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linux/drivers/mfd/ti-ssp.c
Mark Brown 55692af5eb mfd: core: Push irqdomain mapping out into devices 
Currently the MFD core supports remapping MFD cell interrupts using an
irqdomain but only if the MFD is being instantiated using device tree
and only if the device tree bindings use the pattern of registering IPs
in the device tree with compatible properties.  This will be actively
harmful for drivers which support non-DT platforms and use this pattern
for their DT bindings as it will mean that the core will silently change
remapping behaviour and it is also limiting for drivers which don't do
DT with this particular pattern.  There is also a potential fragility if
there are interrupts not associated with MFD cells and all the cells are
omitted from the device tree for some reason.

Instead change the code to take an IRQ domain as an optional argument,
allowing drivers to take the decision about the parent domain for their
interrupts.  The one current user of this feature is ab8500-core, it has
the domain lookup pushed out into the driver.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-09-14 09:51:54 +02:00

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/*
* Sequencer Serial Port (SSP) driver for Texas Instruments' SoCs
*
* Copyright (C) 2010 Texas Instruments Inc
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mfd/core.h>
#include <linux/mfd/ti_ssp.h>
/* Register Offsets */
#define REG_REV 0x00
#define REG_IOSEL_1 0x04
#define REG_IOSEL_2 0x08
#define REG_PREDIV 0x0c
#define REG_INTR_ST 0x10
#define REG_INTR_EN 0x14
#define REG_TEST_CTRL 0x18
/* Per port registers */
#define PORT_CFG_2 0x00
#define PORT_ADDR 0x04
#define PORT_DATA 0x08
#define PORT_CFG_1 0x0c
#define PORT_STATE 0x10
#define SSP_PORT_CONFIG_MASK (SSP_EARLY_DIN | SSP_DELAY_DOUT)
#define SSP_PORT_CLKRATE_MASK 0x0f
#define SSP_SEQRAM_WR_EN BIT(4)
#define SSP_SEQRAM_RD_EN BIT(5)
#define SSP_START BIT(15)
#define SSP_BUSY BIT(10)
#define SSP_PORT_ASL BIT(7)
#define SSP_PORT_CFO1 BIT(6)
#define SSP_PORT_SEQRAM_SIZE 32
static const int ssp_port_base[] = {0x040, 0x080};
static const int ssp_port_seqram[] = {0x100, 0x180};
struct ti_ssp {
struct resource *res;
struct device *dev;
void __iomem *regs;
spinlock_t lock;
struct clk *clk;
int irq;
wait_queue_head_t wqh;
/*
* Some of the iosel2 register bits always read-back as 0, we need to
* remember these values so that we don't clobber previously set
* values.
*/
u32 iosel2;
};
static inline struct ti_ssp *dev_to_ssp(struct device *dev)
{
return dev_get_drvdata(dev->parent);
}
static inline int dev_to_port(struct device *dev)
{
return to_platform_device(dev)->id;
}
/* Register Access Helpers, rmw() functions need to run locked */
static inline u32 ssp_read(struct ti_ssp *ssp, int reg)
{
return __raw_readl(ssp->regs + reg);
}
static inline void ssp_write(struct ti_ssp *ssp, int reg, u32 val)
{
__raw_writel(val, ssp->regs + reg);
}
static inline void ssp_rmw(struct ti_ssp *ssp, int reg, u32 mask, u32 bits)
{
ssp_write(ssp, reg, (ssp_read(ssp, reg) & ~mask) | bits);
}
static inline u32 ssp_port_read(struct ti_ssp *ssp, int port, int reg)
{
return ssp_read(ssp, ssp_port_base[port] + reg);
}
static inline void ssp_port_write(struct ti_ssp *ssp, int port, int reg,
u32 val)
{
ssp_write(ssp, ssp_port_base[port] + reg, val);
}
static inline void ssp_port_rmw(struct ti_ssp *ssp, int port, int reg,
u32 mask, u32 bits)
{
ssp_rmw(ssp, ssp_port_base[port] + reg, mask, bits);
}
static inline void ssp_port_clr_bits(struct ti_ssp *ssp, int port, int reg,
u32 bits)
{
ssp_port_rmw(ssp, port, reg, bits, 0);
}
static inline void ssp_port_set_bits(struct ti_ssp *ssp, int port, int reg,
u32 bits)
{
ssp_port_rmw(ssp, port, reg, 0, bits);
}
/* Called to setup port clock mode, caller must hold ssp->lock */
static int __set_mode(struct ti_ssp *ssp, int port, int mode)
{
mode &= SSP_PORT_CONFIG_MASK;
ssp_port_rmw(ssp, port, PORT_CFG_1, SSP_PORT_CONFIG_MASK, mode);
return 0;
}
int ti_ssp_set_mode(struct device *dev, int mode)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev);
int ret;
spin_lock(&ssp->lock);
ret = __set_mode(ssp, port, mode);
spin_unlock(&ssp->lock);
return ret;
}
EXPORT_SYMBOL(ti_ssp_set_mode);
/* Called to setup iosel2, caller must hold ssp->lock */
static void __set_iosel2(struct ti_ssp *ssp, u32 mask, u32 val)
{
ssp->iosel2 = (ssp->iosel2 & ~mask) | val;
ssp_write(ssp, REG_IOSEL_2, ssp->iosel2);
}
/* Called to setup port iosel, caller must hold ssp->lock */
static void __set_iosel(struct ti_ssp *ssp, int port, u32 iosel)
{
unsigned val, shift = port ? 16 : 0;
/* IOSEL1 gets the least significant 16 bits */
val = ssp_read(ssp, REG_IOSEL_1);
val &= 0xffff << (port ? 0 : 16);
val |= (iosel & 0xffff) << (port ? 16 : 0);
ssp_write(ssp, REG_IOSEL_1, val);
/* IOSEL2 gets the most significant 16 bits */
val = (iosel >> 16) & 0x7;
__set_iosel2(ssp, 0x7 << shift, val << shift);
}
int ti_ssp_set_iosel(struct device *dev, u32 iosel)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev);
spin_lock(&ssp->lock);
__set_iosel(ssp, port, iosel);
spin_unlock(&ssp->lock);
return 0;
}
EXPORT_SYMBOL(ti_ssp_set_iosel);
int ti_ssp_load(struct device *dev, int offs, u32* prog, int len)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev);
int i;
if (len > SSP_PORT_SEQRAM_SIZE)
return -ENOSPC;
spin_lock(&ssp->lock);
/* Enable SeqRAM access */
ssp_port_set_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN);
/* Copy code */
for (i = 0; i < len; i++) {
__raw_writel(prog[i], ssp->regs + offs + 4*i +
ssp_port_seqram[port]);
}
/* Disable SeqRAM access */
ssp_port_clr_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN);
spin_unlock(&ssp->lock);
return 0;
}
EXPORT_SYMBOL(ti_ssp_load);
int ti_ssp_raw_read(struct device *dev)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev);
int shift = port ? 27 : 11;
return (ssp_read(ssp, REG_IOSEL_2) >> shift) & 0xf;
}
EXPORT_SYMBOL(ti_ssp_raw_read);
int ti_ssp_raw_write(struct device *dev, u32 val)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev), shift;
spin_lock(&ssp->lock);
shift = port ? 22 : 6;
val &= 0xf;
__set_iosel2(ssp, 0xf << shift, val << shift);
spin_unlock(&ssp->lock);
return 0;
}
EXPORT_SYMBOL(ti_ssp_raw_write);
static inline int __xfer_done(struct ti_ssp *ssp, int port)
{
return !(ssp_port_read(ssp, port, PORT_CFG_1) & SSP_BUSY);
}
int ti_ssp_run(struct device *dev, u32 pc, u32 input, u32 *output)
{
struct ti_ssp *ssp = dev_to_ssp(dev);
int port = dev_to_port(dev);
int ret;
if (pc & ~(0x3f))
return -EINVAL;
/* Grab ssp->lock to serialize rmw on ssp registers */
spin_lock(&ssp->lock);
ssp_port_write(ssp, port, PORT_ADDR, input >> 16);
ssp_port_write(ssp, port, PORT_DATA, input & 0xffff);
ssp_port_rmw(ssp, port, PORT_CFG_1, 0x3f, pc);
/* grab wait queue head lock to avoid race with the isr */
spin_lock_irq(&ssp->wqh.lock);
/* kick off sequence execution in hardware */
ssp_port_set_bits(ssp, port, PORT_CFG_1, SSP_START);
/* drop ssp lock; no register writes beyond this */
spin_unlock(&ssp->lock);
ret = wait_event_interruptible_locked_irq(ssp->wqh,
__xfer_done(ssp, port));
spin_unlock_irq(&ssp->wqh.lock);
if (ret < 0)
return ret;
if (output) {
*output = (ssp_port_read(ssp, port, PORT_ADDR) << 16) |
(ssp_port_read(ssp, port, PORT_DATA) & 0xffff);
}
ret = ssp_port_read(ssp, port, PORT_STATE) & 0x3f; /* stop address */
return ret;
}
EXPORT_SYMBOL(ti_ssp_run);
static irqreturn_t ti_ssp_interrupt(int irq, void *dev_data)
{
struct ti_ssp *ssp = dev_data;
spin_lock(&ssp->wqh.lock);
ssp_write(ssp, REG_INTR_ST, 0x3);
wake_up_locked(&ssp->wqh);
spin_unlock(&ssp->wqh.lock);
return IRQ_HANDLED;
}
static int __devinit ti_ssp_probe(struct platform_device *pdev)
{
static struct ti_ssp *ssp;
const struct ti_ssp_data *pdata = pdev->dev.platform_data;
int error = 0, prediv = 0xff, id;
unsigned long sysclk;
struct device *dev = &pdev->dev;
struct mfd_cell cells[2];
ssp = kzalloc(sizeof(*ssp), GFP_KERNEL);
if (!ssp) {
dev_err(dev, "cannot allocate device info\n");
return -ENOMEM;
}
ssp->dev = dev;
dev_set_drvdata(dev, ssp);
ssp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!ssp->res) {
error = -ENODEV;
dev_err(dev, "cannot determine register area\n");
goto error_res;
}
if (!request_mem_region(ssp->res->start, resource_size(ssp->res),
pdev->name)) {
error = -ENOMEM;
dev_err(dev, "cannot claim register memory\n");
goto error_res;
}
ssp->regs = ioremap(ssp->res->start, resource_size(ssp->res));
if (!ssp->regs) {
error = -ENOMEM;
dev_err(dev, "cannot map register memory\n");
goto error_map;
}
ssp->clk = clk_get(dev, NULL);
if (IS_ERR(ssp->clk)) {
error = PTR_ERR(ssp->clk);
dev_err(dev, "cannot claim device clock\n");
goto error_clk;
}
ssp->irq = platform_get_irq(pdev, 0);
if (ssp->irq < 0) {
error = -ENODEV;
dev_err(dev, "unknown irq\n");
goto error_irq;
}
error = request_threaded_irq(ssp->irq, NULL, ti_ssp_interrupt, 0,
dev_name(dev), ssp);
if (error < 0) {
dev_err(dev, "cannot acquire irq\n");
goto error_irq;
}
spin_lock_init(&ssp->lock);
init_waitqueue_head(&ssp->wqh);
/* Power on and initialize SSP */
error = clk_enable(ssp->clk);
if (error) {
dev_err(dev, "cannot enable device clock\n");
goto error_enable;
}
/* Reset registers to a sensible known state */
ssp_write(ssp, REG_IOSEL_1, 0);
ssp_write(ssp, REG_IOSEL_2, 0);
ssp_write(ssp, REG_INTR_EN, 0x3);
ssp_write(ssp, REG_INTR_ST, 0x3);
ssp_write(ssp, REG_TEST_CTRL, 0);
ssp_port_write(ssp, 0, PORT_CFG_1, SSP_PORT_ASL);
ssp_port_write(ssp, 1, PORT_CFG_1, SSP_PORT_ASL);
ssp_port_write(ssp, 0, PORT_CFG_2, SSP_PORT_CFO1);
ssp_port_write(ssp, 1, PORT_CFG_2, SSP_PORT_CFO1);
sysclk = clk_get_rate(ssp->clk);
if (pdata && pdata->out_clock)
prediv = (sysclk / pdata->out_clock) - 1;
prediv = clamp(prediv, 0, 0xff);
ssp_rmw(ssp, REG_PREDIV, 0xff, prediv);
memset(cells, 0, sizeof(cells));
for (id = 0; id < 2; id++) {
const struct ti_ssp_dev_data *data = &pdata->dev_data[id];
cells[id].id = id;
cells[id].name = data->dev_name;
cells[id].platform_data = data->pdata;
cells[id].data_size = data->pdata_size;
}
error = mfd_add_devices(dev, 0, cells, 2, NULL, 0, NULL);
if (error < 0) {
dev_err(dev, "cannot add mfd cells\n");
goto error_enable;
}
return 0;
error_enable:
free_irq(ssp->irq, ssp);
error_irq:
clk_put(ssp->clk);
error_clk:
iounmap(ssp->regs);
error_map:
release_mem_region(ssp->res->start, resource_size(ssp->res));
error_res:
kfree(ssp);
return error;
}
static int __devexit ti_ssp_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ti_ssp *ssp = dev_get_drvdata(dev);
mfd_remove_devices(dev);
clk_disable(ssp->clk);
free_irq(ssp->irq, ssp);
clk_put(ssp->clk);
iounmap(ssp->regs);
release_mem_region(ssp->res->start, resource_size(ssp->res));
kfree(ssp);
dev_set_drvdata(dev, NULL);
return 0;
}
static struct platform_driver ti_ssp_driver = {
.probe = ti_ssp_probe,
.remove = __devexit_p(ti_ssp_remove),
.driver = {
.name = "ti-ssp",
.owner = THIS_MODULE,
}
};
module_platform_driver(ti_ssp_driver);
MODULE_DESCRIPTION("Sequencer Serial Port (SSP) Driver");
MODULE_AUTHOR("Cyril Chemparathy");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ti-ssp");
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