Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 233 insertions, 0 deletions

diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
new file mode 100644
index 000000000..b8effe77d
--- /dev/null
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 2011 Peter Korsgaard <jacmet@sunsite.dk>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/hw_random.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#define TRNG_CR		0x00
+#define TRNG_MR		0x04
+#define TRNG_ISR	0x1c
+#define TRNG_ISR_DATRDY	BIT(0)
+#define TRNG_ODATA	0x50
+
+#define TRNG_KEY	0x524e4700 /* RNG */
+
+#define TRNG_HALFR	BIT(0) /* generate RN every 168 cycles */
+
+struct atmel_trng_data {
+	bool has_half_rate;
+};
+
+struct atmel_trng {
+	struct clk *clk;
+	void __iomem *base;
+	struct hwrng rng;
+	bool has_half_rate;
+};
+
+static bool atmel_trng_wait_ready(struct atmel_trng *trng, bool wait)
+{
+	int ready;
+
+	ready = readl(trng->base + TRNG_ISR) & TRNG_ISR_DATRDY;
+	if (!ready && wait)
+		readl_poll_timeout(trng->base + TRNG_ISR, ready,
+				   ready & TRNG_ISR_DATRDY, 1000, 20000);
+
+	return !!ready;
+}
+
+static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
+			   bool wait)
+{
+	struct atmel_trng *trng = container_of(rng, struct atmel_trng, rng);
+	u32 *data = buf;
+	int ret;
+
+	ret = pm_runtime_get_sync((struct device *)trng->rng.priv);
+	if (ret < 0) {
+		pm_runtime_put_sync((struct device *)trng->rng.priv);
+		return ret;
+	}
+
+	ret = atmel_trng_wait_ready(trng, wait);
+	if (!ret)
+		goto out;
+
+	*data = readl(trng->base + TRNG_ODATA);
+	/*
+	 * ensure data ready is only set again AFTER the next data word is ready
+	 * in case it got set between checking ISR and reading ODATA, so we
+	 * don't risk re-reading the same word
+	 */
+	readl(trng->base + TRNG_ISR);
+	ret = 4;
+
+out:
+	pm_runtime_mark_last_busy((struct device *)trng->rng.priv);
+	pm_runtime_put_sync_autosuspend((struct device *)trng->rng.priv);
+	return ret;
+}
+
+static int atmel_trng_init(struct atmel_trng *trng)
+{
+	unsigned long rate;
+	int ret;
+
+	ret = clk_prepare_enable(trng->clk);
+	if (ret)
+		return ret;
+
+	if (trng->has_half_rate) {
+		rate = clk_get_rate(trng->clk);
+
+		/* if peripheral clk is above 100MHz, set HALFR */
+		if (rate > 100000000)
+			writel(TRNG_HALFR, trng->base + TRNG_MR);
+	}
+
+	writel(TRNG_KEY | 1, trng->base + TRNG_CR);
+
+	return 0;
+}
+
+static void atmel_trng_cleanup(struct atmel_trng *trng)
+{
+	writel(TRNG_KEY, trng->base + TRNG_CR);
+	clk_disable_unprepare(trng->clk);
+}
+
+static int atmel_trng_probe(struct platform_device *pdev)
+{
+	struct atmel_trng *trng;
+	const struct atmel_trng_data *data;
+	int ret;
+
+	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+	if (!trng)
+		return -ENOMEM;
+
+	trng->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(trng->base))
+		return PTR_ERR(trng->base);
+
+	trng->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(trng->clk))
+		return PTR_ERR(trng->clk);
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -ENODEV;
+
+	trng->has_half_rate = data->has_half_rate;
+	trng->rng.name = pdev->name;
+	trng->rng.read = atmel_trng_read;
+	trng->rng.priv = (unsigned long)&pdev->dev;
+	platform_set_drvdata(pdev, trng);
+
+#ifndef CONFIG_PM
+	ret = atmel_trng_init(trng);
+	if (ret)
+		return ret;
+#endif
+
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 100);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = devm_hwrng_register(&pdev->dev, &trng->rng);
+	if (ret) {
+		pm_runtime_disable(&pdev->dev);
+		pm_runtime_set_suspended(&pdev->dev);
+#ifndef CONFIG_PM
+		atmel_trng_cleanup(trng);
+#endif
+	}
+
+	return ret;
+}
+
+static int atmel_trng_remove(struct platform_device *pdev)
+{
+	struct atmel_trng *trng = platform_get_drvdata(pdev);
+
+	atmel_trng_cleanup(trng);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused atmel_trng_runtime_suspend(struct device *dev)
+{
+	struct atmel_trng *trng = dev_get_drvdata(dev);
+
+	atmel_trng_cleanup(trng);
+
+	return 0;
+}
+
+static int __maybe_unused atmel_trng_runtime_resume(struct device *dev)
+{
+	struct atmel_trng *trng = dev_get_drvdata(dev);
+
+	return atmel_trng_init(trng);
+}
+
+static const struct dev_pm_ops __maybe_unused atmel_trng_pm_ops = {
+	SET_RUNTIME_PM_OPS(atmel_trng_runtime_suspend,
+			   atmel_trng_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
+static const struct atmel_trng_data at91sam9g45_config = {
+	.has_half_rate = false,
+};
+
+static const struct atmel_trng_data sam9x60_config = {
+	.has_half_rate = true,
+};
+
+static const struct of_device_id atmel_trng_dt_ids[] = {
+	{
+		.compatible = "atmel,at91sam9g45-trng",
+		.data = &at91sam9g45_config,
+	}, {
+		.compatible = "microchip,sam9x60-trng",
+		.data = &sam9x60_config,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, atmel_trng_dt_ids);
+
+static struct platform_driver atmel_trng_driver = {
+	.probe		= atmel_trng_probe,
+	.remove		= atmel_trng_remove,
+	.driver		= {
+		.name	= "atmel-trng",
+		.pm	= pm_ptr(&atmel_trng_pm_ops),
+		.of_match_table = atmel_trng_dt_ids,
+	},
+};
+
+module_platform_driver(atmel_trng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
+MODULE_DESCRIPTION("Atmel true random number generator driver");