--- /dev/null
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * iProc SDHCI platform driver
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/mmc/host.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include "sdhci-pltfm.h"
+
+struct sdhci_iproc_data {
+ const struct sdhci_pltfm_data *pdata;
+ u32 caps;
+ u32 caps1;
+};
+
+struct sdhci_iproc_host {
+ const struct sdhci_iproc_data *data;
+ u32 shadow_cmd;
+ u32 shadow_blk;
+};
+
+#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18)
+
+static inline u32 sdhci_iproc_readl(struct sdhci_host *host, int reg)
+{
+ u32 val = readl(host->ioaddr + reg);
+
+ pr_debug("%s: readl [0x%02x] 0x%08x\n",
+ mmc_hostname(host->mmc), reg, val);
+ return val;
+}
+
+static u16 sdhci_iproc_readw(struct sdhci_host *host, int reg)
+{
+ u32 val = sdhci_iproc_readl(host, (reg & ~3));
+ u16 word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff;
+ return word;
+}
+
+static u8 sdhci_iproc_readb(struct sdhci_host *host, int reg)
+{
+ u32 val = sdhci_iproc_readl(host, (reg & ~3));
+ u8 byte = val >> REG_OFFSET_IN_BITS(reg) & 0xff;
+ return byte;
+}
+
+static inline void sdhci_iproc_writel(struct sdhci_host *host, u32 val, int reg)
+{
+ pr_debug("%s: writel [0x%02x] 0x%08x\n",
+ mmc_hostname(host->mmc), reg, val);
+
+ writel(val, host->ioaddr + reg);
+
+ if (host->clock <= 400000) {
+ /* Round up to micro-second four SD clock delay */
+ if (host->clock)
+ udelay((4 * 1000000 + host->clock - 1) / host->clock);
+ else
+ udelay(10);
+ }
+}
+
+/*
+ * The Arasan has a bugette whereby it may lose the content of successive
+ * writes to the same register that are within two SD-card clock cycles of
+ * each other (a clock domain crossing problem). The data
+ * register does not have this problem, which is just as well - otherwise we'd
+ * have to nobble the DMA engine too.
+ *
+ * This wouldn't be a problem with the code except that we can only write the
+ * controller with 32-bit writes. So two different 16-bit registers are
+ * written back to back creates the problem.
+ *
+ * In reality, this only happens when SDHCI_BLOCK_SIZE and SDHCI_BLOCK_COUNT
+ * are written followed by SDHCI_TRANSFER_MODE and SDHCI_COMMAND.
+ * The BLOCK_SIZE and BLOCK_COUNT are meaningless until a command issued so
+ * the work around can be further optimized. We can keep shadow values of
+ * BLOCK_SIZE, BLOCK_COUNT, and TRANSFER_MODE until a COMMAND is issued.
+ * Then, write the BLOCK_SIZE+BLOCK_COUNT in a single 32-bit write followed
+ * by the TRANSFER+COMMAND in another 32-bit write.
+ */
+static void sdhci_iproc_writew(struct sdhci_host *host, u16 val, int reg)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_iproc_host *iproc_host = pltfm_host->priv;
+ u32 word_shift = REG_OFFSET_IN_BITS(reg);
+ u32 mask = 0xffff << word_shift;
+ u32 oldval, newval;
+
+ if (reg == SDHCI_COMMAND) {
+ /* Write the block now as we are issuing a command */
+ if (iproc_host->shadow_blk != 0) {
+ sdhci_iproc_writel(host, iproc_host->shadow_blk,
+ SDHCI_BLOCK_SIZE);
+ iproc_host->shadow_blk = 0;
+ }
+ oldval = iproc_host->shadow_cmd;
+ } else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
+ /* Block size and count are stored in shadow reg */
+ oldval = iproc_host->shadow_blk;
+ } else {
+ /* Read reg, all other registers are not shadowed */
+ oldval = sdhci_iproc_readl(host, (reg & ~3));
+ }
+ newval = (oldval & ~mask) | (val << word_shift);
+
+ if (reg == SDHCI_TRANSFER_MODE) {
+ /* Save the transfer mode until the command is issued */
+ iproc_host->shadow_cmd = newval;
+ } else if (reg == SDHCI_BLOCK_SIZE || reg == SDHCI_BLOCK_COUNT) {
+ /* Save the block info until the command is issued */
+ iproc_host->shadow_blk = newval;
+ } else {
+ /* Command or other regular 32-bit write */
+ sdhci_iproc_writel(host, newval, reg & ~3);
+ }
+}
+
+static void sdhci_iproc_writeb(struct sdhci_host *host, u8 val, int reg)
+{
+ u32 oldval = sdhci_iproc_readl(host, (reg & ~3));
+ u32 byte_shift = REG_OFFSET_IN_BITS(reg);
+ u32 mask = 0xff << byte_shift;
+ u32 newval = (oldval & ~mask) | (val << byte_shift);
+
+ sdhci_iproc_writel(host, newval, reg & ~3);
+}
+
+static const struct sdhci_ops sdhci_iproc_ops = {
+ .read_l = sdhci_iproc_readl,
+ .read_w = sdhci_iproc_readw,
+ .read_b = sdhci_iproc_readb,
+ .write_l = sdhci_iproc_writel,
+ .write_w = sdhci_iproc_writew,
+ .write_b = sdhci_iproc_writeb,
+ .set_clock = sdhci_set_clock,
+ .get_max_clock = sdhci_pltfm_clk_get_max_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_iproc_pltfm_data = {
+ .quirks = SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK,
+ .quirks2 = SDHCI_QUIRK2_ACMD23_BROKEN,
+ .ops = &sdhci_iproc_ops,
+};
+
+static const struct sdhci_iproc_data iproc_data = {
+ .pdata = &sdhci_iproc_pltfm_data,
+ .caps = 0x05E90000,
+ .caps1 = 0x00000064,
+};
+
+static const struct of_device_id sdhci_iproc_of_match[] = {
+ { .compatible = "brcm,sdhci-iproc-cygnus", .data = &iproc_data },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sdhci_iproc_of_match);
+
+static int sdhci_iproc_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ const struct sdhci_iproc_data *iproc_data;
+ struct sdhci_host *host;
+ struct sdhci_iproc_host *iproc_host;
+ struct sdhci_pltfm_host *pltfm_host;
+ int ret;
+
+ match = of_match_device(sdhci_iproc_of_match, &pdev->dev);
+ if (!match)
+ return -EINVAL;
+ iproc_data = match->data;
+
+ host = sdhci_pltfm_init(pdev, iproc_data->pdata, sizeof(*iproc_host));
+ if (IS_ERR(host))
+ return PTR_ERR(host);
+
+ pltfm_host = sdhci_priv(host);
+ iproc_host = sdhci_pltfm_priv(pltfm_host);
+
+ iproc_host->data = iproc_data;
+
+ mmc_of_parse(host->mmc);
+ sdhci_get_of_property(pdev);
+
+ /* Enable EMMC 1/8V DDR capable */
+ host->mmc->caps |= MMC_CAP_1_8V_DDR;
+
+ pltfm_host->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pltfm_host->clk)) {
+ ret = PTR_ERR(pltfm_host->clk);
+ goto err;
+ }
+
+ if (iproc_host->data->pdata->quirks & SDHCI_QUIRK_MISSING_CAPS) {
+ host->caps = iproc_host->data->caps;
+ host->caps1 = iproc_host->data->caps1;
+ }
+
+ return sdhci_add_host(host);
+
+err:
+ sdhci_pltfm_free(pdev);
+ return ret;
+}
+
+static int sdhci_iproc_remove(struct platform_device *pdev)
+{
+ return sdhci_pltfm_unregister(pdev);
+}
+
+static struct platform_driver sdhci_iproc_driver = {
+ .driver = {
+ .name = "sdhci-iproc",
+ .of_match_table = sdhci_iproc_of_match,
+ .pm = SDHCI_PLTFM_PMOPS,
+ },
+ .probe = sdhci_iproc_probe,
+ .remove = sdhci_iproc_remove,
+};
+module_platform_driver(sdhci_iproc_driver);
+
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("IPROC SDHCI driver");
+MODULE_LICENSE("GPL v2");
git.samba.org / sfrench / cifs-2.6.git / commitdiff