17866e14f3
On some Samsung SoCs not all SDHCI controllers have card detect (CD) line. For some embedded designs it is not even needed, because ususally the device (like SDIO flash memory or wifi controller) is permanently wired to the controller. There are also systems which have a card detect line connected to some of the external interrupt lines or the presence of the card depends on some other actions (like enabling a power regulator). This patch adds support for all these cases. The following card detection methods are possible: 1. internal sdhci host card detect line 2. external event 3. external gpio interrupt 4. no card detect line, controller will poll for the card 5. no card detect line, card is permanently wired to the controller (once detected host won't poll it any more) By default, all existing code would use method #1, what is compatible with the previous version of the driver. In case of external event, two callbacks must be provided in platdata: ext_cd_init and ext_cd_cleanup. Both of them get a callback to a function that notifies the s3c-sdhci host contoller as their argument. That callback function should be called from the even dispatcher to let host notice the card insertion/removal. In case of external gpio interrupt, a gpio pin number must be provided in platdata (ext_cd_gpio parameter), as well as the information about the polarity of that gpio pin (ext_cd_gpio_invert). By default (ext_cd_gpio_invert == 0) gpio value 0 means 'card has been removed', but this can be changed to 'card has been removed' when ext_cd_gpio_invert == 1. This patch adds all required changes to sdhci-s3c driver. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
551 lines
13 KiB
C
551 lines
13 KiB
C
/* linux/drivers/mmc/host/sdhci-s3c.c
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*
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* Copyright 2008 Openmoko Inc.
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* Copyright 2008 Simtec Electronics
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* Ben Dooks <ben@simtec.co.uk>
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* http://armlinux.simtec.co.uk/
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*
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* SDHCI (HSMMC) support for Samsung SoC
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/delay.h>
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#include <linux/dma-mapping.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/gpio.h>
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#include <linux/mmc/host.h>
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#include <plat/sdhci.h>
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#include <plat/regs-sdhci.h>
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#include "sdhci.h"
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#define MAX_BUS_CLK (4)
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/**
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* struct sdhci_s3c - S3C SDHCI instance
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* @host: The SDHCI host created
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* @pdev: The platform device we where created from.
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* @ioarea: The resource created when we claimed the IO area.
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* @pdata: The platform data for this controller.
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* @cur_clk: The index of the current bus clock.
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* @clk_io: The clock for the internal bus interface.
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* @clk_bus: The clocks that are available for the SD/MMC bus clock.
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*/
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struct sdhci_s3c {
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struct sdhci_host *host;
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struct platform_device *pdev;
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struct resource *ioarea;
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struct s3c_sdhci_platdata *pdata;
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unsigned int cur_clk;
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int ext_cd_irq;
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int ext_cd_gpio;
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struct clk *clk_io;
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struct clk *clk_bus[MAX_BUS_CLK];
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};
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static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
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{
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return sdhci_priv(host);
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}
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/**
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* get_curclk - convert ctrl2 register to clock source number
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* @ctrl2: Control2 register value.
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*/
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static u32 get_curclk(u32 ctrl2)
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{
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ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
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ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
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return ctrl2;
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}
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static void sdhci_s3c_check_sclk(struct sdhci_host *host)
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{
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struct sdhci_s3c *ourhost = to_s3c(host);
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u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
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if (get_curclk(tmp) != ourhost->cur_clk) {
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dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
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tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
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tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
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writel(tmp, host->ioaddr + 0x80);
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}
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}
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/**
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* sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
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* @host: The SDHCI host instance.
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*
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* Callback to return the maximum clock rate acheivable by the controller.
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*/
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static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
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{
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struct sdhci_s3c *ourhost = to_s3c(host);
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struct clk *busclk;
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unsigned int rate, max;
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int clk;
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/* note, a reset will reset the clock source */
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sdhci_s3c_check_sclk(host);
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for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
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busclk = ourhost->clk_bus[clk];
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if (!busclk)
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continue;
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rate = clk_get_rate(busclk);
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if (rate > max)
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max = rate;
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}
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return max;
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}
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/**
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* sdhci_s3c_consider_clock - consider one the bus clocks for current setting
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* @ourhost: Our SDHCI instance.
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* @src: The source clock index.
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* @wanted: The clock frequency wanted.
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*/
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static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
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unsigned int src,
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unsigned int wanted)
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{
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unsigned long rate;
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struct clk *clksrc = ourhost->clk_bus[src];
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int div;
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if (!clksrc)
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return UINT_MAX;
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rate = clk_get_rate(clksrc);
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for (div = 1; div < 256; div *= 2) {
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if ((rate / div) <= wanted)
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break;
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}
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dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
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src, rate, wanted, rate / div);
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return (wanted - (rate / div));
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}
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/**
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* sdhci_s3c_set_clock - callback on clock change
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* @host: The SDHCI host being changed
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* @clock: The clock rate being requested.
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*
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* When the card's clock is going to be changed, look at the new frequency
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* and find the best clock source to go with it.
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*/
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static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
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{
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struct sdhci_s3c *ourhost = to_s3c(host);
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unsigned int best = UINT_MAX;
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unsigned int delta;
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int best_src = 0;
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int src;
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u32 ctrl;
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/* don't bother if the clock is going off. */
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if (clock == 0)
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return;
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for (src = 0; src < MAX_BUS_CLK; src++) {
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delta = sdhci_s3c_consider_clock(ourhost, src, clock);
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if (delta < best) {
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best = delta;
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best_src = src;
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}
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}
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dev_dbg(&ourhost->pdev->dev,
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"selected source %d, clock %d, delta %d\n",
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best_src, clock, best);
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/* select the new clock source */
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if (ourhost->cur_clk != best_src) {
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struct clk *clk = ourhost->clk_bus[best_src];
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/* turn clock off to card before changing clock source */
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writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
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ourhost->cur_clk = best_src;
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host->max_clk = clk_get_rate(clk);
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ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
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ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
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ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
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writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
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}
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/* reconfigure the hardware for new clock rate */
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{
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struct mmc_ios ios;
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ios.clock = clock;
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if (ourhost->pdata->cfg_card)
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(ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
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&ios, NULL);
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}
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}
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/**
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* sdhci_s3c_get_min_clock - callback to get minimal supported clock value
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* @host: The SDHCI host being queried
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*
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* To init mmc host properly a minimal clock value is needed. For high system
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* bus clock's values the standard formula gives values out of allowed range.
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* The clock still can be set to lower values, if clock source other then
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* system bus is selected.
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*/
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static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
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{
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struct sdhci_s3c *ourhost = to_s3c(host);
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unsigned int delta, min = UINT_MAX;
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int src;
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for (src = 0; src < MAX_BUS_CLK; src++) {
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delta = sdhci_s3c_consider_clock(ourhost, src, 0);
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if (delta == UINT_MAX)
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continue;
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/* delta is a negative value in this case */
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if (-delta < min)
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min = -delta;
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}
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return min;
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}
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static struct sdhci_ops sdhci_s3c_ops = {
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.get_max_clock = sdhci_s3c_get_max_clk,
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.set_clock = sdhci_s3c_set_clock,
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.get_min_clock = sdhci_s3c_get_min_clock,
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};
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static void sdhci_s3c_notify_change(struct platform_device *dev, int state)
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{
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struct sdhci_host *host = platform_get_drvdata(dev);
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if (host) {
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mutex_lock(&host->lock);
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if (state) {
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dev_dbg(&dev->dev, "card inserted.\n");
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host->flags &= ~SDHCI_DEVICE_DEAD;
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host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
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} else {
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dev_dbg(&dev->dev, "card removed.\n");
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host->flags |= SDHCI_DEVICE_DEAD;
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host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
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}
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sdhci_card_detect(host);
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mutex_unlock(&host->lock);
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}
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}
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static irqreturn_t sdhci_s3c_gpio_card_detect_thread(int irq, void *dev_id)
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{
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struct sdhci_s3c *sc = dev_id;
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int status = gpio_get_value(sc->ext_cd_gpio);
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if (sc->pdata->ext_cd_gpio_invert)
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status = !status;
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sdhci_s3c_notify_change(sc->pdev, status);
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return IRQ_HANDLED;
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}
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static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
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{
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struct s3c_sdhci_platdata *pdata = sc->pdata;
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struct device *dev = &sc->pdev->dev;
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if (gpio_request(pdata->ext_cd_gpio, "SDHCI EXT CD") == 0) {
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sc->ext_cd_gpio = pdata->ext_cd_gpio;
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sc->ext_cd_irq = gpio_to_irq(pdata->ext_cd_gpio);
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if (sc->ext_cd_irq &&
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request_threaded_irq(sc->ext_cd_irq, NULL,
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sdhci_s3c_gpio_card_detect_thread,
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IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
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dev_name(dev), sc) == 0) {
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int status = gpio_get_value(sc->ext_cd_gpio);
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if (pdata->ext_cd_gpio_invert)
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status = !status;
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sdhci_s3c_notify_change(sc->pdev, status);
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} else {
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dev_warn(dev, "cannot request irq for card detect\n");
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sc->ext_cd_irq = 0;
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}
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} else {
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dev_err(dev, "cannot request gpio for card detect\n");
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}
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}
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static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
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{
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struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
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struct device *dev = &pdev->dev;
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struct sdhci_host *host;
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struct sdhci_s3c *sc;
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struct resource *res;
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int ret, irq, ptr, clks;
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if (!pdata) {
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dev_err(dev, "no device data specified\n");
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return -ENOENT;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(dev, "no irq specified\n");
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return irq;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(dev, "no memory specified\n");
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return -ENOENT;
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}
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host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
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if (IS_ERR(host)) {
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dev_err(dev, "sdhci_alloc_host() failed\n");
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return PTR_ERR(host);
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}
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sc = sdhci_priv(host);
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sc->host = host;
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sc->pdev = pdev;
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sc->pdata = pdata;
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sc->ext_cd_gpio = -1; /* invalid gpio number */
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platform_set_drvdata(pdev, host);
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sc->clk_io = clk_get(dev, "hsmmc");
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if (IS_ERR(sc->clk_io)) {
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dev_err(dev, "failed to get io clock\n");
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ret = PTR_ERR(sc->clk_io);
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goto err_io_clk;
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}
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/* enable the local io clock and keep it running for the moment. */
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clk_enable(sc->clk_io);
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for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
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struct clk *clk;
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char *name = pdata->clocks[ptr];
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if (name == NULL)
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continue;
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clk = clk_get(dev, name);
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if (IS_ERR(clk)) {
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dev_err(dev, "failed to get clock %s\n", name);
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continue;
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}
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clks++;
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sc->clk_bus[ptr] = clk;
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clk_enable(clk);
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dev_info(dev, "clock source %d: %s (%ld Hz)\n",
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ptr, name, clk_get_rate(clk));
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}
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if (clks == 0) {
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dev_err(dev, "failed to find any bus clocks\n");
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ret = -ENOENT;
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goto err_no_busclks;
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}
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sc->ioarea = request_mem_region(res->start, resource_size(res),
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mmc_hostname(host->mmc));
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if (!sc->ioarea) {
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dev_err(dev, "failed to reserve register area\n");
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ret = -ENXIO;
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goto err_req_regs;
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}
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host->ioaddr = ioremap_nocache(res->start, resource_size(res));
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if (!host->ioaddr) {
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dev_err(dev, "failed to map registers\n");
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ret = -ENXIO;
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goto err_req_regs;
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}
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/* Ensure we have minimal gpio selected CMD/CLK/Detect */
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if (pdata->cfg_gpio)
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pdata->cfg_gpio(pdev, pdata->max_width);
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host->hw_name = "samsung-hsmmc";
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host->ops = &sdhci_s3c_ops;
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host->quirks = 0;
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host->irq = irq;
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/* Setup quirks for the controller */
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host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
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host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
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#ifndef CONFIG_MMC_SDHCI_S3C_DMA
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/* we currently see overruns on errors, so disable the SDMA
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* support as well. */
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host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
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#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
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/* It seems we do not get an DATA transfer complete on non-busy
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* transfers, not sure if this is a problem with this specific
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* SDHCI block, or a missing configuration that needs to be set. */
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host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
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if (pdata->cd_type == S3C_SDHCI_CD_NONE ||
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pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
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host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
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if (pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
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host->mmc->caps = MMC_CAP_NONREMOVABLE;
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host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
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SDHCI_QUIRK_32BIT_DMA_SIZE);
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/* HSMMC on Samsung SoCs uses SDCLK as timeout clock */
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host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;
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ret = sdhci_add_host(host);
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if (ret) {
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dev_err(dev, "sdhci_add_host() failed\n");
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goto err_add_host;
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}
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/* The following two methods of card detection might call
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sdhci_s3c_notify_change() immediately, so they can be called
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only after sdhci_add_host(). Setup errors are ignored. */
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if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_init)
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pdata->ext_cd_init(&sdhci_s3c_notify_change);
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if (pdata->cd_type == S3C_SDHCI_CD_GPIO &&
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gpio_is_valid(pdata->ext_cd_gpio))
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sdhci_s3c_setup_card_detect_gpio(sc);
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return 0;
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err_add_host:
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release_resource(sc->ioarea);
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kfree(sc->ioarea);
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err_req_regs:
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for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
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clk_disable(sc->clk_bus[ptr]);
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clk_put(sc->clk_bus[ptr]);
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}
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err_no_busclks:
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clk_disable(sc->clk_io);
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clk_put(sc->clk_io);
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err_io_clk:
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sdhci_free_host(host);
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return ret;
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}
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static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
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{
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struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
|
|
struct sdhci_host *host = platform_get_drvdata(pdev);
|
|
struct sdhci_s3c *sc = sdhci_priv(host);
|
|
int ptr;
|
|
|
|
if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
|
|
pdata->ext_cd_cleanup(&sdhci_s3c_notify_change);
|
|
|
|
if (sc->ext_cd_irq)
|
|
free_irq(sc->ext_cd_irq, sc);
|
|
|
|
if (gpio_is_valid(sc->ext_cd_gpio))
|
|
gpio_free(sc->ext_cd_gpio);
|
|
|
|
sdhci_remove_host(host, 1);
|
|
|
|
for (ptr = 0; ptr < 3; ptr++) {
|
|
clk_disable(sc->clk_bus[ptr]);
|
|
clk_put(sc->clk_bus[ptr]);
|
|
}
|
|
clk_disable(sc->clk_io);
|
|
clk_put(sc->clk_io);
|
|
|
|
iounmap(host->ioaddr);
|
|
release_resource(sc->ioarea);
|
|
kfree(sc->ioarea);
|
|
|
|
sdhci_free_host(host);
|
|
platform_set_drvdata(pdev, NULL);
|
|
|
|
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");
|