--- /dev/null
+/*
+ * Support of SDHCI platform devices for Microchip PIC32.
+ *
+ * Copyright (C) 2015 Microchip
+ * Andrei Pistirica, Paul Thacker
+ *
+ * Inspired by sdhci-pltfm.c
+ *
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/mmc/host.h>
+#include <linux/io.h>
+#include "sdhci.h"
+#include "sdhci-pltfm.h"
+#include <linux/platform_data/sdhci-pic32.h>
+
+#define SDH_SHARED_BUS_CTRL 0x000000E0
+#define SDH_SHARED_BUS_NR_CLK_PINS_MASK 0x7
+#define SDH_SHARED_BUS_NR_IRQ_PINS_MASK 0x30
+#define SDH_SHARED_BUS_CLK_PINS 0x10
+#define SDH_SHARED_BUS_IRQ_PINS 0x14
+#define SDH_CAPS_SDH_SLOT_TYPE_MASK 0xC0000000
+#define SDH_SLOT_TYPE_REMOVABLE 0x0
+#define SDH_SLOT_TYPE_EMBEDDED 0x1
+#define SDH_SLOT_TYPE_SHARED_BUS 0x2
+#define SDHCI_CTRL_CDSSEL 0x80
+#define SDHCI_CTRL_CDTLVL 0x40
+
+#define ADMA_FIFO_RD_THSHLD 512
+#define ADMA_FIFO_WR_THSHLD 512
+
+struct pic32_sdhci_priv {
+ struct platform_device *pdev;
+ struct clk *sys_clk;
+ struct clk *base_clk;
+};
+
+static unsigned int pic32_sdhci_get_max_clock(struct sdhci_host *host)
+{
+ struct pic32_sdhci_priv *sdhci_pdata = sdhci_priv(host);
+
+ return clk_get_rate(sdhci_pdata->base_clk);
+}
+
+static void pic32_sdhci_set_bus_width(struct sdhci_host *host, int width)
+{
+ u8 ctrl;
+
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ if (width == MMC_BUS_WIDTH_8) {
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ if (host->version >= SDHCI_SPEC_300)
+ ctrl |= SDHCI_CTRL_8BITBUS;
+ } else {
+ if (host->version >= SDHCI_SPEC_300)
+ ctrl &= ~SDHCI_CTRL_8BITBUS;
+ if (width == MMC_BUS_WIDTH_4)
+ ctrl |= SDHCI_CTRL_4BITBUS;
+ else
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ }
+
+ /* CD select and test bits must be set for errata workaround. */
+ ctrl &= ~SDHCI_CTRL_CDTLVL;
+ ctrl |= SDHCI_CTRL_CDSSEL;
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+}
+
+static unsigned int pic32_sdhci_get_ro(struct sdhci_host *host)
+{
+ /*
+ * The SDHCI_WRITE_PROTECT bit is unstable on current hardware so we
+ * can't depend on its value in any way.
+ */
+ return 0;
+}
+
+static const struct sdhci_ops pic32_sdhci_ops = {
+ .get_max_clock = pic32_sdhci_get_max_clock,
+ .set_clock = sdhci_set_clock,
+ .set_bus_width = pic32_sdhci_set_bus_width,
+ .reset = sdhci_reset,
+ .set_uhs_signaling = sdhci_set_uhs_signaling,
+ .get_ro = pic32_sdhci_get_ro,
+};
+
+static struct sdhci_pltfm_data sdhci_pic32_pdata = {
+ .ops = &pic32_sdhci_ops,
+ .quirks = SDHCI_QUIRK_NO_HISPD_BIT,
+ .quirks2 = SDHCI_QUIRK2_NO_1_8_V,
+};
+
+static void pic32_sdhci_shared_bus(struct platform_device *pdev)
+{
+ struct sdhci_host *host = platform_get_drvdata(pdev);
+ u32 bus = readl(host->ioaddr + SDH_SHARED_BUS_CTRL);
+ u32 clk_pins = (bus & SDH_SHARED_BUS_NR_CLK_PINS_MASK) >> 0;
+ u32 irq_pins = (bus & SDH_SHARED_BUS_NR_IRQ_PINS_MASK) >> 4;
+
+ /* select first clock */
+ if (clk_pins & 1)
+ bus |= (1 << SDH_SHARED_BUS_CLK_PINS);
+
+ /* select first interrupt */
+ if (irq_pins & 1)
+ bus |= (1 << SDH_SHARED_BUS_IRQ_PINS);
+
+ writel(bus, host->ioaddr + SDH_SHARED_BUS_CTRL);
+}
+
+static int pic32_sdhci_probe_platform(struct platform_device *pdev,
+ struct pic32_sdhci_priv *pdata)
+{
+ int ret = 0;
+ u32 caps_slot_type;
+ struct sdhci_host *host = platform_get_drvdata(pdev);
+
+ /* Check card slot connected on shared bus. */
+ host->caps = readl(host->ioaddr + SDHCI_CAPABILITIES);
+ caps_slot_type = (host->caps & SDH_CAPS_SDH_SLOT_TYPE_MASK) >> 30;
+ if (caps_slot_type == SDH_SLOT_TYPE_SHARED_BUS)
+ pic32_sdhci_shared_bus(pdev);
+
+ return ret;
+}
+
+static int pic32_sdhci_probe(struct platform_device *pdev)
+{
+ struct sdhci_host *host;
+ struct sdhci_pltfm_host *pltfm_host;
+ struct pic32_sdhci_priv *sdhci_pdata;
+ struct pic32_sdhci_platform_data *plat_data;
+ int ret;
+
+ host = sdhci_pltfm_init(pdev, &sdhci_pic32_pdata,
+ sizeof(struct pic32_sdhci_priv));
+ if (IS_ERR(host)) {
+ ret = PTR_ERR(host);
+ goto err;
+ }
+
+ pltfm_host = sdhci_priv(host);
+ sdhci_pdata = sdhci_pltfm_priv(pltfm_host);
+
+ plat_data = pdev->dev.platform_data;
+ if (plat_data && plat_data->setup_dma) {
+ ret = plat_data->setup_dma(ADMA_FIFO_RD_THSHLD,
+ ADMA_FIFO_WR_THSHLD);
+ if (ret)
+ goto err_host;
+ }
+
+ sdhci_pdata->sys_clk = devm_clk_get(&pdev->dev, "sys_clk");
+ if (IS_ERR(sdhci_pdata->sys_clk)) {
+ ret = PTR_ERR(sdhci_pdata->sys_clk);
+ dev_err(&pdev->dev, "Error getting clock\n");
+ goto err_host;
+ }
+
+ ret = clk_prepare_enable(sdhci_pdata->sys_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Error enabling clock\n");
+ goto err_host;
+ }
+
+ sdhci_pdata->base_clk = devm_clk_get(&pdev->dev, "base_clk");
+ if (IS_ERR(sdhci_pdata->base_clk)) {
+ ret = PTR_ERR(sdhci_pdata->base_clk);
+ dev_err(&pdev->dev, "Error getting clock\n");
+ goto err_sys_clk;
+ }
+
+ ret = clk_prepare_enable(sdhci_pdata->base_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Error enabling clock\n");
+ goto err_base_clk;
+ }
+
+ ret = mmc_of_parse(host->mmc);
+ if (ret)
+ goto err_base_clk;
+
+ ret = pic32_sdhci_probe_platform(pdev, sdhci_pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to probe platform!\n");
+ goto err_base_clk;
+ }
+
+ ret = sdhci_add_host(host);
+ if (ret) {
+ dev_err(&pdev->dev, "error adding host\n");
+ goto err_base_clk;
+ }
+
+ dev_info(&pdev->dev, "Successfully added sdhci host\n");
+ return 0;
+
+err_base_clk:
+ clk_disable_unprepare(sdhci_pdata->base_clk);
+err_sys_clk:
+ clk_disable_unprepare(sdhci_pdata->sys_clk);
+err_host:
+ sdhci_pltfm_free(pdev);
+err:
+ dev_err(&pdev->dev, "pic32-sdhci probe failed: %d\n", ret);
+ return ret;
+}
+
+static int pic32_sdhci_remove(struct platform_device *pdev)
+{
+ struct sdhci_host *host = platform_get_drvdata(pdev);
+ struct pic32_sdhci_priv *sdhci_pdata = sdhci_priv(host);
+ u32 scratch;
+
+ scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
+ sdhci_remove_host(host, scratch == (u32)~0);
+ clk_disable_unprepare(sdhci_pdata->base_clk);
+ clk_disable_unprepare(sdhci_pdata->sys_clk);
+ sdhci_pltfm_free(pdev);
+
+ return 0;
+}
+
+static const struct of_device_id pic32_sdhci_id_table[] = {
+ { .compatible = "microchip,pic32mzda-sdhci" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pic32_sdhci_id_table);
+
+static struct platform_driver pic32_sdhci_driver = {
+ .driver = {
+ .name = "pic32-sdhci",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(pic32_sdhci_id_table),
+ },
+ .probe = pic32_sdhci_probe,
+ .remove = pic32_sdhci_remove,
+};
+
+module_platform_driver(pic32_sdhci_driver);
+
+MODULE_DESCRIPTION("Microchip PIC32 SDHCI driver");
+MODULE_AUTHOR("Pistirica Sorin Andrei & Sandeep Sheriker");
+MODULE_LICENSE("GPL v2");
projects / linux-beck.git / commitdiff