--- /dev/null
+/* linux/drivers/mmc/host/sdhci-s3c.c
+ *
+ * Copyright 2008 Openmoko Inc.
+ * Copyright 2008 Simtec Electronics
+ * Ben Dooks <ben@simtec.co.uk>
+ * http://armlinux.simtec.co.uk/
+ *
+ * SDHCI (HSMMC) support for Samsung SoC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <linux/mmc/host.h>
+
+#include <plat/sdhci.h>
+#include <plat/regs-sdhci.h>
+
+#include "sdhci.h"
+
+#define MAX_BUS_CLK (4)
+
+/**
+ * struct sdhci_s3c - S3C SDHCI instance
+ * @host: The SDHCI host created
+ * @pdev: The platform device we where created from.
+ * @ioarea: The resource created when we claimed the IO area.
+ * @pdata: The platform data for this controller.
+ * @cur_clk: The index of the current bus clock.
+ * @clk_io: The clock for the internal bus interface.
+ * @clk_bus: The clocks that are available for the SD/MMC bus clock.
+ */
+struct sdhci_s3c {
+ struct sdhci_host *host;
+ struct platform_device *pdev;
+ struct resource *ioarea;
+ struct s3c_sdhci_platdata *pdata;
+ unsigned int cur_clk;
+
+ struct clk *clk_io;
+ struct clk *clk_bus[MAX_BUS_CLK];
+};
+
+static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
+{
+ return sdhci_priv(host);
+}
+
+/**
+ * get_curclk - convert ctrl2 register to clock source number
+ * @ctrl2: Control2 register value.
+ */
+static u32 get_curclk(u32 ctrl2)
+{
+ ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+ ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+
+ return ctrl2;
+}
+
+static void sdhci_s3c_check_sclk(struct sdhci_host *host)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+ u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
+
+ if (get_curclk(tmp) != ourhost->cur_clk) {
+ dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
+
+ tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+ tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+ writel(tmp, host->ioaddr + 0x80);
+ }
+}
+
+/**
+ * sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
+ * @host: The SDHCI host instance.
+ *
+ * Callback to return the maximum clock rate acheivable by the controller.
+*/
+static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+ struct clk *busclk;
+ unsigned int rate, max;
+ int clk;
+
+ /* note, a reset will reset the clock source */
+
+ sdhci_s3c_check_sclk(host);
+
+ for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
+ busclk = ourhost->clk_bus[clk];
+ if (!busclk)
+ continue;
+
+ rate = clk_get_rate(busclk);
+ if (rate > max)
+ max = rate;
+ }
+
+ return max;
+}
+
+static unsigned int sdhci_s3c_get_timeout_clk(struct sdhci_host *host)
+{
+ return sdhci_s3c_get_max_clk(host) / 1000000;
+}
+
+/**
+ * sdhci_s3c_consider_clock - consider one the bus clocks for current setting
+ * @ourhost: Our SDHCI instance.
+ * @src: The source clock index.
+ * @wanted: The clock frequency wanted.
+ */
+static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
+ unsigned int src,
+ unsigned int wanted)
+{
+ unsigned long rate;
+ struct clk *clksrc = ourhost->clk_bus[src];
+ int div;
+
+ if (!clksrc)
+ return UINT_MAX;
+
+ rate = clk_get_rate(clksrc);
+
+ for (div = 1; div < 256; div *= 2) {
+ if ((rate / div) <= wanted)
+ break;
+ }
+
+ dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
+ src, rate, wanted, rate / div);
+
+ return (wanted - (rate / div));
+}
+
+/**
+ * sdhci_s3c_set_clock - callback on clock change
+ * @host: The SDHCI host being changed
+ * @clock: The clock rate being requested.
+ *
+ * When the card's clock is going to be changed, look at the new frequency
+ * and find the best clock source to go with it.
+*/
+static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+ unsigned int best = UINT_MAX;
+ unsigned int delta;
+ int best_src = 0;
+ int src;
+ u32 ctrl;
+
+ /* don't bother if the clock is going off. */
+ if (clock == 0)
+ return;
+
+ for (src = 0; src < MAX_BUS_CLK; src++) {
+ delta = sdhci_s3c_consider_clock(ourhost, src, clock);
+ if (delta < best) {
+ best = delta;
+ best_src = src;
+ }
+ }
+
+ dev_dbg(&ourhost->pdev->dev,
+ "selected source %d, clock %d, delta %d\n",
+ best_src, clock, best);
+
+ /* select the new clock source */
+
+ if (ourhost->cur_clk != best_src) {
+ struct clk *clk = ourhost->clk_bus[best_src];
+
+ /* turn clock off to card before changing clock source */
+ writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
+
+ ourhost->cur_clk = best_src;
+ host->max_clk = clk_get_rate(clk);
+ host->timeout_clk = sdhci_s3c_get_timeout_clk(host);
+
+ ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
+ ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+ ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+ writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
+ }
+
+ /* reconfigure the hardware for new clock rate */
+
+ {
+ struct mmc_ios ios;
+
+ ios.clock = clock;
+
+ if (ourhost->pdata->cfg_card)
+ (ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
+ &ios, NULL);
+ }
+}
+
+static struct sdhci_ops sdhci_s3c_ops = {
+ .get_max_clock = sdhci_s3c_get_max_clk,
+ .get_timeout_clock = sdhci_s3c_get_timeout_clk,
+ .set_clock = sdhci_s3c_set_clock,
+};
+
+static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
+{
+ struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
+ struct device *dev = &pdev->dev;
+ struct sdhci_host *host;
+ struct sdhci_s3c *sc;
+ struct resource *res;
+ int ret, irq, ptr, clks;
+
+ if (!pdata) {
+ dev_err(dev, "no device data specified\n");
+ return -ENOENT;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(dev, "no irq specified\n");
+ return irq;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "no memory specified\n");
+ return -ENOENT;
+ }
+
+ host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
+ if (IS_ERR(host)) {
+ dev_err(dev, "sdhci_alloc_host() failed\n");
+ return PTR_ERR(host);
+ }
+
+ sc = sdhci_priv(host);
+
+ sc->host = host;
+ sc->pdev = pdev;
+ sc->pdata = pdata;
+
+ platform_set_drvdata(pdev, host);
+
+ sc->clk_io = clk_get(dev, "hsmmc");
+ if (IS_ERR(sc->clk_io)) {
+ dev_err(dev, "failed to get io clock\n");
+ ret = PTR_ERR(sc->clk_io);
+ goto err_io_clk;
+ }
+
+ /* enable the local io clock and keep it running for the moment. */
+ clk_enable(sc->clk_io);
+
+ for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
+ struct clk *clk;
+ char *name = pdata->clocks[ptr];
+
+ if (name == NULL)
+ continue;
+
+ clk = clk_get(dev, name);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "failed to get clock %s\n", name);
+ continue;
+ }
+
+ clks++;
+ sc->clk_bus[ptr] = clk;
+ clk_enable(clk);
+
+ dev_info(dev, "clock source %d: %s (%ld Hz)\n",
+ ptr, name, clk_get_rate(clk));
+ }
+
+ if (clks == 0) {
+ dev_err(dev, "failed to find any bus clocks\n");
+ ret = -ENOENT;
+ goto err_no_busclks;
+ }
+
+ sc->ioarea = request_mem_region(res->start, resource_size(res),
+ mmc_hostname(host->mmc));
+ if (!sc->ioarea) {
+ dev_err(dev, "failed to reserve register area\n");
+ ret = -ENXIO;
+ goto err_req_regs;
+ }
+
+ host->ioaddr = ioremap_nocache(res->start, resource_size(res));
+ if (!host->ioaddr) {
+ dev_err(dev, "failed to map registers\n");
+ ret = -ENXIO;
+ goto err_req_regs;
+ }
+
+ /* Ensure we have minimal gpio selected CMD/CLK/Detect */
+ if (pdata->cfg_gpio)
+ pdata->cfg_gpio(pdev, pdata->max_width);
+
+ host->hw_name = "samsung-hsmmc";
+ host->ops = &sdhci_s3c_ops;
+ host->quirks = 0;
+ host->irq = irq;
+
+ /* Setup quirks for the controller */
+
+ /* Currently with ADMA enabled we are getting some length
+ * interrupts that are not being dealt with, do disable
+ * ADMA until this is sorted out. */
+ host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
+ host->quirks |= SDHCI_QUIRK_32BIT_ADMA_SIZE;
+
+#ifndef CONFIG_MMC_SDHCI_S3C_DMA
+
+ /* we currently see overruns on errors, so disable the SDMA
+ * support as well. */
+ host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
+
+#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
+
+ /* It seems we do not get an DATA transfer complete on non-busy
+ * transfers, not sure if this is a problem with this specific
+ * SDHCI block, or a missing configuration that needs to be set. */
+ host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
+
+ host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
+ SDHCI_QUIRK_32BIT_DMA_SIZE);
+
+ ret = sdhci_add_host(host);
+ if (ret) {
+ dev_err(dev, "sdhci_add_host() failed\n");
+ goto err_add_host;
+ }
+
+ return 0;
+
+ err_add_host:
+ release_resource(sc->ioarea);
+ kfree(sc->ioarea);
+
+ err_req_regs:
+ for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
+ clk_disable(sc->clk_bus[ptr]);
+ clk_put(sc->clk_bus[ptr]);
+ }
+
+ err_no_busclks:
+ clk_disable(sc->clk_io);
+ clk_put(sc->clk_io);
+
+ err_io_clk:
+ sdhci_free_host(host);
+
+ return ret;
+}
+
+static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
+{
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm)
+{
+ struct sdhci_host *host = platform_get_drvdata(dev);
+
+ sdhci_suspend_host(host, pm);
+ return 0;
+}
+
+static int sdhci_s3c_resume(struct platform_device *dev)
+{
+ struct sdhci_host *host = platform_get_drvdata(dev);
+
+ sdhci_resume_host(host);
+ return 0;
+}
+
+#else
+#define sdhci_s3c_suspend NULL
+#define sdhci_s3c_resume NULL
+#endif
+
+static struct platform_driver sdhci_s3c_driver = {
+ .probe = sdhci_s3c_probe,
+ .remove = __devexit_p(sdhci_s3c_remove),
+ .suspend = sdhci_s3c_suspend,
+ .resume = sdhci_s3c_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "s3c-sdhci",
+ },
+};
+
+static int __init sdhci_s3c_init(void)
+{
+ return platform_driver_register(&sdhci_s3c_driver);
+}
+
+static void __exit sdhci_s3c_exit(void)
+{
+ platform_driver_unregister(&sdhci_s3c_driver);
+}
+
+module_init(sdhci_s3c_init);
+module_exit(sdhci_s3c_exit);
+
+MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:s3c-sdhci");
projects / openwrt / staging / blogic.git / commitdiff