drivers: Defer probe if firmware is not ready

Driver needs ZynqMP firmware interface to call EEMI
APIs. In case firmware is not ready, dependent drivers
should wait until the firmware is ready.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

10 files changed, 47 insertions, 28 deletions

diff --git a/Documentation/xilinx/eemi.txt b/Documentation/xilinx/eemi.txt
index 0ab686c173be..5f39b4ffdcd4 100644
--- a/Documentation/xilinx/eemi.txt
+++ b/Documentation/xilinx/eemi.txt
@@ -41,8 +41,8 @@ Example of EEMI ops usage:
 	int ret;
 
 	eemi_ops = zynqmp_pm_get_eemi_ops();
-	if (!eemi_ops)
-		return -ENXIO;
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
 
 	ret = eemi_ops->query_data(qdata, ret_payload);
 
diff --git a/drivers/clk/zynqmp/clkc.c b/drivers/clk/zynqmp/clkc.c
index b0908ec62f73..2b1d43457f09 100644
--- a/drivers/clk/zynqmp/clkc.c
+++ b/drivers/clk/zynqmp/clkc.c
@@ -695,8 +695,8 @@ static int zynqmp_clock_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 
 	eemi_ops = zynqmp_pm_get_eemi_ops();
-	if (!eemi_ops)
-		return -ENXIO;
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
 
 	ret = zynqmp_clk_setup(dev->of_node);
 
diff --git a/drivers/firmware/xilinx/zynqmp-debug.c b/drivers/firmware/xilinx/zynqmp-debug.c
index 90b66cdbfd58..c6d0724da4db 100644
--- a/drivers/firmware/xilinx/zynqmp-debug.c
+++ b/drivers/firmware/xilinx/zynqmp-debug.c
@@ -90,9 +90,6 @@ static int process_api_request(u32 pm_id, u64 *pm_api_arg, u32 *pm_api_ret)
 	int ret;
 	struct zynqmp_pm_query_data qdata = {0};
 
-	if (!eemi_ops)
-		return -ENXIO;
-
 	switch (pm_id) {
 	case PM_GET_API_VERSION:
 		ret = eemi_ops->get_api_version(&pm_api_version);
diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index 98f936125643..87a1d636c0dc 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -24,6 +24,8 @@
 #include <linux/firmware/xlnx-zynqmp.h>
 #include "zynqmp-debug.h"
 
+static const struct zynqmp_eemi_ops *eemi_ops_tbl;
+
 static const struct mfd_cell firmware_devs[] = {
 	{
 		.name = "zynqmp_power_controller",
@@ -649,7 +651,11 @@ static const struct zynqmp_eemi_ops eemi_ops = {
  */
 const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void)
 {
-	return &eemi_ops;
+	if (eemi_ops_tbl)
+		return eemi_ops_tbl;
+	else
+		return ERR_PTR(-EPROBE_DEFER);
+
 }
 EXPORT_SYMBOL_GPL(zynqmp_pm_get_eemi_ops);
 
@@ -694,6 +700,9 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
 	pr_info("%s Trustzone version v%d.%d\n", __func__,
 		pm_tz_version >> 16, pm_tz_version & 0xFFFF);
 
+	/* Assign eemi_ops_table */
+	eemi_ops_tbl = &eemi_ops;
+
 	zynqmp_pm_api_debugfs_init();
 
 	ret = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE, firmware_devs,
diff --git a/drivers/nvmem/zynqmp_nvmem.c b/drivers/nvmem/zynqmp_nvmem.c
index 490c8fcaec80..5893543918c8 100644
--- a/drivers/nvmem/zynqmp_nvmem.c
+++ b/drivers/nvmem/zynqmp_nvmem.c
@@ -16,6 +16,8 @@ struct zynqmp_nvmem_data {
 	struct nvmem_device *nvmem;
 };
 
+static const struct zynqmp_eemi_ops *eemi_ops;
+
 static int zynqmp_nvmem_read(void *context, unsigned int offset,
 			     void *val, size_t bytes)
 {
@@ -23,9 +25,7 @@ static int zynqmp_nvmem_read(void *context, unsigned int offset,
 	int idcode, version;
 	struct zynqmp_nvmem_data *priv = context;
 
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
-
-	if (!eemi_ops || !eemi_ops->get_chipid)
+	if (!eemi_ops->get_chipid)
 		return -ENXIO;
 
 	ret = eemi_ops->get_chipid(&idcode, &version);
@@ -61,6 +61,10 @@ static int zynqmp_nvmem_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
+	eemi_ops = zynqmp_pm_get_eemi_ops();
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
+
 	priv->dev = dev;
 	econfig.dev = dev;
 	econfig.reg_read = zynqmp_nvmem_read;
diff --git a/drivers/reset/reset-zynqmp.c b/drivers/reset/reset-zynqmp.c
index 2ef1f13aa47b..99e75d92dada 100644
--- a/drivers/reset/reset-zynqmp.c
+++ b/drivers/reset/reset-zynqmp.c
@@ -79,11 +79,11 @@ static int zynqmp_reset_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, priv);
-
 	priv->eemi_ops = zynqmp_pm_get_eemi_ops();
-	if (!priv->eemi_ops)
-		return -ENXIO;
+	if (IS_ERR(priv->eemi_ops))
+		return PTR_ERR(priv->eemi_ops);
+
+	platform_set_drvdata(pdev, priv);
 
 	priv->rcdev.ops = &zynqmp_reset_ops;
 	priv->rcdev.owner = THIS_MODULE;
diff --git a/drivers/soc/xilinx/zynqmp_pm_domains.c b/drivers/soc/xilinx/zynqmp_pm_domains.c
index 354d256e6e00..600f57cf0c2e 100644
--- a/drivers/soc/xilinx/zynqmp_pm_domains.c
+++ b/drivers/soc/xilinx/zynqmp_pm_domains.c
@@ -23,6 +23,8 @@
 /* Flag stating if PM nodes mapped to the PM domain has been requested */
 #define ZYNQMP_PM_DOMAIN_REQUESTED	BIT(0)
 
+static const struct zynqmp_eemi_ops *eemi_ops;
+
 /**
  * struct zynqmp_pm_domain - Wrapper around struct generic_pm_domain
  * @gpd:		Generic power domain
@@ -71,9 +73,8 @@ static int zynqmp_gpd_power_on(struct generic_pm_domain *domain)
 {
 	int ret;
 	struct zynqmp_pm_domain *pd;
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
 
-	if (!eemi_ops || !eemi_ops->set_requirement)
+	if (!eemi_ops->set_requirement)
 		return -ENXIO;
 
 	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
@@ -107,9 +108,8 @@ static int zynqmp_gpd_power_off(struct generic_pm_domain *domain)
 	struct zynqmp_pm_domain *pd;
 	u32 capabilities = 0;
 	bool may_wakeup;
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
 
-	if (!eemi_ops || !eemi_ops->set_requirement)
+	if (!eemi_ops->set_requirement)
 		return -ENXIO;
 
 	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
@@ -160,9 +160,8 @@ static int zynqmp_gpd_attach_dev(struct generic_pm_domain *domain,
 {
 	int ret;
 	struct zynqmp_pm_domain *pd;
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
 
-	if (!eemi_ops || !eemi_ops->request_node)
+	if (!eemi_ops->request_node)
 		return -ENXIO;
 
 	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
@@ -197,9 +196,8 @@ static void zynqmp_gpd_detach_dev(struct generic_pm_domain *domain,
 {
 	int ret;
 	struct zynqmp_pm_domain *pd;
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
 
-	if (!eemi_ops || !eemi_ops->release_node)
+	if (!eemi_ops->release_node)
 		return;
 
 	pd = container_of(domain, struct zynqmp_pm_domain, gpd);
@@ -266,6 +264,10 @@ static int zynqmp_gpd_probe(struct platform_device *pdev)
 	struct zynqmp_pm_domain *pd;
 	struct device *dev = &pdev->dev;
 
+	eemi_ops = zynqmp_pm_get_eemi_ops();
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
+
 	pd = devm_kcalloc(dev, ZYNQMP_NUM_DOMAINS, sizeof(*pd), GFP_KERNEL);
 	if (!pd)
 		return -ENOMEM;
diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
index 771cb59b9d22..1b9d14411a15 100644
--- a/drivers/soc/xilinx/zynqmp_power.c
+++ b/drivers/soc/xilinx/zynqmp_power.c
@@ -31,6 +31,7 @@ static const char *const suspend_modes[] = {
 };
 
 static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
+static const struct zynqmp_eemi_ops *eemi_ops;
 
 enum pm_api_cb_id {
 	PM_INIT_SUSPEND_CB = 30,
@@ -92,9 +93,8 @@ static ssize_t suspend_mode_store(struct device *dev,
 				  const char *buf, size_t count)
 {
 	int md, ret = -EINVAL;
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
 
-	if (!eemi_ops || !eemi_ops->set_suspend_mode)
+	if (!eemi_ops->set_suspend_mode)
 		return ret;
 
 	for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
@@ -120,9 +120,11 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
 	int ret, irq;
 	u32 pm_api_version;
 
-	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+	eemi_ops = zynqmp_pm_get_eemi_ops();
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
 
-	if (!eemi_ops || !eemi_ops->get_api_version || !eemi_ops->init_finalize)
+	if (!eemi_ops->get_api_version || !eemi_ops->init_finalize)
 		return -ENXIO;
 
 	eemi_ops->init_finalize();
diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 9f83e1b17aa1..d07b6f940f9f 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -138,6 +138,7 @@
 
 #define SPI_AUTOSUSPEND_TIMEOUT		3000
 enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
+static const struct zynqmp_eemi_ops *eemi_ops;
 
 /**
  * struct zynqmp_qspi - Defines qspi driver instance
@@ -1021,6 +1022,10 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct device *dev = &pdev->dev;
 
+	eemi_ops = zynqmp_pm_get_eemi_ops();
+	if (IS_ERR(eemi_ops))
+		return PTR_ERR(eemi_ops);
+
 	master = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
 	if (!master)
 		return -ENOMEM;
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 642dab10f65d..3533ee557043 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -293,7 +293,7 @@ const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void);
 #else
 static inline struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void)
 {
-	return NULL;
+	return ERR_PTR(-ENODEV);
 }
 #endif