diff options
Diffstat (limited to 'arch/arm/mach-ux500/prcmu.c')
| -rw-r--r-- | arch/arm/mach-ux500/prcmu.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/prcmu.c b/arch/arm/mach-ux500/prcmu.c new file mode 100644 index 000000000000..293274d1342a --- /dev/null +++ b/arch/arm/mach-ux500/prcmu.c @@ -0,0 +1,231 @@ +/* + * Copyright (C) ST Ericsson SA 2010 + * + * License Terms: GNU General Public License v2 + * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> + * + * U8500 PRCMU driver. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/mutex.h> +#include <linux/completion.h> +#include <linux/jiffies.h> +#include <linux/bitops.h> +#include <linux/interrupt.h> + +#include <mach/hardware.h> +#include <mach/prcmu-regs.h> + +#define PRCMU_TCDM_BASE __io_address(U8500_PRCMU_TCDM_BASE) + +#define REQ_MB5 (PRCMU_TCDM_BASE + 0xE44) +#define ACK_MB5 (PRCMU_TCDM_BASE + 0xDF4) + +#define REQ_MB5_I2C_SLAVE_OP (REQ_MB5) +#define REQ_MB5_I2C_HW_BITS (REQ_MB5 + 1) +#define REQ_MB5_I2C_REG (REQ_MB5 + 2) +#define REQ_MB5_I2C_VAL (REQ_MB5 + 3) + +#define ACK_MB5_I2C_STATUS (ACK_MB5 + 1) +#define ACK_MB5_I2C_VAL (ACK_MB5 + 3) + +#define I2C_WRITE(slave) ((slave) << 1) +#define I2C_READ(slave) (((slave) << 1) | BIT(0)) +#define I2C_STOP_EN BIT(3) + +enum ack_mb5_status { + I2C_WR_OK = 0x01, + I2C_RD_OK = 0x02, +}; + +#define MBOX_BIT BIT +#define NUM_MBOX 8 + +static struct { + struct mutex lock; + struct completion work; + bool failed; + struct { + u8 status; + u8 value; + } ack; +} mb5_transfer; + +/** + * prcmu_abb_read() - Read register value(s) from the ABB. + * @slave: The I2C slave address. + * @reg: The (start) register address. + * @value: The read out value(s). + * @size: The number of registers to read. + * + * Reads register value(s) from the ABB. + * @size has to be 1 for the current firmware version. + */ +int prcmu_abb_read(u8 slave, u8 reg, u8 *value, u8 size) +{ + int r; + + if (size != 1) + return -EINVAL; + + r = mutex_lock_interruptible(&mb5_transfer.lock); + if (r) + return r; + + while (readl(PRCM_MBOX_CPU_VAL) & MBOX_BIT(5)) + cpu_relax(); + + writeb(I2C_READ(slave), REQ_MB5_I2C_SLAVE_OP); + writeb(I2C_STOP_EN, REQ_MB5_I2C_HW_BITS); + writeb(reg, REQ_MB5_I2C_REG); + + writel(MBOX_BIT(5), PRCM_MBOX_CPU_SET); + if (!wait_for_completion_timeout(&mb5_transfer.work, + msecs_to_jiffies(500))) { + pr_err("prcmu: prcmu_abb_read timed out.\n"); + r = -EIO; + goto unlock_and_return; + } + r = ((mb5_transfer.ack.status == I2C_RD_OK) ? 0 : -EIO); + if (!r) + *value = mb5_transfer.ack.value; + +unlock_and_return: + mutex_unlock(&mb5_transfer.lock); + return r; +} +EXPORT_SYMBOL(prcmu_abb_read); + +/** + * prcmu_abb_write() - Write register value(s) to the ABB. + * @slave: The I2C slave address. + * @reg: The (start) register address. + * @value: The value(s) to write. + * @size: The number of registers to write. + * + * Reads register value(s) from the ABB. + * @size has to be 1 for the current firmware version. + */ +int prcmu_abb_write(u8 slave, u8 reg, u8 *value, u8 size) +{ + int r; + + if (size != 1) + return -EINVAL; + + r = mutex_lock_interruptible(&mb5_transfer.lock); + if (r) + return r; + + + while (readl(PRCM_MBOX_CPU_VAL) & MBOX_BIT(5)) + cpu_relax(); + + writeb(I2C_WRITE(slave), REQ_MB5_I2C_SLAVE_OP); + writeb(I2C_STOP_EN, REQ_MB5_I2C_HW_BITS); + writeb(reg, REQ_MB5_I2C_REG); + writeb(*value, REQ_MB5_I2C_VAL); + + writel(MBOX_BIT(5), PRCM_MBOX_CPU_SET); + if (!wait_for_completion_timeout(&mb5_transfer.work, + msecs_to_jiffies(500))) { + pr_err("prcmu: prcmu_abb_write timed out.\n"); + r = -EIO; + goto unlock_and_return; + } + r = ((mb5_transfer.ack.status == I2C_WR_OK) ? 0 : -EIO); + +unlock_and_return: + mutex_unlock(&mb5_transfer.lock); + return r; +} +EXPORT_SYMBOL(prcmu_abb_write); + +static void read_mailbox_0(void) +{ + writel(MBOX_BIT(0), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_1(void) +{ + writel(MBOX_BIT(1), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_2(void) +{ + writel(MBOX_BIT(2), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_3(void) +{ + writel(MBOX_BIT(3), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_4(void) +{ + writel(MBOX_BIT(4), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_5(void) +{ + mb5_transfer.ack.status = readb(ACK_MB5_I2C_STATUS); + mb5_transfer.ack.value = readb(ACK_MB5_I2C_VAL); + complete(&mb5_transfer.work); + writel(MBOX_BIT(5), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_6(void) +{ + writel(MBOX_BIT(6), PRCM_ARM_IT1_CLEAR); +} + +static void read_mailbox_7(void) +{ + writel(MBOX_BIT(7), PRCM_ARM_IT1_CLEAR); +} + +static void (* const read_mailbox[NUM_MBOX])(void) = { + read_mailbox_0, + read_mailbox_1, + read_mailbox_2, + read_mailbox_3, + read_mailbox_4, + read_mailbox_5, + read_mailbox_6, + read_mailbox_7 +}; + +static irqreturn_t prcmu_irq_handler(int irq, void *data) +{ + u32 bits; + u8 n; + + bits = (readl(PRCM_ARM_IT1_VAL) & (MBOX_BIT(NUM_MBOX) - 1)); + if (unlikely(!bits)) + return IRQ_NONE; + + for (n = 0; bits; n++) { + if (bits & MBOX_BIT(n)) { + bits -= MBOX_BIT(n); + read_mailbox[n](); + } + } + return IRQ_HANDLED; +} + +static int __init prcmu_init(void) +{ + mutex_init(&mb5_transfer.lock); + init_completion(&mb5_transfer.work); + + /* Clean up the mailbox interrupts after pre-kernel code. */ + writel((MBOX_BIT(NUM_MBOX) - 1), PRCM_ARM_IT1_CLEAR); + + return request_irq(IRQ_PRCMU, prcmu_irq_handler, 0, "prcmu", NULL); +} + +arch_initcall(prcmu_init); |