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path: root/drivers/mmc/host/sdhci-cns3xxx.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-cns3xxx.c')
-rw-r--r--drivers/mmc/host/sdhci-cns3xxx.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-cns3xxx.c b/drivers/mmc/host/sdhci-cns3xxx.c
new file mode 100644
index 000000000..2a29c7a4f
--- /dev/null
+++ b/drivers/mmc/host/sdhci-cns3xxx.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SDHCI support for CNS3xxx SoC
+ *
+ * Copyright 2008 Cavium Networks
+ * Copyright 2010 MontaVista Software, LLC.
+ *
+ * Authors: Scott Shu
+ * Anton Vorontsov <avorontsov@mvista.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mmc/host.h>
+#include <linux/module.h>
+#include "sdhci-pltfm.h"
+
+static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host)
+{
+ return 150000000;
+}
+
+static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ int div = 1;
+ u16 clk;
+ unsigned long timeout;
+
+ host->mmc->actual_clock = 0;
+
+ sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+
+ if (clock == 0)
+ return;
+
+ while (host->max_clk / div > clock) {
+ /*
+ * On CNS3xxx divider grows linearly up to 4, and then
+ * exponentially up to 256.
+ */
+ if (div < 4)
+ div += 1;
+ else if (div < 256)
+ div *= 2;
+ else
+ break;
+ }
+
+ dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
+ clock, host->max_clk / div);
+
+ /* Divide by 3 is special. */
+ if (div != 3)
+ div >>= 1;
+
+ clk = div << SDHCI_DIVIDER_SHIFT;
+ clk |= SDHCI_CLOCK_INT_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ timeout = 20;
+ while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
+ & SDHCI_CLOCK_INT_STABLE)) {
+ if (timeout == 0) {
+ dev_warn(dev, "clock is unstable");
+ break;
+ }
+ timeout--;
+ mdelay(1);
+ }
+
+ clk |= SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+}
+
+static const struct sdhci_ops sdhci_cns3xxx_ops = {
+ .get_max_clock = sdhci_cns3xxx_get_max_clk,
+ .set_clock = sdhci_cns3xxx_set_clock,
+ .set_bus_width = sdhci_set_bus_width,
+ .reset = sdhci_reset,
+ .set_uhs_signaling = sdhci_set_uhs_signaling,
+};
+
+static const struct sdhci_pltfm_data sdhci_cns3xxx_pdata = {
+ .ops = &sdhci_cns3xxx_ops,
+ .quirks = SDHCI_QUIRK_BROKEN_DMA |
+ SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
+ SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+ SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
+ SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
+};
+
+static int sdhci_cns3xxx_probe(struct platform_device *pdev)
+{
+ return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata, 0);
+}
+
+static struct platform_driver sdhci_cns3xxx_driver = {
+ .driver = {
+ .name = "sdhci-cns3xxx",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ .pm = &sdhci_pltfm_pmops,
+ },
+ .probe = sdhci_cns3xxx_probe,
+ .remove = sdhci_pltfm_unregister,
+};
+
+module_platform_driver(sdhci_cns3xxx_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for CNS3xxx");
+MODULE_AUTHOR("Scott Shu, "
+ "Anton Vorontsov <avorontsov@mvista.com>");
+MODULE_LICENSE("GPL v2");