target/linux/ipq806x/patches/0086-msm_serial-Add-support-for-poll_-get-put-_char.patch

   1 From 48ab619dd6e308c57dac3e5d022a3099806bf79e Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Tue, 14 Jan 2014 12:34:55 -0800
   4 Subject: [PATCH 086/182] msm_serial: Add support for poll_{get,put}_char()
   5
   6 Implement the polling functionality for the MSM serial driver.
   7 This allows us to use KGDB on this hardware.
   8
   9 Cc: David Brown <davidb@codeaurora.org>
  10 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  11 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  12 ---
  13  drivers/tty/serial/msm_serial.c |  140 ++++++++++++++++++++++++++++++++++++++-
  14  drivers/tty/serial/msm_serial.h |    9 +++
  15  2 files changed, 146 insertions(+), 3 deletions(-)
  16
  17 --- a/drivers/tty/serial/msm_serial.c
  18 +++ b/drivers/tty/serial/msm_serial.c
  19 @@ -39,6 +39,13 @@
  20
  21  #include "msm_serial.h"
  22
  23 +enum {
  24 +       UARTDM_1P1 = 1,
  25 +       UARTDM_1P2,
  26 +       UARTDM_1P3,
  27 +       UARTDM_1P4,
  28 +};
  29 +
  30  struct msm_port {
  31         struct uart_port        uart;
  32         char                    name[16];
  33 @@ -309,6 +316,8 @@ static unsigned int msm_get_mctrl(struct
  34
  35  static void msm_reset(struct uart_port *port)
  36  {
  37 +       struct msm_port *msm_port = UART_TO_MSM(port);
  38 +
  39         /* reset everything */
  40         msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
  41         msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
  42 @@ -316,6 +325,10 @@ static void msm_reset(struct uart_port *
  43         msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
  44         msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
  45         msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
  46 +
  47 +       /* Disable DM modes */
  48 +       if (msm_port->is_uartdm)
  49 +               msm_write(port, 0, UARTDM_DMEN);
  50  }
  51
  52  static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
  53 @@ -711,6 +724,117 @@ static void msm_power(struct uart_port *
  54         }
  55  }
  56
  57 +#ifdef CONFIG_CONSOLE_POLL
  58 +static int msm_poll_init(struct uart_port *port)
  59 +{
  60 +       struct msm_port *msm_port = UART_TO_MSM(port);
  61 +
  62 +       /* Enable single character mode on RX FIFO */
  63 +       if (msm_port->is_uartdm >= UARTDM_1P4)
  64 +               msm_write(port, UARTDM_DMEN_RX_SC_ENABLE, UARTDM_DMEN);
  65 +
  66 +       return 0;
  67 +}
  68 +
  69 +static int msm_poll_get_char_single(struct uart_port *port)
  70 +{
  71 +       struct msm_port *msm_port = UART_TO_MSM(port);
  72 +       unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
  73 +
  74 +       if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
  75 +               return NO_POLL_CHAR;
  76 +       else
  77 +               return msm_read(port, rf_reg) & 0xff;
  78 +}
  79 +
  80 +static int msm_poll_get_char_dm_1p3(struct uart_port *port)
  81 +{
  82 +       int c;
  83 +       static u32 slop;
  84 +       static int count;
  85 +       unsigned char *sp = (unsigned char *)&slop;
  86 +
  87 +       /* Check if a previous read had more than one char */
  88 +       if (count) {
  89 +               c = sp[sizeof(slop) - count];
  90 +               count--;
  91 +       /* Or if FIFO is empty */
  92 +       } else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
  93 +               /*
  94 +                * If RX packing buffer has less than a word, force stale to
  95 +                * push contents into RX FIFO
  96 +                */
  97 +               count = msm_read(port, UARTDM_RXFS);
  98 +               count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
  99 +               if (count) {
 100 +                       msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
 101 +                       slop = msm_read(port, UARTDM_RF);
 102 +                       c = sp[0];
 103 +                       count--;
 104 +               } else {
 105 +                       c = NO_POLL_CHAR;
 106 +               }
 107 +       /* FIFO has a word */
 108 +       } else {
 109 +               slop = msm_read(port, UARTDM_RF);
 110 +               c = sp[0];
 111 +               count = sizeof(slop) - 1;
 112 +       }
 113 +
 114 +       return c;
 115 +}
 116 +
 117 +static int msm_poll_get_char(struct uart_port *port)
 118 +{
 119 +       u32 imr;
 120 +       int c;
 121 +       struct msm_port *msm_port = UART_TO_MSM(port);
 122 +
 123 +       /* Disable all interrupts */
 124 +       imr = msm_read(port, UART_IMR);
 125 +       msm_write(port, 0, UART_IMR);
 126 +
 127 +       if (msm_port->is_uartdm == UARTDM_1P3)
 128 +               c = msm_poll_get_char_dm_1p3(port);
 129 +       else
 130 +               c = msm_poll_get_char_single(port);
 131 +
 132 +       /* Enable interrupts */
 133 +       msm_write(port, imr, UART_IMR);
 134 +
 135 +       return c;
 136 +}
 137 +
 138 +static void msm_poll_put_char(struct uart_port *port, unsigned char c)
 139 +{
 140 +       u32 imr;
 141 +       struct msm_port *msm_port = UART_TO_MSM(port);
 142 +
 143 +       /* Disable all interrupts */
 144 +       imr = msm_read(port, UART_IMR);
 145 +       msm_write(port, 0, UART_IMR);
 146 +
 147 +       if (msm_port->is_uartdm)
 148 +               reset_dm_count(port, 1);
 149 +
 150 +       /* Wait until FIFO is empty */
 151 +       while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 152 +               cpu_relax();
 153 +
 154 +       /* Write a character */
 155 +       msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
 156 +
 157 +       /* Wait until FIFO is empty */
 158 +       while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
 159 +               cpu_relax();
 160 +
 161 +       /* Enable interrupts */
 162 +       msm_write(port, imr, UART_IMR);
 163 +
 164 +       return;
 165 +}
 166 +#endif
 167 +
 168  static struct uart_ops msm_uart_pops = {
 169         .tx_empty = msm_tx_empty,
 170         .set_mctrl = msm_set_mctrl,
 171 @@ -729,6 +853,11 @@ static struct uart_ops msm_uart_pops = {
 172         .config_port = msm_config_port,
 173         .verify_port = msm_verify_port,
 174         .pm = msm_power,
 175 +#ifdef CONFIG_CONSOLE_POLL
 176 +       .poll_init = msm_poll_init,
 177 +       .poll_get_char  = msm_poll_get_char,
 178 +       .poll_put_char  = msm_poll_put_char,
 179 +#endif
 180  };
 181
 182  static struct msm_port msm_uart_ports[] = {
 183 @@ -900,7 +1029,10 @@ static struct uart_driver msm_uart_drive
 184  static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
 185
 186  static const struct of_device_id msm_uartdm_table[] = {
 187 -       { .compatible = "qcom,msm-uartdm" },
 188 +       { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
 189 +       { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
 190 +       { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
 191 +       { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
 192         { }
 193  };
 194
 195 @@ -909,6 +1041,7 @@ static int __init msm_serial_probe(struc
 196         struct msm_port *msm_port;
 197         struct resource *resource;
 198         struct uart_port *port;
 199 +       const struct of_device_id *id;
 200         int irq;
 201
 202         if (pdev->id == -1)
 203 @@ -923,8 +1056,9 @@ static int __init msm_serial_probe(struc
 204         port->dev = &pdev->dev;
 205         msm_port = UART_TO_MSM(port);
 206
 207 -       if (of_match_device(msm_uartdm_table, &pdev->dev))
 208 -               msm_port->is_uartdm = 1;
 209 +       id = of_match_device(msm_uartdm_table, &pdev->dev);
 210 +       if (id)
 211 +               msm_port->is_uartdm = (unsigned long)id->data;
 212         else
 213                 msm_port->is_uartdm = 0;
 214
 215 --- a/drivers/tty/serial/msm_serial.h
 216 +++ b/drivers/tty/serial/msm_serial.h
 217 @@ -59,6 +59,7 @@
 218  #define UART_CR_CMD_RESET_RFR          (14 << 4)
 219  #define UART_CR_CMD_PROTECTION_EN      (16 << 4)
 220  #define UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4)
 221 +#define UART_CR_CMD_FORCE_STALE                (4 << 8)
 222  #define UART_CR_CMD_RESET_TX_READY     (3 << 8)
 223  #define UART_CR_TX_DISABLE             (1 << 3)
 224  #define UART_CR_TX_ENABLE              (1 << 2)
 225 @@ -113,6 +114,14 @@
 226  #define GSBI_PROTOCOL_UART     0x40
 227  #define GSBI_PROTOCOL_IDLE     0x0
 228
 229 +#define UARTDM_RXFS            0x50
 230 +#define UARTDM_RXFS_BUF_SHIFT  0x7
 231 +#define UARTDM_RXFS_BUF_MASK   0x7
 232 +
 233 +#define UARTDM_DMEN            0x3C
 234 +#define UARTDM_DMEN_RX_SC_ENABLE BIT(5)
 235 +#define UARTDM_DMEN_TX_SC_ENABLE BIT(4)
 236 +
 237  #define UARTDM_DMRX            0x34
 238  #define UARTDM_NCF_TX          0x40
 239  #define UARTDM_RX_TOTAL_SNAP   0x38