diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-pic32.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-pic32.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-pic32.c b/drivers/mmc/host/sdhci-pic32.c new file mode 100644 index 000000000..6ce1519ae --- /dev/null +++ b/drivers/mmc/host/sdhci-pic32.c @@ -0,0 +1,255 @@ +/* + * 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 const 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) + 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", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .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"); |