[PATCH v3 02/13] mtd: st_spi_fsm: Obtain and use EMI clock

@@ -24,6 +24,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/clk.h>
 
 #include "serial_flash_cmds.h"
 

@@ -262,6 +263,7 @@ struct stfsm {
 	struct mtd_info		mtd;
 	struct mutex		lock;
 	struct flash_info       *info;
+	struct clk              *clk;
 
 	uint32_t                configuration;
 	uint32_t                fifo_dir_delay;

@@ -1906,8 +1908,7 @@ static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq)
 	uint32_t emi_freq;
 	uint32_t clk_div;
 
-	/* TODO: Make this dynamic */
-	emi_freq = STFSM_DEFAULT_EMI_FREQ;
+	emi_freq = clk_get_rate(fsm->clk);
 
 	/*
 	 * Calculate clk_div - values between 2 and 128

@@ -2057,6 +2058,18 @@ static int stfsm_probe(struct platform_device *pdev)
 		return PTR_ERR(fsm->base);
 	}
 
+	fsm->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(fsm->clk)) {
+		dev_err(fsm->dev, "Couldn't find EMI clock.\n");
+		return PTR_ERR(fsm->clk);
+	}
+
+	ret = clk_prepare_enable(fsm->clk);
+	if (ret) {
+		dev_err(fsm->dev, "Failed to enable EMI clock.\n");
+		return ret;
+	}
+
 	mutex_init(&fsm->lock);
 
 	ret = stfsm_init(fsm);

@@ -2121,6 +2134,28 @@ static int stfsm_remove(struct platform_device *pdev)
 	return mtd_device_unregister(&fsm->mtd);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int stfsmfsm_suspend(struct device *dev)
+{
+	struct stfsm *fsm = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(fsm->clk);
+
+	return 0;
+}
+
+static int stfsmfsm_resume(struct device *dev)
+{
+	struct stfsm *fsm = dev_get_drvdata(dev);
+
+	clk_prepare_enable(fsm->clk);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stfsm_pm_ops, stfsmfsm_suspend, stfsmfsm_resume);
+
 static const struct of_device_id stfsm_match[] = {
 	{ .compatible = "st,spi-fsm", },
 	{},

@@ -2134,6 +2169,7 @@ static struct platform_driver stfsm_driver = {
 		.name	= "st-spi-fsm",
 		.owner	= THIS_MODULE,
 		.of_match_table = stfsm_match,
+		.pm     = &stfsm_pm_ops,
 	},
 };
 module_platform_driver(stfsm_driver);