// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * cimax2.c
 *
 * CIMax2(R) SP2 driver in conjunction with NetUp Dual DVB-S2 CI card
 *
 * Copyright (C) 2009 NetUP Inc.
 * Copyright (C) 2009 Igor M. Liplianin <liplianin@netup.ru>
 * Copyright (C) 2009 Abylay Ospan <aospan@netup.ru>
 */

#include "cx23885.h"
#include "cimax2.h"
#include <media/dvb_ca_en50221.h>

/* Max transfer size done by I2C transfer functions */
#define MAX_XFER_SIZE  64

/**** Bit definitions for MC417_RWD and MC417_OEN registers  ***
  bits 31-16
+-----------+
| Reserved  |
+-----------+
  bit 15  bit 14  bit 13 bit 12  bit 11  bit 10  bit 9   bit 8
+-------+-------+-------+-------+-------+-------+-------+-------+
|  WR#  |  RD#  |       |  ACK# |  ADHI |  ADLO |  CS1# |  CS0# |
+-------+-------+-------+-------+-------+-------+-------+-------+
 bit 7   bit 6   bit 5   bit 4   bit 3   bit 2   bit 1   bit 0
+-------+-------+-------+-------+-------+-------+-------+-------+
|  DATA7|  DATA6|  DATA5|  DATA4|  DATA3|  DATA2|  DATA1|  DATA0|
+-------+-------+-------+-------+-------+-------+-------+-------+
***/
/* MC417 */
#define NETUP_DATA              0x000000ff
#define NETUP_WR                0x00008000
#define NETUP_RD                0x00004000
#define NETUP_ACK               0x00001000
#define NETUP_ADHI              0x00000800
#define NETUP_ADLO              0x00000400
#define NETUP_CS1               0x00000200
#define NETUP_CS0               0x00000100
#define NETUP_EN_ALL            0x00001000
#define NETUP_CTRL_OFF          (NETUP_CS1 | NETUP_CS0 | NETUP_WR | NETUP_RD)
#define NETUP_CI_CTL            0x04
#define NETUP_CI_RD             1

#define NETUP_IRQ_DETAM         0x1
#define NETUP_IRQ_IRQAM         0x4

static unsigned int ci_dbg;
module_param(ci_dbg, int, 0644);
MODULE_PARM_DESC(ci_dbg, "Enable CI debugging");

static unsigned int ci_irq_enable;
module_param(ci_irq_enable, int, 0644);
MODULE_PARM_DESC(ci_irq_enable, "Enable IRQ from CAM");

#define ci_dbg_print(fmt, args...) \
        do { \
                if (ci_dbg) \
                        printk(KERN_DEBUG pr_fmt("%s: " fmt), \
                               __func__, ##args); \
        } while (0)

#define ci_irq_flags() (ci_irq_enable ? NETUP_IRQ_IRQAM : 0)

/* stores all private variables for communication with CI */
struct netup_ci_state {
        struct dvb_ca_en50221 ca;
        struct mutex ca_mutex;
        struct i2c_adapter *i2c_adap;
        u8 ci_i2c_addr;
        int status;
        struct work_struct work;
        void *priv;
        u8 current_irq_mode;
        int current_ci_flag;
        unsigned long next_status_checked_time;
};


static int netup_read_i2c(struct i2c_adapter *i2c_adap, u8 addr, u8 reg,
                                                u8 *buf, int len)
{
        int ret;
        struct i2c_msg msg[] = {
                {
                        .addr   = addr,
                        .flags  = 0,
                        .buf    = &reg,
                        .len    = 1
                }, {
                        .addr   = addr,
                        .flags  = I2C_M_RD,
                        .buf    = buf,
                        .len    = len
                }
        };

        ret = i2c_transfer(i2c_adap, msg, 2);

        if (ret != 2) {
                ci_dbg_print("%s: i2c read error, Reg = 0x%02x, Status = %d\n",
                                                __func__, reg, ret);

                return -1;
        }

        ci_dbg_print("%s: i2c read Addr=0x%04x, Reg = 0x%02x, data = %02x\n",
                                                __func__, addr, reg, buf[0]);

        return 0;
}

static int netup_write_i2c(struct i2c_adapter *i2c_adap, u8 addr, u8 reg,
                                                u8 *buf, int len)
{
        int ret;
        u8 buffer[MAX_XFER_SIZE];

        struct i2c_msg msg = {
                .addr   = addr,
                .flags  = 0,
                .buf    = &buffer[0],
                .len    = len + 1
        };

        if (1 + len > sizeof(buffer)) {
                pr_warn("%s: i2c wr reg=%04x: len=%d is too big!\n",
                       KBUILD_MODNAME, reg, len);
                return -EINVAL;
        }

        buffer[0] = reg;
        memcpy(&buffer[1], buf, len);

        ret = i2c_transfer(i2c_adap, &msg, 1);

        if (ret != 1) {
                ci_dbg_print("%s: i2c write error, Reg=[0x%02x], Status=%d\n",
                                                __func__, reg, ret);
                return -1;
        }

        return 0;
}

static int netup_ci_get_mem(struct cx23885_dev *dev)
{
        int mem;
        unsigned long timeout = jiffies + msecs_to_jiffies(1);

        for (;;) {
                mem = cx_read(MC417_RWD);
                if ((mem & NETUP_ACK) == 0)
                        break;
                if (time_after(jiffies, timeout))
                        break;
                udelay(1);
        }

        cx_set(MC417_RWD, NETUP_CTRL_OFF);

        return mem & 0xff;
}

static int netup_ci_op_cam(struct dvb_ca_en50221 *en50221, int slot,
                                u8 flag, u8 read, int addr, u8 data)
{
        struct netup_ci_state *state = en50221->data;
        struct cx23885_tsport *port = state->priv;
        struct cx23885_dev *dev = port->dev;

        u8 store;
        int mem;
        int ret;

        if (0 != slot)
                return -EINVAL;

        if (state->current_ci_flag != flag) {
                ret = netup_read_i2c(state->i2c_adap, state->ci_i2c_addr,
                                0, &store, 1);
                if (ret != 0)
                        return ret;

                store &= ~0x0c;
                store |= flag;

                ret = netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                0, &store, 1);
                if (ret != 0)
                        return ret;
        }
        state->current_ci_flag = flag;

        mutex_lock(&dev->gpio_lock);

        /* write addr */
        cx_write(MC417_OEN, NETUP_EN_ALL);
        cx_write(MC417_RWD, NETUP_CTRL_OFF |
                                NETUP_ADLO | (0xff & addr));
        cx_clear(MC417_RWD, NETUP_ADLO);
        cx_write(MC417_RWD, NETUP_CTRL_OFF |
                                NETUP_ADHI | (0xff & (addr >> 8)));
        cx_clear(MC417_RWD, NETUP_ADHI);

        if (read) { /* data in */
                cx_write(MC417_OEN, NETUP_EN_ALL | NETUP_DATA);
        } else /* data out */
                cx_write(MC417_RWD, NETUP_CTRL_OFF | data);

        /* choose chip */
        cx_clear(MC417_RWD,
                        (state->ci_i2c_addr == 0x40) ? NETUP_CS0 : NETUP_CS1);
        /* read/write */
        cx_clear(MC417_RWD, (read) ? NETUP_RD : NETUP_WR);
        mem = netup_ci_get_mem(dev);

        mutex_unlock(&dev->gpio_lock);

        if (!read)
                if (mem < 0)
                        return -EREMOTEIO;

        ci_dbg_print("%s: %s: chipaddr=[0x%x] addr=[0x%02x], %s=%x\n", __func__,
                        (read) ? "read" : "write", state->ci_i2c_addr, addr,
                        (flag == NETUP_CI_CTL) ? "ctl" : "mem",
                        (read) ? mem : data);

        if (read)
                return mem;

        return 0;
}

int netup_ci_read_attribute_mem(struct dvb_ca_en50221 *en50221,
                                                int slot, int addr)
{
        return netup_ci_op_cam(en50221, slot, 0, NETUP_CI_RD, addr, 0);
}

int netup_ci_write_attribute_mem(struct dvb_ca_en50221 *en50221,
                                                int slot, int addr, u8 data)
{
        return netup_ci_op_cam(en50221, slot, 0, 0, addr, data);
}

int netup_ci_read_cam_ctl(struct dvb_ca_en50221 *en50221, int slot,
                                 u8 addr)
{
        return netup_ci_op_cam(en50221, slot, NETUP_CI_CTL,
                                                        NETUP_CI_RD, addr, 0);
}

int netup_ci_write_cam_ctl(struct dvb_ca_en50221 *en50221, int slot,
                                                        u8 addr, u8 data)
{
        return netup_ci_op_cam(en50221, slot, NETUP_CI_CTL, 0, addr, data);
}

int netup_ci_slot_reset(struct dvb_ca_en50221 *en50221, int slot)
{
        struct netup_ci_state *state = en50221->data;
        u8 buf =  0x80;
        int ret;

        if (0 != slot)
                return -EINVAL;

        udelay(500);
        ret = netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                        0, &buf, 1);

        if (ret != 0)
                return ret;

        udelay(500);

        buf = 0x00;
        ret = netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                        0, &buf, 1);

        msleep(1000);
        dvb_ca_en50221_camready_irq(&state->ca, 0);

        return 0;

}

int netup_ci_slot_shutdown(struct dvb_ca_en50221 *en50221, int slot)
{
        /* not implemented */
        return 0;
}

static int netup_ci_set_irq(struct dvb_ca_en50221 *en50221, u8 irq_mode)
{
        struct netup_ci_state *state = en50221->data;
        int ret;

        if (irq_mode == state->current_irq_mode)
                return 0;

        ci_dbg_print("%s: chipaddr=[0x%x] setting ci IRQ to [0x%x] \n",
                        __func__, state->ci_i2c_addr, irq_mode);
        ret = netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                        0x1b, &irq_mode, 1);

        if (ret != 0)
                return ret;

        state->current_irq_mode = irq_mode;

        return 0;
}

int netup_ci_slot_ts_ctl(struct dvb_ca_en50221 *en50221, int slot)
{
        struct netup_ci_state *state = en50221->data;
        u8 buf;

        if (0 != slot)
                return -EINVAL;

        netup_read_i2c(state->i2c_adap, state->ci_i2c_addr,
                        0, &buf, 1);
        buf |= 0x60;

        return netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                        0, &buf, 1);
}

/* work handler */
static void netup_read_ci_status(struct work_struct *work)
{
        struct netup_ci_state *state =
                        container_of(work, struct netup_ci_state, work);
        u8 buf[33];
        int ret;

        /* CAM module IRQ processing. fast operation */
        dvb_ca_en50221_frda_irq(&state->ca, 0);

        /* CAM module INSERT/REMOVE processing. slow operation because of i2c
         * transfers */
        if (time_after(jiffies, state->next_status_checked_time)
                        || !state->status) {
                ret = netup_read_i2c(state->i2c_adap, state->ci_i2c_addr,
                                0, &buf[0], 33);

                state->next_status_checked_time = jiffies
                        + msecs_to_jiffies(1000);

                if (ret != 0)
                        return;

                ci_dbg_print("%s: Slot Status Addr=[0x%04x], Reg=[0x%02x], data=%02x, TS config = %02x\n",
                             __func__,  state->ci_i2c_addr, 0, buf[0], buf[0]);


                if (buf[0] & 1)
                        state->status = DVB_CA_EN50221_POLL_CAM_PRESENT |
                                DVB_CA_EN50221_POLL_CAM_READY;
                else
                        state->status = 0;
        }
}

/* CI irq handler */
int netup_ci_slot_status(struct cx23885_dev *dev, u32 pci_status)
{
        struct cx23885_tsport *port = NULL;
        struct netup_ci_state *state = NULL;

        ci_dbg_print("%s:\n", __func__);

        if (0 == (pci_status & (PCI_MSK_GPIO0 | PCI_MSK_GPIO1)))
                return 0;

        if (pci_status & PCI_MSK_GPIO0) {
                port = &dev->ts1;
                state = port->port_priv;
                schedule_work(&state->work);
                ci_dbg_print("%s: Wakeup CI0\n", __func__);
        }

        if (pci_status & PCI_MSK_GPIO1) {
                port = &dev->ts2;
                state = port->port_priv;
                schedule_work(&state->work);
                ci_dbg_print("%s: Wakeup CI1\n", __func__);
        }

        return 1;
}

int netup_poll_ci_slot_status(struct dvb_ca_en50221 *en50221,
                                     int slot, int open)
{
        struct netup_ci_state *state = en50221->data;

        if (0 != slot)
                return -EINVAL;

        netup_ci_set_irq(en50221, open ? (NETUP_IRQ_DETAM | ci_irq_flags())
                        : NETUP_IRQ_DETAM);

        return state->status;
}

int netup_ci_init(struct cx23885_tsport *port)
{
        struct netup_ci_state *state;
        u8 cimax_init[34] = {
                0x00, /* module A control*/
                0x00, /* auto select mask high A */
                0x00, /* auto select mask low A */
                0x00, /* auto select pattern high A */
                0x00, /* auto select pattern low A */
                0x44, /* memory access time A */
                0x00, /* invert input A */
                0x00, /* RFU */
                0x00, /* RFU */
                0x00, /* module B control*/
                0x00, /* auto select mask high B */
                0x00, /* auto select mask low B */
                0x00, /* auto select pattern high B */
                0x00, /* auto select pattern low B */
                0x44, /* memory access time B */
                0x00, /* invert input B */
                0x00, /* RFU */
                0x00, /* RFU */
                0x00, /* auto select mask high Ext */
                0x00, /* auto select mask low Ext */
                0x00, /* auto select pattern high Ext */
                0x00, /* auto select pattern low Ext */
                0x00, /* RFU */
                0x02, /* destination - module A */
                0x01, /* power on (use it like store place) */
                0x00, /* RFU */
                0x00, /* int status read only */
                ci_irq_flags() | NETUP_IRQ_DETAM, /* DETAM, IRQAM unmasked */
                0x05, /* EXTINT=active-high, INT=push-pull */
                0x00, /* USCG1 */
                0x04, /* ack active low */
                0x00, /* LOCK = 0 */
                0x33, /* serial mode, rising in, rising out, MSB first*/
                0x31, /* synchronization */
        };
        int ret;

        ci_dbg_print("%s\n", __func__);
        state = kzalloc_obj(struct netup_ci_state);
        if (!state) {
                ci_dbg_print("%s: Unable create CI structure!\n", __func__);
                ret = -ENOMEM;
                goto err;
        }

        port->port_priv = state;

        switch (port->nr) {
        case 1:
                state->ci_i2c_addr = 0x40;
                break;
        case 2:
                state->ci_i2c_addr = 0x41;
                break;
        }

        state->i2c_adap = &port->dev->i2c_bus[0].i2c_adap;
        state->ca.owner = THIS_MODULE;
        state->ca.read_attribute_mem = netup_ci_read_attribute_mem;
        state->ca.write_attribute_mem = netup_ci_write_attribute_mem;
        state->ca.read_cam_control = netup_ci_read_cam_ctl;
        state->ca.write_cam_control = netup_ci_write_cam_ctl;
        state->ca.slot_reset = netup_ci_slot_reset;
        state->ca.slot_shutdown = netup_ci_slot_shutdown;
        state->ca.slot_ts_enable = netup_ci_slot_ts_ctl;
        state->ca.poll_slot_status = netup_poll_ci_slot_status;
        state->ca.data = state;
        state->priv = port;
        state->current_irq_mode = ci_irq_flags() | NETUP_IRQ_DETAM;

        ret = netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                0, &cimax_init[0], 34);
        /* lock registers */
        ret |= netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                0x1f, &cimax_init[0x18], 1);
        /* power on slots */
        ret |= netup_write_i2c(state->i2c_adap, state->ci_i2c_addr,
                                                0x18, &cimax_init[0x18], 1);

        if (0 != ret)
                goto err;

        ret = dvb_ca_en50221_init(&port->frontends.adapter,
                                   &state->ca,
                                   /* flags */ 0,
                                   /* n_slots */ 1);
        if (0 != ret)
                goto err;

        INIT_WORK(&state->work, netup_read_ci_status);
        schedule_work(&state->work);

        ci_dbg_print("%s: CI initialized!\n", __func__);

        return 0;
err:
        ci_dbg_print("%s: Cannot initialize CI: Error %d.\n", __func__, ret);
        kfree(state);
        return ret;
}

void netup_ci_exit(struct cx23885_tsport *port)
{
        struct netup_ci_state *state;

        if (NULL == port)
                return;

        state = (struct netup_ci_state *)port->port_priv;
        if (NULL == state)
                return;

        if (NULL == state->ca.data)
                return;

        dvb_ca_en50221_release(&state->ca);
        kfree(state);
}