* [PATCH 3/5] Revamped U300 padmux API
@ 2009-09-17 12:07 Linus Walleij
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From: Linus Walleij @ 2009-09-17 12:07 UTC (permalink / raw)
To: linux-arm-kernel
This abstracts the hackish padmux API on the U300 platform into
something more manageable. It provides a way for drivers to
activate/deactivate a certain padmux setting. It will also switch
the users of the old API over to using the new style, pushing
muxing into the apropriate setup files.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
---
arch/arm/mach-u300/gpio.c | 13 --
arch/arm/mach-u300/mmc.c | 16 ++
arch/arm/mach-u300/padmux.c | 395 ++++++++++++++++++++++++++++++++++++++-----
arch/arm/mach-u300/padmux.h | 28 +++-
4 files changed, 392 insertions(+), 60 deletions(-)
diff --git a/arch/arm/mach-u300/gpio.c b/arch/arm/mach-u300/gpio.c
index 308cdb1..63c8f27 100644
--- a/arch/arm/mach-u300/gpio.c
+++ b/arch/arm/mach-u300/gpio.c
@@ -25,11 +25,6 @@
#include <linux/platform_device.h>
#include <linux/gpio.h>
-/* Need access to SYSCON registers for PADmuxing */
-#include <mach/syscon.h>
-
-#include "padmux.h"
-
/* Reference to GPIO block clock */
static struct clk *clk;
@@ -606,14 +601,6 @@ static int __init gpio_probe(struct platform_device *pdev)
writel(U300_GPIO_CR_BLOCK_CLKRQ_ENABLE, virtbase + U300_GPIO_CR);
#endif
- /* Set up some padmuxing here */
-#ifdef CONFIG_MMC
- pmx_set_mission_mode_mmc();
-#endif
-#ifdef CONFIG_SPI_PL022
- pmx_set_mission_mode_spi();
-#endif
-
gpio_set_initial_values();
for (num_irqs = 0 ; num_irqs < U300_GPIO_NUM_PORTS; num_irqs++) {
diff --git a/arch/arm/mach-u300/mmc.c b/arch/arm/mach-u300/mmc.c
index bbfcb1a..70f0ca5 100644
--- a/arch/arm/mach-u300/mmc.c
+++ b/arch/arm/mach-u300/mmc.c
@@ -22,6 +22,7 @@
#include <linux/amba/mmci.h>
#include "mmc.h"
+#include "padmux.h"
struct mmci_card_event {
struct input_dev *mmc_input;
@@ -146,6 +147,7 @@ int __devinit mmc_init(struct amba_device *adev)
{
struct mmci_card_event *mmci_card;
struct device *mmcsd_device = &adev->dev;
+ struct pmx *pmx;
int ret = 0;
mmci_card = kzalloc(sizeof(struct mmci_card_event), GFP_KERNEL);
@@ -209,6 +211,20 @@ int __devinit mmc_init(struct amba_device *adev)
input_set_drvdata(mmci_card->mmc_input, mmci_card);
+ /*
+ * Setup padmuxing for MMC. Since this must always be
+ * compiled into the kernel, pmx is never released.
+ */
+ pmx = pmx_get(mmcsd_device, U300_APP_PMX_MMC_SETTING);
+
+ if (IS_ERR(pmx))
+ pr_warning("Could not get padmux handle\n");
+ else {
+ ret = pmx_activate(mmcsd_device, pmx);
+ if (IS_ERR_VALUE(ret))
+ pr_warning("Could not activate padmuxing\n");
+ }
+
ret = gpio_register_callback(U300_GPIO_PIN_MMC_CD, mmci_callback,
mmci_card);
diff --git a/arch/arm/mach-u300/padmux.c b/arch/arm/mach-u300/padmux.c
index f366456..4c93c6c 100644
--- a/arch/arm/mach-u300/padmux.c
+++ b/arch/arm/mach-u300/padmux.c
@@ -6,53 +6,362 @@
* Copyright (C) 2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
* U300 PADMUX functions
- * Author: Linus Walleij <linus.walleij@stericsson.com>
- *
+ * Author: Martin Persson <martin.persson@stericsson.com>
*/
-#include <linux/io.h>
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/bug.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
#include <mach/u300-regs.h>
#include <mach/syscon.h>
-
#include "padmux.h"
-/* Set the PAD MUX to route the MMC reader correctly to GPIO0. */
-void pmx_set_mission_mode_mmc(void)
-{
- u16 val;
-
- val = readw(U300_SYSCON_VBASE + U300_SYSCON_PMC1LR);
- val &= ~U300_SYSCON_PMC1LR_MMCSD_MASK;
- writew(val, U300_SYSCON_VBASE + U300_SYSCON_PMC1LR);
- val = readw(U300_SYSCON_VBASE + U300_SYSCON_PMC1HR);
- val &= ~U300_SYSCON_PMC1HR_APP_GPIO_1_MASK;
- val |= U300_SYSCON_PMC1HR_APP_GPIO_1_MMC;
- writew(val, U300_SYSCON_VBASE + U300_SYSCON_PMC1HR);
-}
-
-void pmx_set_mission_mode_spi(void)
-{
- u16 val;
-
- /* Set up padmuxing so the SPI port and its chipselects are active */
- val = readw(U300_SYSCON_VBASE + U300_SYSCON_PMC1HR);
- /*
- * Activate the SPI port (disable the use of these pins for generic
- * GPIO, DSP, AAIF
- */
- val &= ~U300_SYSCON_PMC1HR_APP_SPI_2_MASK;
- val |= U300_SYSCON_PMC1HR_APP_SPI_2_SPI;
- /*
- * Use GPIO pin SPI CS1 for CS1 actually (it can be used for other
- * things also)
- */
- val &= ~U300_SYSCON_PMC1HR_APP_SPI_CS_1_MASK;
- val |= U300_SYSCON_PMC1HR_APP_SPI_CS_1_SPI;
- /*
- * Use GPIO pin SPI CS2 for CS2 actually (it can be used for other
- * things also)
- */
- val &= ~U300_SYSCON_PMC1HR_APP_SPI_CS_2_MASK;
- val |= U300_SYSCON_PMC1HR_APP_SPI_CS_2_SPI;
- writew(val, U300_SYSCON_VBASE + U300_SYSCON_PMC1HR);
+static DEFINE_MUTEX(pmx_mutex);
+
+const u32 pmx_registers[] = {
+ (U300_SYSCON_VBASE + U300_SYSCON_PMC1LR),
+ (U300_SYSCON_VBASE + U300_SYSCON_PMC1HR),
+ (U300_SYSCON_VBASE + U300_SYSCON_PMC2R),
+ (U300_SYSCON_VBASE + U300_SYSCON_PMC3R),
+ (U300_SYSCON_VBASE + U300_SYSCON_PMC4R)
+};
+
+/* High level functionality */
+
+/* Lazy dog:
+ * onmask = {
+ * {"PMC1LR" mask, "PMC1LR" value},
+ * {"PMC1HR" mask, "PMC1HR" value},
+ * {"PMC2R" mask, "PMC2R" value},
+ * {"PMC3R" mask, "PMC3R" value},
+ * {"PMC4R" mask, "PMC4R" value}
+ * }
+ */
+static struct pmx mmc_setting = {
+ .setting = U300_APP_PMX_MMC_SETTING,
+ .default_on = false,
+ .activated = false,
+ .name = "MMC",
+ .onmask = {
+ {U300_SYSCON_PMC1LR_MMCSD_MASK,
+ U300_SYSCON_PMC1LR_MMCSD_MMCSD},
+ {0, 0},
+ {0, 0},
+ {0, 0},
+ {U300_SYSCON_PMC4R_APP_MISC_12_MASK,
+ U300_SYSCON_PMC4R_APP_MISC_12_APP_GPIO}
+ },
+};
+
+static struct pmx spi_setting = {
+ .setting = U300_APP_PMX_SPI_SETTING,
+ .default_on = false,
+ .activated = false,
+ .name = "SPI",
+ .onmask = {{0, 0},
+ {U300_SYSCON_PMC1HR_APP_SPI_2_MASK |
+ U300_SYSCON_PMC1HR_APP_SPI_CS_1_MASK |
+ U300_SYSCON_PMC1HR_APP_SPI_CS_2_MASK,
+ U300_SYSCON_PMC1HR_APP_SPI_2_SPI |
+ U300_SYSCON_PMC1HR_APP_SPI_CS_1_SPI |
+ U300_SYSCON_PMC1HR_APP_SPI_CS_2_SPI},
+ {0, 0},
+ {0, 0},
+ {0, 0}
+ },
+};
+
+/* Available padmux settings */
+static struct pmx *pmx_settings[] = {
+ &mmc_setting,
+ &spi_setting,
+};
+
+static void update_registers(struct pmx *pmx, bool activate)
+{
+ u16 regval, val, mask;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(pmx_registers); i++) {
+ if (activate)
+ val = pmx->onmask[i].val;
+ else
+ val = 0;
+
+ mask = pmx->onmask[i].mask;
+ if (mask != 0) {
+ regval = readw(pmx_registers[i]);
+ regval &= ~mask;
+ regval |= val;
+ writew(regval, pmx_registers[i]);
+ }
+ }
+}
+
+struct pmx *pmx_get(struct device *dev, enum pmx_settings setting)
+{
+ int i;
+ struct pmx *pmx = ERR_PTR(-ENOENT);
+
+ if (dev == NULL)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&pmx_mutex);
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+
+ if (setting == pmx_settings[i]->setting) {
+
+ if (pmx_settings[i]->dev != NULL) {
+ WARN(1, "padmux: required setting "
+ "in use by another consumer\n");
+ } else {
+ pmx = pmx_settings[i];
+ pmx->dev = dev;
+ dev_dbg(dev, "padmux: setting nr %d is now "
+ "bound to %s and ready to use\n",
+ setting, dev_name(dev));
+ break;
+ }
+ }
+ }
+ mutex_unlock(&pmx_mutex);
+
+ return pmx;
+}
+EXPORT_SYMBOL(pmx_get);
+
+int pmx_put(struct device *dev, struct pmx *pmx)
+{
+ int i;
+ int ret = -ENOENT;
+
+ if (pmx == NULL || dev == NULL)
+ return -EINVAL;
+
+ mutex_lock(&pmx_mutex);
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+
+ if (pmx->setting == pmx_settings[i]->setting) {
+
+ if (dev != pmx->dev) {
+ WARN(1, "padmux: cannot release handle as "
+ "it is bound to another consumer\n");
+ ret = -EINVAL;
+ break;
+ } else {
+ pmx_settings[i]->dev = NULL;
+ ret = 0;
+ break;
+ }
+ }
+ }
+ mutex_unlock(&pmx_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(pmx_put);
+
+int pmx_activate(struct device *dev, struct pmx *pmx)
+{
+ int i, j, ret;
+ ret = 0;
+
+ if (pmx == NULL || dev == NULL)
+ return -EINVAL;
+
+ mutex_lock(&pmx_mutex);
+
+ /* Make sure the required bits are not used */
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+
+ if (pmx_settings[i]->dev == NULL || pmx_settings[i] == pmx)
+ continue;
+
+ for (j = 0; j < ARRAY_SIZE(pmx_registers); j++) {
+
+ if (pmx_settings[i]->onmask[j].mask & pmx->
+ onmask[j].mask) {
+ /* More than one entry on the same bits */
+ WARN(1, "padmux: cannot activate "
+ "setting. Bit conflict with "
+ "an active setting\n");
+
+ ret = -EUSERS;
+ goto exit;
+ }
+ }
+ }
+ update_registers(pmx, true);
+ pmx->activated = true;
+ dev_dbg(dev, "padmux: setting nr %d is activated\n",
+ pmx->setting);
+
+exit:
+ mutex_unlock(&pmx_mutex);
+ return ret;
+}
+EXPORT_SYMBOL(pmx_activate);
+
+int pmx_deactivate(struct device *dev, struct pmx *pmx)
+{
+ int i;
+ int ret = -ENOENT;
+
+ if (pmx == NULL || dev == NULL)
+ return -EINVAL;
+
+ mutex_lock(&pmx_mutex);
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+
+ if (pmx_settings[i]->dev == NULL)
+ continue;
+
+ if (pmx->setting == pmx_settings[i]->setting) {
+
+ if (dev != pmx->dev) {
+ WARN(1, "padmux: cannot deactivate "
+ "pmx setting as it was activated "
+ "by another consumer\n");
+
+ ret = -EBUSY;
+ continue;
+ } else {
+ update_registers(pmx, false);
+ pmx_settings[i]->dev = NULL;
+ pmx->activated = false;
+ ret = 0;
+ dev_dbg(dev, "padmux: setting nr %d is deactivated",
+ pmx->setting);
+ break;
+ }
+ }
+ }
+ mutex_unlock(&pmx_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(pmx_deactivate);
+
+/*
+ * For internal use only. If it is to be exported,
+ * it should be reentrant. Notice that pmx_activate
+ * (i.e. runtime settings) always override default settings.
+ */
+static int pmx_set_default(void)
+{
+ /* Used to identify several entries on the same bits */
+ u16 modbits[ARRAY_SIZE(pmx_registers)];
+
+ int i, j;
+
+ memset(modbits, 0, ARRAY_SIZE(pmx_registers) * sizeof(u16));
+
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+
+ if (!pmx_settings[i]->default_on)
+ continue;
+
+ for (j = 0; j < ARRAY_SIZE(pmx_registers); j++) {
+
+ /* Make sure there is only one entry on the same bits */
+ if (modbits[j] & pmx_settings[i]->onmask[j].mask) {
+ BUG();
+ return -EUSERS;
+ }
+ modbits[j] |= pmx_settings[i]->onmask[j].mask;
+ }
+ update_registers(pmx_settings[i], true);
+ }
+ return 0;
}
+
+#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_U300_DEBUG))
+static int pmx_show(struct seq_file *s, void *data)
+{
+ int i;
+ seq_printf(s, "-------------------------------------------------\n");
+ seq_printf(s, "SETTING BOUND TO DEVICE STATE\n");
+ seq_printf(s, "-------------------------------------------------\n");
+ mutex_lock(&pmx_mutex);
+ for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) {
+ /* Format pmx and device name nicely */
+ char cdp[33];
+ int chars;
+
+ chars = snprintf(&cdp[0], 17, "%s", pmx_settings[i]->name);
+ while (chars < 16) {
+ cdp[chars] = ' ';
+ chars++;
+ }
+ chars = snprintf(&cdp[16], 17, "%s", pmx_settings[i]->dev ?
+ dev_name(pmx_settings[i]->dev) : "N/A");
+ while (chars < 16) {
+ cdp[chars+16] = ' ';
+ chars++;
+ }
+ cdp[32] = '\0';
+
+ seq_printf(s,
+ "%s\t%s\n",
+ &cdp[0],
+ pmx_settings[i]->activated ?
+ "ACTIVATED" : "DEACTIVATED"
+ );
+
+ }
+ mutex_unlock(&pmx_mutex);
+ return 0;
+}
+
+static int pmx_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pmx_show, NULL);
+}
+
+static const struct file_operations pmx_operations = {
+ .owner = THIS_MODULE,
+ .open = pmx_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init init_pmx_read_debugfs(void)
+{
+ /* Expose a simple debugfs interface to view pmx settings */
+ (void) debugfs_create_file("padmux", S_IFREG | S_IRUGO,
+ NULL, NULL,
+ &pmx_operations);
+ return 0;
+}
+
+/*
+ * This needs to come in after the core_initcall(),
+ * because debugfs is not available until
+ * the subsystems come up.
+ */
+module_init(init_pmx_read_debugfs);
+#endif
+
+static int __init pmx_init(void)
+{
+ int ret;
+
+ ret = pmx_set_default();
+
+ if (IS_ERR_VALUE(ret))
+ pr_crit("padmux: default settings could not be set\n");
+
+ return 0;
+}
+
+/* Should be initialized before consumers */
+core_initcall(pmx_init);
diff --git a/arch/arm/mach-u300/padmux.h b/arch/arm/mach-u300/padmux.h
index 8c2099a..6e8b860 100644
--- a/arch/arm/mach-u300/padmux.h
+++ b/arch/arm/mach-u300/padmux.h
@@ -6,14 +6,34 @@
* Copyright (C) 2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
* U300 PADMUX API
- * Author: Linus Walleij <linus.walleij@stericsson.com>
- *
+ * Author: Martin Persson <martin.persson@stericsson.com>
*/
#ifndef __MACH_U300_PADMUX_H
#define __MACH_U300_PADMUX_H
-void pmx_set_mission_mode_mmc(void);
-void pmx_set_mission_mode_spi(void);
+enum pmx_settings {
+ U300_APP_PMX_MMC_SETTING,
+ U300_APP_PMX_SPI_SETTING
+};
+
+struct pmx_onmask {
+ u16 mask; /* Mask bits */
+ u16 val; /* Value when active */
+};
+
+struct pmx {
+ struct device *dev;
+ enum pmx_settings setting;
+ char *name;
+ bool activated;
+ bool default_on;
+ struct pmx_onmask onmask[];
+};
+
+struct pmx *pmx_get(struct device *dev, enum pmx_settings setting);
+int pmx_put(struct device *dev, struct pmx *pmx);
+int pmx_activate(struct device *dev, struct pmx *pmx);
+int pmx_deactivate(struct device *dev, struct pmx *pmx);
#endif
--
1.6.2.1
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2009-09-17 12:07 [PATCH 3/5] Revamped U300 padmux API Linus Walleij
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