
+	val |= BIT(5);
+	sysc_write(ddata, offset, val);
+}
+
+/* I2C needs extra enable bit toggling for reset */
+static void sysc_clk_quirk_i2c(struct sysc *ddata, bool enable)
+{
+	int offset;
+	u16 val;
+
+	/* I2C_CON, omap2/3 is different from omap4 and later */
+	if ((ddata->revision & 0xffffff00) == 0x001f0000)
+		offset = 0x24;
+	else
+		offset = 0xa4;
+
+	/* I2C_EN */
+	val = sysc_read(ddata, offset);
+	if (enable)
+		val |= BIT(15);
+	else
+		val &= ~BIT(15);
+	sysc_write(ddata, offset, val);
+}
+
+static void sysc_clk_enable_quirk_i2c(struct sysc *ddata)
+{
+	sysc_clk_quirk_i2c(ddata, true);
+}
+
+static void sysc_clk_disable_quirk_i2c(struct sysc *ddata)
+{
+	sysc_clk_quirk_i2c(ddata, false);
+}
+
+/* Watchdog timer needs a disable sequence after reset */
+static void sysc_reset_done_quirk_wdt(struct sysc *ddata)
+{
+	int wps, spr, error;
+	u32 val;
+
+	wps = 0x34;
+	spr = 0x48;
+
+	sysc_write(ddata, spr, 0xaaaa);
+	error = readl_poll_timeout(ddata->module_va + wps, val,
+				   !(val & 0x10), 100,
+				   MAX_MODULE_SOFTRESET_WAIT);
+	if (error)
+		dev_warn(ddata->dev, "wdt disable spr failed\n");
+
+	sysc_write(ddata, wps, 0x5555);
+	error = readl_poll_timeout(ddata->module_va + wps, val,
+				   !(val & 0x10), 100,
+				   MAX_MODULE_SOFTRESET_WAIT);
+	if (error)
+		dev_warn(ddata->dev, "wdt disable wps failed\n");
+}
+
+static void sysc_init_module_quirks(struct sysc *ddata)
+{
+	if (ddata->legacy_mode || !ddata->name)
+		return;
+
+	if (ddata->cfg.quirks & SYSC_MODULE_QUIRK_HDQ1W) {
+		ddata->clk_enable_quirk = sysc_clk_enable_quirk_hdq1w;
+
+		return;
+	}
+
+	if (ddata->cfg.quirks & SYSC_MODULE_QUIRK_I2C) {
+		ddata->clk_enable_quirk = sysc_clk_enable_quirk_i2c;
+		ddata->clk_disable_quirk = sysc_clk_disable_quirk_i2c;
+
+		return;
+	}
+
+	if (ddata->cfg.quirks & SYSC_MODULE_QUIRK_WDT)
+		ddata->reset_done_quirk = sysc_reset_done_quirk_wdt;
+}
+
 static int sysc_clockdomain_init(struct sysc *ddata)
 {
 	struct ti_sysc_platform_data *pdata = dev_get_platdata(ddata->dev);
@@ -1468,10 +1577,16 @@ static int sysc_reset(struct sysc *ddata)
 	else
 		syss_done = ddata->cfg.syss_mask;
 
+	if (ddata->clk_disable_quirk)
+		ddata->clk_disable_quirk(ddata);
+
 	sysc_val = sysc_read_sysconfig(ddata);
 	sysc_val |= sysc_mask;
 	sysc_write(ddata, sysc_offset, sysc_val);
 
+	if (ddata->clk_enable_quirk)
+		ddata->clk_enable_quirk(ddata);
+
 	/* Poll on reset status */
 	if (syss_offset >= 0) {
 		error = readx_poll_timeout(sysc_read_sysstatus, ddata, rstval,
@@ -1485,6 +1600,9 @@ static int sysc_reset(struct sysc *ddata)
 					   100, MAX_MODULE_SOFTRESET_WAIT);
 	}
 
+	if (ddata->reset_done_quirk)
+		ddata->reset_done_quirk(ddata);
+
 	return error;
 }
 
@@ -1531,6 +1649,7 @@ static int sysc_init_module(struct sysc *ddata)
 
 	ddata->revision = sysc_read_revision(ddata);
 	sysc_init_revision_quirks(ddata);
+	sysc_init_module_quirks(ddata);
 
 	if (ddata->legacy_mode) {
 		error = sysc_legacy_init(ddata);

include/linux/platform_data/ti-sysc.h

@@ -47,6 +47,9 @@ struct sysc_regbits {
 	s8 emufree_shift;
 };
 
+#define SYSC_MODULE_QUIRK_HDQ1W		BIT(17)
+#define SYSC_MODULE_QUIRK_I2C		BIT(16)
+#define SYSC_MODULE_QUIRK_WDT		BIT(15)
 #define SYSS_QUIRK_RESETDONE_INVERTED	BIT(14)
 #define SYSC_QUIRK_SWSUP_MSTANDBY	BIT(13)
 #define SYSC_QUIRK_SWSUP_SIDLE_ACT	BIT(12)