more non-working serial stuff

[ms2-kexec] / board-mapphone-emu_uart.c

/*
 * board-mapphone-emu_uart.c
 *
 * Copyright (C) 2009 Motorola, 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
 */

/* Date         Author          Comment
 * ===========  ==============  ==============================================
 * Jun-26-2009  Motorola        Initial revision.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <linux/spi/spi.h>
#include <plat/system.h>
#include <linux/irq.h>

#include <plat/dma.h>
#include <plat/clock.h>
#include <plat/board-mapphone-emu_uart.h>
#include <plat/hardware.h>
#include <plat/omap34xx.h>

/*
 * Register definitions for CPCAP related SPI register
 */
#define OMAP2_MCSPI_MAX_FREQ            48000000

#define OMAP2_MCSPI_REVISION            0x00
#define OMAP2_MCSPI_SYSCONFIG           0x10
#define OMAP2_MCSPI_SYSSTATUS           0x14
#define OMAP2_MCSPI_IRQSTATUS           0x18
#define OMAP2_MCSPI_IRQENABLE           0x1c
#define OMAP2_MCSPI_WAKEUPENABLE        0x20
#define OMAP2_MCSPI_SYST                0x24
#define OMAP2_MCSPI_MODULCTRL           0x28

/* per-channel banks, 0x14 bytes each, first is: */
#define OMAP2_MCSPI_CHCONF0             0x2c
#define OMAP2_MCSPI_CHSTAT0             0x30
#define OMAP2_MCSPI_CHCTRL0             0x34
#define OMAP2_MCSPI_TX0                 0x38
#define OMAP2_MCSPI_RX0                 0x3c

/* per-register bitmasks: */

#define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE  (1 << 0)
#define OMAP2_MCSPI_SYSCONFIG_SOFTRESET (1 << 1)
#define OMAP2_AFTR_RST_SET_MASTER       (0 << 2)

#define OMAP2_MCSPI_SYSSTATUS_RESETDONE (1 << 0)
#define OMAP2_MCSPI_SYS_CON_LVL_1 1
#define OMAP2_MCSPI_SYS_CON_LVL_2 2

#define OMAP2_MCSPI_MODULCTRL_SINGLE    (1 << 0)
#define OMAP2_MCSPI_MODULCTRL_MS        (1 << 2)
#define OMAP2_MCSPI_MODULCTRL_STEST     (1 << 3)

#define OMAP2_MCSPI_CHCONF_PHA          (1 << 0)
#define OMAP2_MCSPI_CHCONF_POL          (1 << 1)
#define OMAP2_MCSPI_CHCONF_CLKD_MASK    (0x0f << 2)
#define OMAP2_MCSPI_CHCONF_EPOL         (1 << 6)
#define OMAP2_MCSPI_CHCONF_WL_MASK      (0x1f << 7)
#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY  (0x01 << 12)
#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY  (0x02 << 12)
#define OMAP2_MCSPI_CHCONF_TRM_MASK     (0x03 << 12)
#define OMAP2_MCSPI_CHCONF_TRM_TXRX     (~OMAP2_MCSPI_CHCONF_TRM_MASK)
#define OMAP2_MCSPI_CHCONF_DMAW         (1 << 14)
#define OMAP2_MCSPI_CHCONF_DMAR         (1 << 15)
#define OMAP2_MCSPI_CHCONF_DPE0         (1 << 16)
#define OMAP2_MCSPI_CHCONF_DPE1         (1 << 17)
#define OMAP2_MCSPI_CHCONF_IS           (1 << 18)
#define OMAP2_MCSPI_CHCONF_TURBO        (1 << 19)
#define OMAP2_MCSPI_CHCONF_FORCE        (1 << 20)
#define OMAP2_MCSPI_CHCONF_TCS0         (1 << 25)
#define OMAP2_MCSPI_CHCONF_TCS1         (1 << 26)
#define OMAP2_MCSPI_CHCONF_TCS_MASK     (0x03 << 25)

#define OMAP2_MCSPI_SYSCFG_WKUP         (1 << 2)
#define OMAP2_MCSPI_SYSCFG_IDL          (2 << 3)
#define OMAP2_MCSPI_SYSCFG_CLK          (2 << 8)
#define OMAP2_MCSPI_WAKEUP_EN           (1 << 1)
#define OMAP2_MCSPI_IRQ_WKS             (1 << 16)
#define OMAP2_MCSPI_CHSTAT_RXS          (1 << 0)
#define OMAP2_MCSPI_CHSTAT_TXS          (1 << 1)
#define OMAP2_MCSPI_CHSTAT_EOT          (1 << 2)

#define OMAP2_MCSPI_CHCTRL_EN           (1 << 0)
#define OMAP2_MCSPI_MODE_IS_MASTER      0
#define OMAP2_MCSPI_MODE_IS_SLAVE       1
#define OMAP_MCSPI_WAKEUP_ENABLE        1

/*mcspi base address: (0x48098000)1st SPI, (0x4809A00) 2nd SPI*/
#define OMAP_MCSPI_BASE 0x48098000

#define WORD_LEN            32
#define CLOCK_DIV           12  /* 2^(12)=4096  48000000/4096<19200 */

#define LEVEL1              1
#define LEVEL2              2
#define WRITE_CPCAP         1
#define READ_CPCAP          0

#define CM_ICLKEN1_CORE  0x48004A10
#define CM_FCLKEN1_CORE  0x48004A00
#define OMAP2_MCSPI_EN_MCSPI1   (1 << 18)

#define  RESET_FAIL      1
#define RAW_MOD_REG_BIT(val, mask, set) do { \
    if (set) \
                val |= mask; \
    else \
                 val &= ~mask; \
} while (0)

struct cpcap_dev {
        u16 address;
        u16 value;
        u32 result;
        int access_flag;
};

static char tx[4];
static bool emu_uart_is_active = FALSE;

/*   Although SPI driver is provided through linux system as implemented above,
 *   it can not cover some special situation.
 *
 *   During Debug phase, OMAP may need to acess CPCAP by SPI
 *   to configure or check related register when boot up is not finished.
 *   However, at this time, spi driver integrated in linux system may not
 *   be initialized properly.
 *
 *   So we provode the following SPI driver with common API for access capcap
 *   by SPI directly, i.e. we will skip the linux system driver,
 *   but access SPI hardware directly to configure read/write specially for
 *   cpcap access.
 *
 *   So developer should be very careful to use these APIs:
 *
 *        read_cpcap_register_raw()
 *        write_cpcap_register_raw()
 *
 *   Pay attention: Only use them when boot up phase.
 *   Rasons are as follows:
 *   1. Although we provide protection on these two APIs for concurrency and
 *      race conditions, it may impact the performance of system
 *      because it will mask all interrupts during access.
 *   2. Calling these APIs will reset all SPI registers, and may make previous
 *      data lost during run time.
 *
 *      So, if developer wants to access CPCAP after boot up is finished,
 *      we suggest they should use poweric interface.
 *
 */
static inline void raw_writel_reg(u32 value, u32 reg)
{
        unsigned int absolute_reg = (u32)OMAP_MCSPI_BASE + reg;
#if defined(LOCAL_DEVELOPER_DEBUG)
        printk(KERN_ERR " raw write reg =0x%x value=0x%x \n", absolute_reg,
               value);
#endif
        omap_writel(value, absolute_reg);
}

static inline u32 raw_readl_reg(u32 reg)
{
        u32 result;
        unsigned int absolute_reg = (u32)OMAP_MCSPI_BASE + reg;
        result = omap_readl(absolute_reg);
#if defined(LOCAL_DEVELOPER_DEBUG)
        printk(KERN_ERR " raw read reg =0x%x result =0x%x  \n",
               absolute_reg, result);
#endif
        return result;
}

static void raw_omap_mcspi_wakeup_enable(int level)
{
        u32 result;

        /* configure SYSCONFIG register...  */
        if (level == LEVEL1) {
                result = raw_readl_reg(OMAP2_MCSPI_SYSCONFIG);
                result =
                    result | OMAP2_MCSPI_SYSCFG_WKUP |
                    OMAP2_MCSPI_SYSCFG_IDL | OMAP2_MCSPI_SYSCFG_CLK |
                    OMAP2_MCSPI_SYSCONFIG_AUTOIDLE;
                raw_writel_reg(result, OMAP2_MCSPI_SYSCONFIG);
        }

        if (level == LEVEL2) {
                result = raw_readl_reg(OMAP2_MCSPI_SYSCONFIG);
                result =
                    result | OMAP2_MCSPI_SYSCFG_WKUP |
                    OMAP2_MCSPI_SYSCFG_IDL |
                    OMAP2_MCSPI_SYSCONFIG_AUTOIDLE;
                RAW_MOD_REG_BIT(result, OMAP2_MCSPI_SYSCFG_CLK, 0);
                raw_writel_reg(result, OMAP2_MCSPI_SYSCONFIG);
        }

        /* configure wakeupenable register...  */
        raw_writel_reg(OMAP2_MCSPI_WAKEUP_EN, OMAP2_MCSPI_WAKEUPENABLE);

        /* configure enable interrupt register... */
        result = raw_readl_reg(OMAP2_MCSPI_IRQENABLE);
        result = result | OMAP2_MCSPI_IRQ_WKS;
        raw_writel_reg(result, OMAP2_MCSPI_IRQENABLE);
}

static void raw_omap2_mcspi_set_master_mode(void)
{
        u32 result;

        /* configure MCSPI_MODULCTRL register... */
        result = raw_readl_reg(OMAP2_MCSPI_MODULCTRL);

        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_MODULCTRL_STEST, 0);
        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_MODULCTRL_MS,
                        OMAP2_MCSPI_MODE_IS_MASTER);
        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);

        raw_writel_reg(result, OMAP2_MCSPI_MODULCTRL);
}

static void raw_omap2_mcspi_channel_config(void)
{
        u32 result;

        /* select channel 0... otherwise 0x14*channel_num */
        result = raw_readl_reg(OMAP2_MCSPI_CHCONF0);

        /* TCS Chip select Timing(2.5 clock cycles) */
        result &= ~(OMAP2_MCSPI_CHCONF_TCS_MASK);
        result |= OMAP2_MCSPI_CHCONF_TCS1;

        /* configure master mode... */
        result &= ~OMAP2_MCSPI_CHCONF_IS;
        result &= ~OMAP2_MCSPI_CHCONF_DPE1;
        result |= OMAP2_MCSPI_CHCONF_DPE0;

        /* configure wordlength  */
        result &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
        result |= (WORD_LEN - 1) << 7;

        /*  configure active high  */
        result &= ~OMAP2_MCSPI_CHCONF_EPOL;

        /* set clock divisor  */
        result &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
        result |= CLOCK_DIV << 2;

        /* configure mode  polarity=0 phase=0  */
        result &= ~OMAP2_MCSPI_CHCONF_POL;
        result &= ~OMAP2_MCSPI_CHCONF_PHA;

        raw_writel_reg(result, OMAP2_MCSPI_CHCONF0);

}

static void raw_mcspi_setup(void)
{
        raw_omap_mcspi_wakeup_enable(LEVEL1);
        raw_omap2_mcspi_set_master_mode();
        raw_omap2_mcspi_channel_config();
        raw_omap_mcspi_wakeup_enable(LEVEL2);
}

static int raw_mcspi_reset(void)
{
        unsigned long timeout;
        u32 tmp;

        raw_omap_mcspi_wakeup_enable(LEVEL1);

        raw_writel_reg(OMAP2_MCSPI_SYSCONFIG_SOFTRESET,
                      OMAP2_MCSPI_SYSCONFIG);

        timeout = jiffies + msecs_to_jiffies(1000);

        do {
                tmp = raw_readl_reg(OMAP2_MCSPI_SYSSTATUS);
                if (time_after(jiffies, timeout)) {
                        printk(KERN_ERR "SPI Error: Reset is time out!\n");
                        return -RESET_FAIL;
                }
        } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));

        /*configure all modules in  reset master mode */
        raw_writel_reg(OMAP2_AFTR_RST_SET_MASTER, OMAP2_MCSPI_MODULCTRL);

        /* call wakeup function to set sysconfig as per pm activity */
        raw_omap_mcspi_wakeup_enable(LEVEL1);
        raw_omap_mcspi_wakeup_enable(LEVEL2);

        return 0;
}

static void raw_omap2_mcspi_force_cs(int enable_tag)
{
        u32 result;
        result = raw_readl_reg(OMAP2_MCSPI_CHCONF0);
        /*
         * Manual spim_csx assertion to keep spim_csx for channel x active
         * RW 0x0 between SPI words (single channel master mode only).
         */
        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_CHCONF_FORCE, enable_tag);
        raw_writel_reg(result, OMAP2_MCSPI_CHCONF0);
}

static void raw_omap2_mcspi_set_enable(int enable)
{
        u32 result;

        result = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
        raw_writel_reg(result, OMAP2_MCSPI_CHCTRL0);
}


static int raw_mcspi_wait_for_reg_bit(unsigned long reg, unsigned long bit)
{
        unsigned long timeout;

        timeout = jiffies + msecs_to_jiffies(1000);

        while (!(raw_readl_reg(reg) & bit)) {
                if (time_after(jiffies, timeout))
                        return -1;
        }

        return 0;
}

static void parser_cpcap(struct cpcap_dev *dev)
{
        if (dev->access_flag == WRITE_CPCAP) {
                tx[3] = ((dev->address >> 6) & 0x000000FF) | 0x80;
                tx[2] = (dev->address << 2) & 0x000000FF;
                tx[1] = (dev->value >> 8) & 0x000000FF;
                tx[0] = dev->value & 0x000000FF;
        } else {
                tx[3] = ((dev->address >> 6) & 0x000000FF);
                tx[2] = (dev->address << 2) & 0x000000FF;
                tx[1] = 1;
                tx[0] = 1;
        }
}

static void raw_omap2_mcspi_txrx_pio(struct cpcap_dev *dev)
{
        u32 result;
        u32 tx_32bit;

        /* config tranmission mode --- tx rx together */
        result = raw_readl_reg(OMAP2_MCSPI_CHCONF0);
        result &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
        raw_writel_reg(result, OMAP2_MCSPI_CHCONF0);

        /* enable the mcspi port! */
        raw_omap2_mcspi_set_enable(1);

        parser_cpcap(dev);

        memcpy((void *)&tx_32bit, (void *)tx, 4);

        if (raw_mcspi_wait_for_reg_bit(OMAP2_MCSPI_CHSTAT0,
                                       OMAP2_MCSPI_CHSTAT_TXS) < 0) {
                printk(KERN_ERR "SPI Error: TXS timed out\n");
                goto out;
        }
        raw_writel_reg(tx_32bit, OMAP2_MCSPI_TX0);

        if (raw_mcspi_wait_for_reg_bit(OMAP2_MCSPI_CHSTAT0,
                                       OMAP2_MCSPI_CHSTAT_RXS) < 0) {
                printk(KERN_ERR "SPI Error: RXS timed out\n");
                goto out;
        }

        result = raw_readl_reg(OMAP2_MCSPI_RX0);

        dev->result = result;

out:
        /* disable the mcspi port! */
        raw_omap2_mcspi_set_enable(0);
}

static void raw_mcspi_run(struct cpcap_dev *dev)
{
        raw_omap_mcspi_wakeup_enable(LEVEL1);
        raw_omap2_mcspi_set_master_mode();
        raw_omap2_mcspi_channel_config();
        raw_omap2_mcspi_force_cs(1);
        raw_omap2_mcspi_txrx_pio(dev);
        raw_omap2_mcspi_force_cs(0);
        raw_omap_mcspi_wakeup_enable(LEVEL2);
}

static void raw_omap_mcspi_enable_IFclock(void)
{
        u32 result;

        result = omap_readl(CM_FCLKEN1_CORE);
        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_EN_MCSPI1, 1);
        omap_writel(result, CM_FCLKEN1_CORE);

        result = omap_readl(CM_ICLKEN1_CORE);
        RAW_MOD_REG_BIT(result, OMAP2_MCSPI_EN_MCSPI1, 1);
        omap_writel(result, CM_ICLKEN1_CORE);

}

/*
 * write_cpcap_register_raw is for cpcap spi write directly
 * @return 0 on success; less than zero on failure.
 */
static int write_cpcap_register_raw(u16 addr, u16 val)
{
        int result;
        unsigned long intr_flags;
        struct cpcap_dev cpcap_write;

#ifdef CONFIG_EMU_UART_DEBUG
        if (is_emu_uart_active() && (addr == 897 || addr == 411))
                return 0;
#endif

        local_irq_save(intr_flags);
        raw_omap_mcspi_enable_IFclock();

        result = raw_mcspi_reset();
        if (result < 0) {
                local_irq_restore(intr_flags);
                printk(KERN_ERR "reset failed !\n");
                return result;
        }

        raw_mcspi_setup();

        cpcap_write.address = addr;
        cpcap_write.value = val;
        cpcap_write.access_flag = WRITE_CPCAP;
        raw_mcspi_run(&cpcap_write);

        local_irq_restore(intr_flags);

        return result;
}

/*
 *  read_cpcap_register_raw is for cpcap spi read directly,
 *  read result is in val
 *  @return 0 on success; less than zero on failure.
 */
static int read_cpcap_register_raw(u16 addr, u16 *val)
{
        int result;
        unsigned long intr_flag;
        struct cpcap_dev cpcap_read;

        local_irq_save(intr_flag);
        raw_omap_mcspi_enable_IFclock();

        result = raw_mcspi_reset();
        if (result < 0) {
                local_irq_restore(intr_flag);
                printk(KERN_ERR "reset failed !\n");
                return result;
        }

        raw_mcspi_setup();

        cpcap_read.address = addr;
        cpcap_read.access_flag = READ_CPCAP;
        raw_mcspi_run(&cpcap_read);
        *val = cpcap_read.result;

        local_irq_restore(intr_flag);

        return result;
}

/*
 * Check if the writting is allowed. If MiniUSB port has already been
 * configured as UART3, we should ignore some SCM register writting.
 */
int is_emu_uart_iomux_reg(unsigned short offset)
{
        if ((emu_uart_is_active) && \
            ((offset >= 0x1A2 && offset < 0x1BA) || (offset == 0x19E)))
                return 1;
        else
                return 0;
}

bool is_emu_uart_active(void)
{
        return emu_uart_is_active;
}

static void write_omap_mux_register(u16 offset, u8 mode, u8 input_en)
{
        u16 tmp_val, reg_val;
        u32 reg = OMAP343X_CTRL_BASE + offset;

        reg_val = mode | (input_en << 8);
        tmp_val = omap_readw(reg) & ~(0x0007 | (1 << 8));
        reg_val = reg_val | tmp_val;
        omap_writew(reg_val, reg);
}

void activate_emu_uart(void)
{
        int i;
        u16 tmp = 0;

        read_cpcap_register_raw(18, &tmp);
        printk(KERN_ALERT "Reading CPCAP vendor_version: 0x%04X\n", tmp);
        /*
         * Step 1:
         * Configure OMAP SCM to set all ULPI pin of USB OTG to SAFE MODE
         */
        for (i = 0; i < 0x18; i += 2)
                write_omap_mux_register(0x1A2 + i, 7, 0);

        /*
         * Step 2:
         * Configure CPCAP to route UART3 to USB port; Switch VBUSIN to supply
         * UART/USB transeiver and set VBUS standby mode 3
         */
        write_cpcap_register_raw(897, 0x0101);
        write_cpcap_register_raw(411, 0x014C);

        /* Step 3:
         * Configure OMAP SCM to set ULPI port as UART3 function
         */
        /*
         * Set UART3 RX pin in safe mode
         */
        write_omap_mux_register(0x19E, 7, 0);
        /*
         * Route UART3 TX to ULPIDATA0, RX to ULPIDATA1
         */
        write_omap_mux_register(0x1AA, 2, 0);
        write_omap_mux_register(0x1AC, 2, 1);

        emu_uart_is_active = TRUE;
        printk
            (KERN_ALERT "WARNING: MiniUSB port works in UART3 mode,"
             "the USB functionality UNAVAILABLE!\n");

}