spi: spi-geni-qcom: Use OPP API to set clk/perf state

geni spi needs to express a perforamnce state requirement on CX
depending on the frequency of the clock rates. Use OPP table from
DT to register with OPP framework and use dev_pm_opp_set_rate() to
set the clk/perf state.
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Alok Chauhan <alokc@codeaurora.org>
Cc: Akash Asthana <akashast@codeaurora.org>
Cc: linux-spi@vger.kernel.org
Link: https://lore.kernel.org/r/1592222564-13556-3-git-send-email-rnayak@codeaurora.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/spi/spi-geni-qcom.c

@@ -7,6 +7,7 @@
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
 #include <linux/pm_runtime.h>
 #include <linux/qcom-geni-se.h>
 #include <linux/spi/spi.h>
@@ -95,7 +96,6 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
 {
 	unsigned long sclk_freq;
 	unsigned int actual_hz;
-	struct geni_se *se = &mas->se;
 	int ret;
 
 	ret = geni_se_clk_freq_match(&mas->se,
@@ -112,9 +112,9 @@ static int get_spi_clk_cfg(unsigned int speed_hz,
 
 	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
 				actual_hz, sclk_freq, *clk_idx, *clk_div);
-	ret = clk_set_rate(se->clk, sclk_freq);
+	ret = dev_pm_opp_set_rate(mas->dev, sclk_freq);
 	if (ret)
-		dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
+		dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
 	return ret;
 }
 
@@ -568,6 +568,17 @@ static int spi_geni_probe(struct platform_device *pdev)
 	mas->se.wrapper = dev_get_drvdata(dev->parent);
 	mas->se.base = base;
 	mas->se.clk = clk;
+	mas->se.opp_table = dev_pm_opp_set_clkname(&pdev->dev, "se");
+	if (IS_ERR(mas->se.opp_table))
+		return PTR_ERR(mas->se.opp_table);
+	/* OPP table is optional */
+	ret = dev_pm_opp_of_add_table(&pdev->dev);
+	if (!ret) {
+		mas->se.has_opp_table = true;
+	} else if (ret != -ENODEV) {
+		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
+		return ret;
+	}
 
 	spi->bus_num = -1;
 	spi->dev.of_node = dev->of_node;
@@ -614,6 +625,9 @@ static int spi_geni_probe(struct platform_device *pdev)
 spi_geni_probe_runtime_disable:
 	pm_runtime_disable(dev);
 	spi_master_put(spi);
+	if (mas->se.has_opp_table)
+		dev_pm_opp_of_remove_table(&pdev->dev);
+	dev_pm_opp_put_clkname(mas->se.opp_table);
 	return ret;
 }
 
@@ -627,6 +641,9 @@ static int spi_geni_remove(struct platform_device *pdev)
 
 	free_irq(mas->irq, spi);
 	pm_runtime_disable(&pdev->dev);
+	if (mas->se.has_opp_table)
+		dev_pm_opp_of_remove_table(&pdev->dev);
+	dev_pm_opp_put_clkname(mas->se.opp_table);
 	return 0;
 }
 
@@ -636,6 +653,9 @@ static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
 	struct spi_geni_master *mas = spi_master_get_devdata(spi);
 	int ret;
 
+	/* Drop the performance state vote */
+	dev_pm_opp_set_rate(dev, 0);
+
 	ret = geni_se_resources_off(&mas->se);
 	if (ret)
 		return ret;