soc: ti: pm33xx: Simplify RTC usage to prepare to drop platform data

We must re-enable the RTC module clock enabled in RTC+DDR suspend, and
pm33xx has been using platform data callbacks for that. Looks like for
retention suspend the RTC module clock must not be re-enabled.

To remove the legacy platform data callbacks, and eventually be able to
drop the RTC legacy platform data, let's manage the RTC module clock
and register range directly in pm33xx.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 42 insertions, 5 deletions

diff --git a/drivers/soc/ti/pm33xx.c b/drivers/soc/ti/pm33xx.c
index de0123ec8ad6..d2f5e7001a93 100644
--- a/drivers/soc/ti/pm33xx.c
+++ b/drivers/soc/ti/pm33xx.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/platform_data/pm33xx.h>
 #include <linux/platform_device.h>
 #include <linux/rtc.h>
@@ -39,6 +40,8 @@
 #define GIC_INT_SET_PENDING_BASE 0x200
 #define AM43XX_GIC_DIST_BASE	0x48241000
 
+static void __iomem *rtc_base_virt;
+static struct clk *rtc_fck;
 static u32 rtc_magic_val;
 
 static int (*am33xx_do_wfi_sram)(unsigned long unused);
@@ -90,7 +93,7 @@ static int am33xx_push_sram_idle(void)
 	ro_sram_data.amx3_pm_sram_data_virt = ocmcram_location_data;
 	ro_sram_data.amx3_pm_sram_data_phys =
 		gen_pool_virt_to_phys(sram_pool_data, ocmcram_location_data);
-	ro_sram_data.rtc_base_virt = pm_ops->get_rtc_base_addr();
+	ro_sram_data.rtc_base_virt = rtc_base_virt;
 
 	/* Save physical address to calculate resume offset during pm init */
 	am33xx_do_wfi_sram_phys = gen_pool_virt_to_phys(sram_pool,
@@ -158,7 +161,7 @@ static struct wkup_m3_wakeup_src rtc_wake_src(void)
 {
 	u32 i;
 
-	i = __raw_readl(pm_ops->get_rtc_base_addr() + 0x44) & 0x40;
+	i = __raw_readl(rtc_base_virt + 0x44) & 0x40;
 
 	if (i) {
 		retrigger_irq = rtc_alarm_wakeup.irq_nr;
@@ -177,13 +180,24 @@ static int am33xx_rtc_only_idle(unsigned long wfi_flags)
 	return 0;
 }
 
+/*
+ * Note that the RTC module clock must be re-enabled only for rtc+ddr suspend.
+ * And looks like the module can stay in SYSC_IDLE_SMART_WKUP mode configured
+ * by the interconnect code just fine for both rtc+ddr suspend and retention
+ * suspend.
+ */
 static int am33xx_pm_suspend(suspend_state_t suspend_state)
 {
 	int i, ret = 0;
 
 	if (suspend_state == PM_SUSPEND_MEM &&
 	    pm_ops->check_off_mode_enable()) {
-		pm_ops->prepare_rtc_suspend();
+		ret = clk_prepare_enable(rtc_fck);
+		if (ret) {
+			dev_err(pm33xx_dev, "Failed to enable clock: %i\n", ret);
+			return ret;
+		}
+
 		pm_ops->save_context();
 		suspend_wfi_flags |= WFI_FLAG_RTC_ONLY;
 		clk_save_context();
@@ -236,7 +250,7 @@ static int am33xx_pm_suspend(suspend_state_t suspend_state)
 	}
 
 	if (suspend_state == PM_SUSPEND_MEM && pm_ops->check_off_mode_enable())
-		pm_ops->prepare_rtc_resume();
+		clk_disable_unprepare(rtc_fck);
 
 	return ret;
 }
@@ -425,14 +439,28 @@ static int am33xx_pm_rtc_setup(void)
 	struct device_node *np;
 	unsigned long val = 0;
 	struct nvmem_device *nvmem;
+	int error;
 
 	np = of_find_node_by_name(NULL, "rtc");
 
 	if (of_device_is_available(np)) {
+		/* RTC interconnect target module clock */
+		rtc_fck = of_clk_get_by_name(np->parent, "fck");
+		if (IS_ERR(rtc_fck))
+			return PTR_ERR(rtc_fck);
+
+		rtc_base_virt = of_iomap(np, 0);
+		if (!rtc_base_virt) {
+			pr_warn("PM: could not iomap rtc");
+			error = -ENODEV;
+			goto err_clk_put;
+		}
+
 		omap_rtc = rtc_class_open("rtc0");
 		if (!omap_rtc) {
 			pr_warn("PM: rtc0 not available");
-			return -EPROBE_DEFER;
+			error = -EPROBE_DEFER;
+			goto err_iounmap;
 		}
 
 		nvmem = devm_nvmem_device_get(&omap_rtc->dev,
@@ -454,6 +482,13 @@ static int am33xx_pm_rtc_setup(void)
 	}
 
 	return 0;
+
+err_iounmap:
+	iounmap(rtc_base_virt);
+err_clk_put:
+	clk_put(rtc_fck);
+
+	return error;
 }
 
 static int am33xx_pm_probe(struct platform_device *pdev)
@@ -544,6 +579,8 @@ static int am33xx_pm_remove(struct platform_device *pdev)
 	suspend_set_ops(NULL);
 	wkup_m3_ipc_put(m3_ipc);
 	am33xx_pm_free_sram();
+	iounmap(rtc_base_virt);
+	clk_put(rtc_fck);
 	return 0;
 }