[PATCH v10 2/2] memory: mtk-smi: mt8188: Add SMI reset and clamp for MT8188

[Friday Yang <friday.yang@mediatek.com>]

To prevent handling glitch signals during MTCMOS on/off transitions,
SMI requires clamp and reset operations. Parse the reset settings for
SMI LARBs and the clamp settings for the SMI Sub-Common. Register
genpd callback for the SMI LARBs located in image, camera and IPE
subsystems, and apply reset and clamp operations within the callback.

Signed-off-by: Friday Yang <friday.yang@mediatek.com>
---
 drivers/memory/mtk-smi.c | 129 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)

diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
index 733e22f695ab..acc8904dd117 100644
--- a/drivers/memory/mtk-smi.c
+++ b/drivers/memory/mtk-smi.c
@@ -10,11 +10,15 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
 #include <linux/soc/mediatek/mtk_sip_svc.h>
 #include <soc/mediatek/smi.h>
 #include <dt-bindings/memory/mt2701-larb-port.h>
@@ -34,6 +38,8 @@
 #define SMI_FIFO_TH1			0x238
 #define SMI_FIFO_TH2			0x23c
 #define SMI_DCM				0x300
+#define SMI_COMMON_CLAMP_EN_SET		0x3c4
+#define SMI_COMMON_CLAMP_EN_CLR		0x3c8
 #define SMI_DUMMY			0x444
 
 /* SMI LARB */
@@ -134,6 +140,7 @@ struct mtk_smi_larb_gen {
 	unsigned int			larb_direct_to_common_mask;
 	unsigned int			flags_general;
 	const u8			(*ostd)[SMI_LARB_PORT_NR_MAX];
+	const u8			*clamp_port;
 };
 
 struct mtk_smi {
@@ -150,6 +157,7 @@ struct mtk_smi {
 };
 
 struct mtk_smi_larb { /* larb: local arbiter */
+	struct device			*dev;
 	struct mtk_smi			smi;
 	void __iomem			*base;
 	struct device			*smi_common_dev; /* common or sub-common dev */
@@ -157,6 +165,10 @@ struct mtk_smi_larb { /* larb: local arbiter */
 	int				larbid;
 	u32				*mmu;
 	unsigned char			*bank;
+	struct regmap			*smi_comm_syscon; /* smi-comm or sub-comm */
+	u8				smi_comm_in_port_id; /* smi-comm or sub-comm */
+	struct notifier_block		nb;
+	struct reset_control		*rst_con;
 };
 
 static int
@@ -478,6 +490,19 @@ static const u8 mtk_smi_larb_mt8195_ostd[][SMI_LARB_PORT_NR_MAX] = {
 	[28] = {0x1a, 0x0e, 0x0a, 0x0a, 0x0c, 0x0e, 0x10,},
 };
 
+static const u8 mtk_smi_larb_clamp_port_mt8188[MTK_LARB_NR_MAX] = {
+	[9]	= BIT(1), /* larb10 */
+	[10]	= BIT(2), /* larb11a */
+	[11]	= BIT(2), /* larb11b */
+	[12]	= BIT(3), /* larb11c */
+	[13]	= BIT(0), /* larb12 */
+	[16]	= BIT(1), /* larb15 */
+	[17]	= BIT(2), /* larb16a */
+	[18]	= BIT(2), /* larb16b */
+	[19]	= BIT(3), /* larb17a */
+	[20]	= BIT(3), /* larb17b */
+};
+
 static const struct mtk_smi_larb_gen mtk_smi_larb_mt2701 = {
 	.port_in_larb = {
 		LARB0_PORT_OFFSET, LARB1_PORT_OFFSET,
@@ -531,6 +556,7 @@ static const struct mtk_smi_larb_gen mtk_smi_larb_mt8188 = {
 	.flags_general	            = MTK_SMI_FLAG_THRT_UPDATE | MTK_SMI_FLAG_SW_FLAG |
 				      MTK_SMI_FLAG_SLEEP_CTL | MTK_SMI_FLAG_CFG_PORT_SEC_CTL,
 	.ostd		            = mtk_smi_larb_mt8188_ostd,
+	.clamp_port                 = mtk_smi_larb_clamp_port_mt8188,
 };
 
 static const struct mtk_smi_larb_gen mtk_smi_larb_mt8192 = {
@@ -582,6 +608,45 @@ static void mtk_smi_larb_sleep_ctrl_disable(struct mtk_smi_larb *larb)
 	writel_relaxed(0, larb->base + SMI_LARB_SLP_CON);
 }
 
+static int mtk_smi_larb_clamp_protect_enable(struct device *dev, bool enable)
+{
+	struct mtk_smi_larb *larb = dev_get_drvdata(dev);
+	u32 reg;
+	int ret;
+
+	/* smi_comm_syscon may be NULL if the subsys doesn't have bus glitch issues */
+	if (!larb->smi_comm_syscon)
+		return -EINVAL;
+
+	reg = enable ? SMI_COMMON_CLAMP_EN_SET : SMI_COMMON_CLAMP_EN_CLR;
+
+	ret = regmap_write(larb->smi_comm_syscon, reg, larb->smi_comm_in_port_id);
+	if (ret)
+		dev_err(dev, "Unable to %s clamp for input port %d: %d\n",
+			enable ? "enable" : "disable",
+			larb->smi_comm_in_port_id, ret);
+
+	return ret;
+}
+
+static int mtk_smi_genpd_callback(struct notifier_block *nb,
+				  unsigned long flags, void *data)
+{
+	struct mtk_smi_larb *larb = container_of(nb, struct mtk_smi_larb, nb);
+	struct device *dev = larb->dev;
+
+	if (flags == GENPD_NOTIFY_PRE_ON || flags == GENPD_NOTIFY_PRE_OFF) {
+		/* disable related SMI sub-common port */
+		mtk_smi_larb_clamp_protect_enable(dev, true);
+	} else if (flags == GENPD_NOTIFY_ON) {
+		/* enable related SMI sub-common port */
+		reset_control_reset(larb->rst_con);
+		mtk_smi_larb_clamp_protect_enable(dev, false);
+	}
+
+	return NOTIFY_OK;
+}
+
 static int mtk_smi_device_link_common(struct device *dev, struct device **com_dev)
 {
 	struct platform_device *smi_com_pdev;
@@ -638,6 +703,51 @@ static int mtk_smi_dts_clk_init(struct device *dev, struct mtk_smi *smi,
 	return ret;
 }
 
+static int mtk_smi_larb_parse_clamp_optional(struct mtk_smi_larb *larb)
+{
+	struct device *dev = larb->dev;
+	const struct mtk_smi_larb_gen *larb_gen = larb->larb_gen;
+	u32 larb_id;
+	int ret;
+
+	/*
+	 * Only SMI LARBs in camera, image and IPE subsys need to
+	 * apply clamp and reset operations, others can be skipped.
+	 */
+	ret = of_property_read_u32(dev->of_node, "mediatek,larb-id", &larb_id);
+	if (ret || !larb_gen->clamp_port || !larb_gen->clamp_port[larb_id])
+		return 0;
+
+	larb->smi_comm_in_port_id = larb_gen->clamp_port[larb_id];
+	larb->smi_comm_syscon = syscon_regmap_lookup_by_phandle(dev->of_node,
+								"mediatek,smi");
+	if (IS_ERR(larb->smi_comm_syscon)) {
+		larb->smi_comm_syscon = NULL;
+		return dev_err_probe(dev, -EINVAL,
+				     "Unknown clamp port for larb %d\n", larb_id);
+	}
+
+	return 0;
+}
+
+static int mtk_smi_larb_parse_reset_optional(struct mtk_smi_larb *larb)
+{
+	struct device *dev = larb->dev;
+	int ret;
+
+	larb->rst_con = devm_reset_control_get_optional_exclusive(dev, "larb");
+	if (!larb->rst_con)
+		return 0;
+
+	larb->nb.notifier_call = mtk_smi_genpd_callback;
+	ret = dev_pm_genpd_add_notifier(dev, &larb->nb);
+	if (ret)
+		return dev_err_probe(dev, -EINVAL,
+				     "Failed to add genpd callback %d\n", ret);
+
+	return 0;
+}
+
 static int mtk_smi_larb_probe(struct platform_device *pdev)
 {
 	struct mtk_smi_larb *larb;
@@ -648,6 +758,7 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
 	if (!larb)
 		return -ENOMEM;
 
+	larb->dev = dev;
 	larb->larb_gen = of_device_get_match_data(dev);
 	larb->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(larb->base))
@@ -664,6 +775,14 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
+	ret = mtk_smi_larb_parse_clamp_optional(larb);
+	if (ret)
+		goto err_link_remove;
+
+	ret = mtk_smi_larb_parse_reset_optional(larb);
+	if (ret)
+		goto err_link_remove;
+
 	pm_runtime_enable(dev);
 	platform_set_drvdata(pdev, larb);
 	ret = component_add(dev, &mtk_smi_larb_component_ops);
@@ -673,6 +792,7 @@ static int mtk_smi_larb_probe(struct platform_device *pdev)
 
 err_pm_disable:
 	pm_runtime_disable(dev);
+err_link_remove:
 	device_link_remove(dev, larb->smi_common_dev);
 	return ret;
 }
@@ -681,6 +801,9 @@ static void mtk_smi_larb_remove(struct platform_device *pdev)
 {
 	struct mtk_smi_larb *larb = platform_get_drvdata(pdev);
 
+	if (larb->nb.notifier_call)
+		dev_pm_genpd_remove_notifier(&pdev->dev);
+
 	device_link_remove(&pdev->dev, larb->smi_common_dev);
 	pm_runtime_disable(&pdev->dev);
 	component_del(&pdev->dev, &mtk_smi_larb_component_ops);
@@ -803,6 +926,11 @@ static const struct mtk_smi_common_plat mtk_smi_common_mt8188_vpp = {
 	.init     = mtk_smi_common_mt8195_init,
 };
 
+static const struct mtk_smi_common_plat mtk_smi_sub_common_mt8188 = {
+	.type     = MTK_SMI_GEN2_SUB_COMM,
+	.has_gals = true,
+};
+
 static const struct mtk_smi_common_plat mtk_smi_common_mt8192 = {
 	.type     = MTK_SMI_GEN2,
 	.has_gals = true,
@@ -847,6 +975,7 @@ static const struct of_device_id mtk_smi_common_of_ids[] = {
 	{.compatible = "mediatek,mt8186-smi-common", .data = &mtk_smi_common_mt8186},
 	{.compatible = "mediatek,mt8188-smi-common-vdo", .data = &mtk_smi_common_mt8188_vdo},
 	{.compatible = "mediatek,mt8188-smi-common-vpp", .data = &mtk_smi_common_mt8188_vpp},
+	{.compatible = "mediatek,mt8188-smi-sub-common", .data = &mtk_smi_sub_common_mt8188},
 	{.compatible = "mediatek,mt8192-smi-common", .data = &mtk_smi_common_mt8192},
 	{.compatible = "mediatek,mt8195-smi-common-vdo", .data = &mtk_smi_common_mt8195_vdo},
 	{.compatible = "mediatek,mt8195-smi-common-vpp", .data = &mtk_smi_common_mt8195_vpp},
-- 
2.46.0