target/linux/brcm2708/patches-4.1/0136-cpufreq-bcm2835-Use-firmware-API.patch

   1 From 0daa645908304c2447c90b864d7a909f86b9e238 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
   3 Date: Mon, 20 Jul 2015 12:18:36 +0200
   4 Subject: [PATCH 136/222] cpufreq: bcm2835: Use firmware API
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Use the new firmware API instead of the legacy mailbox API.
  10
  11 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  12 ---
  13  drivers/cpufreq/bcm2835-cpufreq.c | 117 +++++++++++++++++---------------------
  14  1 file changed, 53 insertions(+), 64 deletions(-)
  15
  16 --- a/drivers/cpufreq/bcm2835-cpufreq.c
  17 +++ b/drivers/cpufreq/bcm2835-cpufreq.c
  18 @@ -26,7 +26,7 @@
  19  #include <linux/init.h>
  20  #include <linux/module.h>
  21  #include <linux/cpufreq.h>
  22 -#include <linux/platform_data/mailbox-bcm2708.h>
  23 +#include <soc/bcm2835/raspberrypi-firmware.h>
  24
  25  /* ---------- DEFINES ---------- */
  26  /*#define CPUFREQ_DEBUG_ENABLE*/               /* enable debugging */
  27 @@ -43,23 +43,6 @@
  28  #define print_err(fmt,...) pr_err("%s:%s:%d: "fmt, MODULE_NAME, __func__,__LINE__, ##__VA_ARGS__)
  29  #define print_info(fmt,...) pr_info("%s: "fmt, MODULE_NAME, ##__VA_ARGS__)
  30
  31 -/* tag part of the message */
  32 -struct vc_msg_tag {
  33 -       uint32_t tag_id;                /* the message id */
  34 -       uint32_t buffer_size;           /* size of the buffer (which in this case is always 8 bytes) */
  35 -       uint32_t data_size;             /* amount of data being sent or received */
  36 -       uint32_t dev_id;                /* the ID of the clock/voltage to get or set */
  37 -       uint32_t val;                   /* the value (e.g. rate (in Hz)) to set */
  38 -};
  39 -
  40 -/* message structure to be sent to videocore */
  41 -struct vc_msg {
  42 -       uint32_t msg_size;              /* simply, sizeof(struct vc_msg) */
  43 -       uint32_t request_code;          /* holds various information like the success and number of bytes returned (refer to mailboxes wiki) */
  44 -       struct vc_msg_tag tag;          /* the tag structure above to make */
  45 -       uint32_t end_tag;               /* an end identifier, should be set to NULL */
  46 -};
  47 -
  48  /* ---------- GLOBALS ---------- */
  49  static struct cpufreq_driver bcm2835_cpufreq_driver;   /* the cpufreq driver global */
  50
  51 @@ -74,62 +57,63 @@ static struct cpufreq_frequency_table bc
  52    clk_rate either gets or sets the clock rates.
  53   ===============================================
  54  */
  55 -static uint32_t bcm2835_cpufreq_set_clock(int cur_rate, int arm_rate)
  56 +
  57 +static int bcm2835_cpufreq_clock_property(u32 tag, u32 id, u32 *val)
  58  {
  59 -       int s, actual_rate=0;
  60 -       struct vc_msg msg;
  61 +       struct rpi_firmware *fw = rpi_firmware_get(NULL);
  62 +       struct {
  63 +               u32 id;
  64 +               u32 val;
  65 +       } packet;
  66 +       int ret;
  67 +
  68 +       packet.id = id;
  69 +       packet.val = *val;
  70 +       ret = rpi_firmware_property(fw, tag, &packet, sizeof(packet));
  71 +       if (ret)
  72 +               return ret;
  73
  74 -       /* wipe all previous message data */
  75 -       memset(&msg, 0, sizeof msg);
  76 +       *val = packet.val;
  77
  78 -       msg.msg_size = sizeof msg;
  79 +       return 0;
  80 +}
  81
  82 -       msg.tag.tag_id = VCMSG_SET_CLOCK_RATE;
  83 -       msg.tag.buffer_size = 8;
  84 -       msg.tag.data_size = 8;   /* we're sending the clock ID and the new rates which is a total of 2 words */
  85 -       msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
  86 -       msg.tag.val = arm_rate * 1000;
  87 +static uint32_t bcm2835_cpufreq_set_clock(int cur_rate, int arm_rate)
  88 +{
  89 +       u32 rate = arm_rate * 1000;
  90 +       int ret;
  91
  92 -       /* send the message */
  93 -       s = bcm_mailbox_property(&msg, sizeof msg);
  94 +       ret = bcm2835_cpufreq_clock_property(RPI_FIRMWARE_SET_CLOCK_RATE, VCMSG_ID_ARM_CLOCK, &rate);
  95 +       if (ret) {
  96 +               print_err("Failed to set clock: %d (%d)\n", arm_rate, ret);
  97 +               return 0;
  98 +       }
  99
 100 -       /* check if it was all ok and return the rate in KHz */
 101 -       if (s == 0 && (msg.request_code & 0x80000000))
 102 -               actual_rate = msg.tag.val/1000;
 103 +       rate /= 1000;
 104 +       print_debug("Setting new frequency = %d -> %d (actual %d)\n", cur_rate, arm_rate, rate);
 105
 106 -       print_debug("Setting new frequency = %d -> %d (actual %d)\n", cur_rate, arm_rate, actual_rate);
 107 -       return actual_rate;
 108 +       return rate;
 109  }
 110
 111  static uint32_t bcm2835_cpufreq_get_clock(int tag)
 112  {
 113 -       int s;
 114 -       int arm_rate = 0;
 115 -       struct vc_msg msg;
 116 -
 117 -       /* wipe all previous message data */
 118 -       memset(&msg, 0, sizeof msg);
 119 -
 120 -       msg.msg_size = sizeof msg;
 121 -       msg.tag.tag_id = tag;
 122 -       msg.tag.buffer_size = 8;
 123 -       msg.tag.data_size = 4; /* we're just sending the clock ID which is one word long */
 124 -       msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
 125 -
 126 -       /* send the message */
 127 -       s = bcm_mailbox_property(&msg, sizeof msg);
 128 -
 129 -       /* check if it was all ok and return the rate in KHz */
 130 -       if (s == 0 && (msg.request_code & 0x80000000))
 131 -               arm_rate = msg.tag.val/1000;
 132 -
 133 -       print_debug("%s frequency = %d\n",
 134 -               tag == VCMSG_GET_CLOCK_RATE ? "Current":
 135 -               tag == VCMSG_GET_MIN_CLOCK ? "Min":
 136 -               tag == VCMSG_GET_MAX_CLOCK ? "Max":
 137 -               "Unexpected", arm_rate);
 138 +       u32 rate;
 139 +       int ret;
 140 +
 141 +       ret = bcm2835_cpufreq_clock_property(tag, VCMSG_ID_ARM_CLOCK, &rate);
 142 +       if (ret) {
 143 +               print_err("Failed to get clock (%d)\n", ret);
 144 +               return 0;
 145 +       }
 146 +
 147 +       rate /= 1000;
 148 +       print_debug("%s frequency = %u\n",
 149 +               tag == RPI_FIRMWARE_GET_CLOCK_RATE ? "Current":
 150 +               tag == RPI_FIRMWARE_GET_MIN_CLOCK_RATE ? "Min":
 151 +               tag == RPI_FIRMWARE_GET_MAX_CLOCK_RATE ? "Max":
 152 +               "Unexpected", rate);
 153
 154 -       return arm_rate;
 155 +       return rate;
 156  }
 157
 158  /*
 159 @@ -165,9 +149,14 @@ static int bcm2835_cpufreq_driver_init(s
 160         /* measured value of how long it takes to change frequency */
 161         const unsigned int transition_latency = 355000; /* ns */
 162
 163 +       if (!rpi_firmware_get(NULL)) {
 164 +               print_err("Firmware is not available\n");
 165 +               return -ENODEV;
 166 +       }
 167 +
 168         /* now find out what the maximum and minimum frequencies are */
 169 -       bcm2835_freq_table[0].frequency = bcm2835_cpufreq_get_clock(VCMSG_GET_MIN_CLOCK);
 170 -       bcm2835_freq_table[1].frequency = bcm2835_cpufreq_get_clock(VCMSG_GET_MAX_CLOCK);
 171 +       bcm2835_freq_table[0].frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE);
 172 +       bcm2835_freq_table[1].frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE);
 173
 174         print_info("min=%d max=%d\n", bcm2835_freq_table[0].frequency, bcm2835_freq_table[1].frequency);
 175         return cpufreq_generic_init(policy, bcm2835_freq_table, transition_latency);
 176 @@ -201,8 +190,8 @@ static int bcm2835_cpufreq_driver_target
 177
 178  static unsigned int bcm2835_cpufreq_driver_get(unsigned int cpu)
 179  {
 180 -       unsigned int actual_rate = bcm2835_cpufreq_get_clock(VCMSG_GET_CLOCK_RATE);
 181 -       print_debug("%d: freq=%d\n", cpu, actual_rate);
 182 +       unsigned int actual_rate = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_CLOCK_RATE);
 183 +       print_debug("cpu%d: freq=%d\n", cpu, actual_rate);
 184         return actual_rate <= bcm2835_freq_table[0].frequency ? bcm2835_freq_table[0].frequency : bcm2835_freq_table[1].frequency;
 185  }
 186