[v3,net-next] net: ethernet: ti: davinci_mdio: Add workaround for errata i2329

diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index ea3772618043..946b9753ccfb 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -26,6 +26,8 @@ 
 #include <linux/of_device.h>
 #include <linux/of_mdio.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/mdio-bitbang.h>
+#include <linux/sys_soc.h>
 
 /*
  * This timeout definition is a worst-case ultra defensive measure against
@@ -41,6 +43,7 @@ 
 
 struct davinci_mdio_of_param {
 	int autosuspend_delay_ms;
+	bool manual_mode;
 };
 
 struct davinci_mdio_regs {
@@ -49,6 +52,15 @@  struct davinci_mdio_regs {
 #define CONTROL_IDLE		BIT(31)
 #define CONTROL_ENABLE		BIT(30)
 #define CONTROL_MAX_DIV		(0xffff)
+#define CONTROL_CLKDIV		GENMASK(15, 0)
+
+#define MDIO_MAN_MDCLK_O	BIT(2)
+#define MDIO_MAN_OE		BIT(1)
+#define MDIO_MAN_PIN		BIT(0)
+#define MDIO_MANUALMODE		BIT(31)
+
+#define MDIO_PIN               0
+
 
 	u32	alive;
 	u32	link;
@@ -59,7 +71,9 @@  struct davinci_mdio_regs {
 	u32	userintmasked;
 	u32	userintmaskset;
 	u32	userintmaskclr;
-	u32	__reserved_1[20];
+	u32	manualif;
+	u32	poll;
+	u32	__reserved_1[18];
 
 	struct {
 		u32	access;
@@ -79,6 +93,7 @@  static const struct mdio_platform_data default_pdata = {
 
 struct davinci_mdio_data {
 	struct mdio_platform_data pdata;
+	struct mdiobb_ctrl bb_ctrl;
 	struct davinci_mdio_regs __iomem *regs;
 	struct clk	*clk;
 	struct device	*dev;
@@ -90,6 +105,7 @@  struct davinci_mdio_data {
 	 */
 	bool		skip_scan;
 	u32		clk_div;
+	bool		manual_mode;
 };
 
 static void davinci_mdio_init_clk(struct davinci_mdio_data *data)
@@ -128,9 +144,122 @@  static void davinci_mdio_enable(struct davinci_mdio_data *data)
 	writel(data->clk_div | CONTROL_ENABLE, &data->regs->control);
 }
 
-static int davinci_mdio_reset(struct mii_bus *bus)
+static void davinci_mdio_disable(struct davinci_mdio_data *data)
+{
+	u32 reg;
+
+	/* Disable MDIO state machine */
+	reg = readl(&data->regs->control);
+
+	reg &= ~CONTROL_CLKDIV;
+	reg |= data->clk_div;
+
+	reg &= ~CONTROL_ENABLE;
+	writel(reg, &data->regs->control);
+}
+
+static void davinci_mdio_enable_manual_mode(struct davinci_mdio_data *data)
+{
+	u32 reg;
+	/* set manual mode */
+	reg = readl(&data->regs->poll);
+	reg |= MDIO_MANUALMODE;
+	writel(reg, &data->regs->poll);
+}
+
+static void davinci_set_mdc(struct mdiobb_ctrl *ctrl, int level)
+{
+	struct davinci_mdio_data *data;
+	u32 reg;
+
+	data = container_of(ctrl, struct davinci_mdio_data, bb_ctrl);
+	reg = readl(&data->regs->manualif);
+
+	if (level)
+		reg |= MDIO_MAN_MDCLK_O;
+	else
+		reg &= ~MDIO_MAN_MDCLK_O;
+
+	writel(reg, &data->regs->manualif);
+}
+
+static void davinci_set_mdio_dir(struct mdiobb_ctrl *ctrl, int output)
+{
+	struct davinci_mdio_data *data;
+	u32 reg;
+
+	data = container_of(ctrl, struct davinci_mdio_data, bb_ctrl);
+	reg = readl(&data->regs->manualif);
+
+	if (output)
+		reg |= MDIO_MAN_OE;
+	else
+		reg &= ~MDIO_MAN_OE;
+
+	writel(reg, &data->regs->manualif);
+}
+
+static void  davinci_set_mdio_data(struct mdiobb_ctrl *ctrl, int value)
+{
+	struct davinci_mdio_data *data;
+	u32 reg;
+
+	data = container_of(ctrl, struct davinci_mdio_data, bb_ctrl);
+	reg = readl(&data->regs->manualif);
+
+	if (value)
+		reg |= MDIO_MAN_PIN;
+	else
+		reg &= ~MDIO_MAN_PIN;
+
+	writel(reg, &data->regs->manualif);
+}
+
+static int davinci_get_mdio_data(struct mdiobb_ctrl *ctrl)
+{
+	struct davinci_mdio_data *data;
+	unsigned long reg;
+
+	data = container_of(ctrl, struct davinci_mdio_data, bb_ctrl);
+	reg = readl(&data->regs->manualif);
+	return test_bit(MDIO_PIN, &reg);
+}
+
+static int davinci_mdiobb_read(struct mii_bus *bus, int phy, int reg)
+{
+	int ret;
+
+	ret = pm_runtime_resume_and_get(bus->parent);
+	if (ret < 0)
+		return ret;
+
+	ret = mdiobb_read(bus, phy, reg);
+
+	pm_runtime_mark_last_busy(bus->parent);
+	pm_runtime_put_autosuspend(bus->parent);
+
+	return ret;
+}
+
+static int davinci_mdiobb_write(struct mii_bus *bus, int phy, int reg,
+				u16 val)
+{
+	int ret;
+
+	ret = pm_runtime_resume_and_get(bus->parent);
+	if (ret < 0)
+		return ret;
+
+	ret = mdiobb_write(bus, phy, reg, val);
+
+	pm_runtime_mark_last_busy(bus->parent);
+	pm_runtime_put_autosuspend(bus->parent);
+
+	return ret;
+}
+
+static int davinci_mdio_common_reset(struct davinci_mdio_data *data)
 {
-	struct davinci_mdio_data *data = bus->priv;
 	u32 phy_mask, ver;
 	int ret;
 
@@ -138,6 +267,11 @@  static int davinci_mdio_reset(struct mii_bus *bus)
 	if (ret < 0)
 		return ret;
 
+	if (data->manual_mode) {
+		davinci_mdio_disable(data);
+		davinci_mdio_enable_manual_mode(data);
+	}
+
 	/* wait for scan logic to settle */
 	msleep(PHY_MAX_ADDR * data->access_time);
 
@@ -171,6 +305,23 @@  static int davinci_mdio_reset(struct mii_bus *bus)
 	return 0;
 }
 
+static int davinci_mdio_reset(struct mii_bus *bus)
+{
+	struct davinci_mdio_data *data = bus->priv;
+
+	return davinci_mdio_common_reset(data);
+}
+
+static int davinci_mdiobb_reset(struct mii_bus *bus)
+{
+	struct mdiobb_ctrl *ctrl = bus->priv;
+	struct davinci_mdio_data *data;
+
+	data = container_of(ctrl, struct davinci_mdio_data, bb_ctrl);
+
+	return davinci_mdio_common_reset(data);
+}
+
 /* wait until hardware is ready for another user access */
 static inline int wait_for_user_access(struct davinci_mdio_data *data)
 {
@@ -318,6 +469,28 @@  static int davinci_mdio_probe_dt(struct mdio_platform_data *data,
 	return 0;
 }
 
+struct k3_mdio_soc_data {
+	bool manual_mode;
+};
+
+static const struct k3_mdio_soc_data am65_mdio_soc_data = {
+	.manual_mode = true,
+};
+
+static const struct soc_device_attribute k3_mdio_socinfo[] = {
+	{ .family = "AM62X", .revision = "SR1.0", .data = &am65_mdio_soc_data },
+	{ .family = "AM64X", .revision = "SR1.0", .data = &am65_mdio_soc_data },
+	{ .family = "AM64X", .revision = "SR2.0", .data = &am65_mdio_soc_data },
+	{ .family = "AM65X", .revision = "SR1.0", .data = &am65_mdio_soc_data },
+	{ .family = "AM65X", .revision = "SR2.0", .data = &am65_mdio_soc_data },
+	{ .family = "J7200", .revision = "SR1.0", .data = &am65_mdio_soc_data },
+	{ .family = "J7200", .revision = "SR2.0", .data = &am65_mdio_soc_data },
+	{ .family = "J721E", .revision = "SR1.0", .data = &am65_mdio_soc_data },
+	{ .family = "J721E", .revision = "SR2.0", .data = &am65_mdio_soc_data },
+	{ .family = "J721S2", .revision = "SR1.0", .data = &am65_mdio_soc_data},
+	{ /* sentinel */ },
+};
+
 #if IS_ENABLED(CONFIG_OF)
 static const struct davinci_mdio_of_param of_cpsw_mdio_data = {
 	.autosuspend_delay_ms = 100,
@@ -331,6 +504,14 @@  static const struct of_device_id davinci_mdio_of_mtable[] = {
 MODULE_DEVICE_TABLE(of, davinci_mdio_of_mtable);
 #endif
 
+static const struct mdiobb_ops davinci_mdiobb_ops = {
+	.owner = THIS_MODULE,
+	.set_mdc = davinci_set_mdc,
+	.set_mdio_dir = davinci_set_mdio_dir,
+	.set_mdio_data = davinci_set_mdio_data,
+	.get_mdio_data = davinci_get_mdio_data,
+};
+
 static int davinci_mdio_probe(struct platform_device *pdev)
 {
 	struct mdio_platform_data *pdata = dev_get_platdata(&pdev->dev);
@@ -345,7 +526,26 @@  static int davinci_mdio_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
-	data->bus = devm_mdiobus_alloc(dev);
+	data->manual_mode = false;
+	data->bb_ctrl.ops = &davinci_mdiobb_ops;
+
+	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
+		const struct soc_device_attribute *soc_match_data;
+
+		soc_match_data = soc_device_match(k3_mdio_socinfo);
+		if (soc_match_data && soc_match_data->data) {
+			const struct k3_mdio_soc_data *socdata =
+						soc_match_data->data;
+
+			data->manual_mode = socdata->manual_mode;
+		}
+	}
+
+	if (data->manual_mode)
+		data->bus = alloc_mdio_bitbang(&data->bb_ctrl);
+	else
+		data->bus = devm_mdiobus_alloc(dev);
+
 	if (!data->bus) {
 		dev_err(dev, "failed to alloc mii bus\n");
 		return -ENOMEM;
@@ -371,11 +571,20 @@  static int davinci_mdio_probe(struct platform_device *pdev)
 	}
 
 	data->bus->name		= dev_name(dev);
-	data->bus->read		= davinci_mdio_read;
-	data->bus->write	= davinci_mdio_write;
-	data->bus->reset	= davinci_mdio_reset;
+
+	if (data->manual_mode) {
+		data->bus->read		= davinci_mdiobb_read;
+		data->bus->write	= davinci_mdiobb_write;
+		data->bus->reset	= davinci_mdiobb_reset;
+
+		dev_info(dev, "Configuring MDIO in manual mode\n");
+	} else {
+		data->bus->read		= davinci_mdio_read;
+		data->bus->write	= davinci_mdio_write;
+		data->bus->reset	= davinci_mdio_reset;
+		data->bus->priv		= data;
+	}
 	data->bus->parent	= dev;
-	data->bus->priv		= data;
 
 	data->clk = devm_clk_get(dev, "fck");
 	if (IS_ERR(data->clk)) {
@@ -433,9 +642,13 @@  static int davinci_mdio_remove(struct platform_device *pdev)
 {
 	struct davinci_mdio_data *data = platform_get_drvdata(pdev);
 
-	if (data->bus)
+	if (data->bus) {
 		mdiobus_unregister(data->bus);
 
+		if (data->manual_mode)
+			free_mdio_bitbang(data->bus);
+	}
+
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
@@ -452,7 +665,9 @@  static int davinci_mdio_runtime_suspend(struct device *dev)
 	ctrl = readl(&data->regs->control);
 	ctrl &= ~CONTROL_ENABLE;
 	writel(ctrl, &data->regs->control);
-	wait_for_idle(data);
+
+	if (!data->manual_mode)
+		wait_for_idle(data);
 
 	return 0;
 }
@@ -461,7 +676,12 @@  static int davinci_mdio_runtime_resume(struct device *dev)
 {
 	struct davinci_mdio_data *data = dev_get_drvdata(dev);
 
-	davinci_mdio_enable(data);
+	if (data->manual_mode) {
+		davinci_mdio_disable(data);
+		davinci_mdio_enable_manual_mode(data);
+	} else {
+		davinci_mdio_enable(data);
+	}
 	return 0;
 }
 #endif