marcus chiou
mbed library sources
Fork of
mbed-src
by 
mbed official
targets/hal/TARGET_Atmel/TARGET_SAM21/drivers/system/clock/clock_samd21_r21/gclk.c@579:53297373a894, 2015-07-01 (annotated)
- Committer:
- mbed_official
- Date:
- Wed Jul 01 09:45:11 2015 +0100
- Revision:
- 579:53297373a894
- Child:
- 592:a274ee790e56
Synchronized with git revision d5b4d2ab9c47edb4dc5776e7177b0c2263459081
Full URL: https://github.com/mbedmicro/mbed/commit/d5b4d2ab9c47edb4dc5776e7177b0c2263459081/
Initial version of drivers for SAMR21
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| mbed_official | 579:53297373a894 | 1 | /** |
| mbed_official | 579:53297373a894 | 2 | * \file |
| mbed_official | 579:53297373a894 | 3 | * |
| mbed_official | 579:53297373a894 | 4 | * \brief SAM D21/R21 Generic Clock Driver |
| mbed_official | 579:53297373a894 | 5 | * |
| mbed_official | 579:53297373a894 | 6 | * Copyright (C) 2013-2014 Atmel Corporation. All rights reserved. |
| mbed_official | 579:53297373a894 | 7 | * |
| mbed_official | 579:53297373a894 | 8 | * \asf_license_start |
| mbed_official | 579:53297373a894 | 9 | * |
| mbed_official | 579:53297373a894 | 10 | * \page License |
| mbed_official | 579:53297373a894 | 11 | * |
| mbed_official | 579:53297373a894 | 12 | * Redistribution and use in source and binary forms, with or without |
| mbed_official | 579:53297373a894 | 13 | * modification, are permitted provided that the following conditions are met: |
| mbed_official | 579:53297373a894 | 14 | * |
| mbed_official | 579:53297373a894 | 15 | * 1. Redistributions of source code must retain the above copyright notice, |
| mbed_official | 579:53297373a894 | 16 | * this list of conditions and the following disclaimer. |
| mbed_official | 579:53297373a894 | 17 | * |
| mbed_official | 579:53297373a894 | 18 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| mbed_official | 579:53297373a894 | 19 | * this list of conditions and the following disclaimer in the documentation |
| mbed_official | 579:53297373a894 | 20 | * and/or other materials provided with the distribution. |
| mbed_official | 579:53297373a894 | 21 | * |
| mbed_official | 579:53297373a894 | 22 | * 3. The name of Atmel may not be used to endorse or promote products derived |
| mbed_official | 579:53297373a894 | 23 | * from this software without specific prior written permission. |
| mbed_official | 579:53297373a894 | 24 | * |
| mbed_official | 579:53297373a894 | 25 | * 4. This software may only be redistributed and used in connection with an |
| mbed_official | 579:53297373a894 | 26 | * Atmel microcontroller product. |
| mbed_official | 579:53297373a894 | 27 | * |
| mbed_official | 579:53297373a894 | 28 | * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED |
| mbed_official | 579:53297373a894 | 29 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| mbed_official | 579:53297373a894 | 30 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE |
| mbed_official | 579:53297373a894 | 31 | * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR |
| mbed_official | 579:53297373a894 | 32 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| mbed_official | 579:53297373a894 | 33 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| mbed_official | 579:53297373a894 | 34 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| mbed_official | 579:53297373a894 | 35 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| mbed_official | 579:53297373a894 | 36 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| mbed_official | 579:53297373a894 | 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| mbed_official | 579:53297373a894 | 38 | * POSSIBILITY OF SUCH DAMAGE. |
| mbed_official | 579:53297373a894 | 39 | * |
| mbed_official | 579:53297373a894 | 40 | * \asf_license_stop |
| mbed_official | 579:53297373a894 | 41 | * |
| mbed_official | 579:53297373a894 | 42 | */ |
| mbed_official | 579:53297373a894 | 43 | /** |
| mbed_official | 579:53297373a894 | 44 | * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a> |
| mbed_official | 579:53297373a894 | 45 | */ |
| mbed_official | 579:53297373a894 | 46 | |
| mbed_official | 579:53297373a894 | 47 | #include <gclk.h> |
| mbed_official | 579:53297373a894 | 48 | #include <clock.h> |
| mbed_official | 579:53297373a894 | 49 | #include <system_interrupt.h> |
| mbed_official | 579:53297373a894 | 50 | |
| mbed_official | 579:53297373a894 | 51 | /** |
| mbed_official | 579:53297373a894 | 52 | * \brief Determines if the hardware module(s) are currently synchronizing to the bus. |
| mbed_official | 579:53297373a894 | 53 | * |
| mbed_official | 579:53297373a894 | 54 | * Checks to see if the underlying hardware peripheral module(s) are currently |
| mbed_official | 579:53297373a894 | 55 | * synchronizing across multiple clock domains to the hardware bus, This |
| mbed_official | 579:53297373a894 | 56 | * function can be used to delay further operations on a module until such time |
| mbed_official | 579:53297373a894 | 57 | * that it is ready, to prevent blocking delays for synchronization in the |
| mbed_official | 579:53297373a894 | 58 | * user application. |
| mbed_official | 579:53297373a894 | 59 | * |
| mbed_official | 579:53297373a894 | 60 | * \return Synchronization status of the underlying hardware module(s). |
| mbed_official | 579:53297373a894 | 61 | * |
| mbed_official | 579:53297373a894 | 62 | * \retval false if the module has completed synchronization |
| mbed_official | 579:53297373a894 | 63 | * \retval true if the module synchronization is ongoing |
| mbed_official | 579:53297373a894 | 64 | */ |
| mbed_official | 579:53297373a894 | 65 | static inline bool system_gclk_is_syncing(void) |
| mbed_official | 579:53297373a894 | 66 | { |
| mbed_official | 579:53297373a894 | 67 | if (GCLK->STATUS.reg & GCLK_STATUS_SYNCBUSY) { |
| mbed_official | 579:53297373a894 | 68 | return true; |
| mbed_official | 579:53297373a894 | 69 | } |
| mbed_official | 579:53297373a894 | 70 | |
| mbed_official | 579:53297373a894 | 71 | return false; |
| mbed_official | 579:53297373a894 | 72 | } |
| mbed_official | 579:53297373a894 | 73 | |
| mbed_official | 579:53297373a894 | 74 | /** |
| mbed_official | 579:53297373a894 | 75 | * \brief Initializes the GCLK driver. |
| mbed_official | 579:53297373a894 | 76 | * |
| mbed_official | 579:53297373a894 | 77 | * Initializes the Generic Clock module, disabling and resetting all active |
| mbed_official | 579:53297373a894 | 78 | * Generic Clock Generators and Channels to their power-on default values. |
| mbed_official | 579:53297373a894 | 79 | */ |
| mbed_official | 579:53297373a894 | 80 | void system_gclk_init(void) |
| mbed_official | 579:53297373a894 | 81 | { |
| mbed_official | 579:53297373a894 | 82 | /* Turn on the digital interface clock */ |
| mbed_official | 579:53297373a894 | 83 | system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBA, PM_APBAMASK_GCLK); |
| mbed_official | 579:53297373a894 | 84 | |
| mbed_official | 579:53297373a894 | 85 | /* Software reset the module to ensure it is re-initialized correctly */ |
| mbed_official | 579:53297373a894 | 86 | GCLK->CTRL.reg = GCLK_CTRL_SWRST; |
| mbed_official | 579:53297373a894 | 87 | while (GCLK->CTRL.reg & GCLK_CTRL_SWRST) { |
| mbed_official | 579:53297373a894 | 88 | /* Wait for reset to complete */ |
| mbed_official | 579:53297373a894 | 89 | } |
| mbed_official | 579:53297373a894 | 90 | } |
| mbed_official | 579:53297373a894 | 91 | |
| mbed_official | 579:53297373a894 | 92 | /** |
| mbed_official | 579:53297373a894 | 93 | * \brief Writes a Generic Clock Generator configuration to the hardware module. |
| mbed_official | 579:53297373a894 | 94 | * |
| mbed_official | 579:53297373a894 | 95 | * Writes out a given configuration of a Generic Clock Generator configuration |
| mbed_official | 579:53297373a894 | 96 | * to the hardware module. |
| mbed_official | 579:53297373a894 | 97 | * |
| mbed_official | 579:53297373a894 | 98 | * \note Changing the clock source on the fly (on a running |
| mbed_official | 579:53297373a894 | 99 | * generator) can take additional time if the clock source is configured |
| mbed_official | 579:53297373a894 | 100 | * to only run on-demand (ONDEMAND bit is set) and it is not currently |
| mbed_official | 579:53297373a894 | 101 | * running (no peripheral is requesting the clock source). In this case |
| mbed_official | 579:53297373a894 | 102 | * the GCLK will request the new clock while still keeping a request to |
| mbed_official | 579:53297373a894 | 103 | * the old clock source until the new clock source is ready. |
| mbed_official | 579:53297373a894 | 104 | * |
| mbed_official | 579:53297373a894 | 105 | * \note This function will not start a generator that is not already running; |
| mbed_official | 579:53297373a894 | 106 | * to start the generator, call \ref system_gclk_gen_enable() |
| mbed_official | 579:53297373a894 | 107 | * after configuring a generator. |
| mbed_official | 579:53297373a894 | 108 | * |
| mbed_official | 579:53297373a894 | 109 | * \param[in] generator Generic Clock Generator index to configure |
| mbed_official | 579:53297373a894 | 110 | * \param[in] config Configuration settings for the generator |
| mbed_official | 579:53297373a894 | 111 | */ |
| mbed_official | 579:53297373a894 | 112 | void system_gclk_gen_set_config( |
| mbed_official | 579:53297373a894 | 113 | const uint8_t generator, |
| mbed_official | 579:53297373a894 | 114 | struct system_gclk_gen_config *const config) |
| mbed_official | 579:53297373a894 | 115 | { |
| mbed_official | 579:53297373a894 | 116 | /* Sanity check arguments */ |
| mbed_official | 579:53297373a894 | 117 | Assert(config); |
| mbed_official | 579:53297373a894 | 118 | |
| mbed_official | 579:53297373a894 | 119 | /* Cache new register configurations to minimize sync requirements. */ |
| mbed_official | 579:53297373a894 | 120 | uint32_t new_genctrl_config = (generator << GCLK_GENCTRL_ID_Pos); |
| mbed_official | 579:53297373a894 | 121 | uint32_t new_gendiv_config = (generator << GCLK_GENDIV_ID_Pos); |
| mbed_official | 579:53297373a894 | 122 | |
| mbed_official | 579:53297373a894 | 123 | /* Select the requested source clock for the generator */ |
| mbed_official | 579:53297373a894 | 124 | new_genctrl_config |= config->source_clock << GCLK_GENCTRL_SRC_Pos; |
| mbed_official | 579:53297373a894 | 125 | |
| mbed_official | 579:53297373a894 | 126 | /* Configure the clock to be either high or low when disabled */ |
| mbed_official | 579:53297373a894 | 127 | if (config->high_when_disabled) { |
| mbed_official | 579:53297373a894 | 128 | new_genctrl_config |= GCLK_GENCTRL_OOV; |
| mbed_official | 579:53297373a894 | 129 | } |
| mbed_official | 579:53297373a894 | 130 | |
| mbed_official | 579:53297373a894 | 131 | /* Configure if the clock output to I/O pin should be enabled. */ |
| mbed_official | 579:53297373a894 | 132 | if (config->output_enable) { |
| mbed_official | 579:53297373a894 | 133 | new_genctrl_config |= GCLK_GENCTRL_OE; |
| mbed_official | 579:53297373a894 | 134 | } |
| mbed_official | 579:53297373a894 | 135 | |
| mbed_official | 579:53297373a894 | 136 | /* Set division factor */ |
| mbed_official | 579:53297373a894 | 137 | if (config->division_factor > 1) { |
| mbed_official | 579:53297373a894 | 138 | /* Check if division is a power of two */ |
| mbed_official | 579:53297373a894 | 139 | if (((config->division_factor & (config->division_factor - 1)) == 0)) { |
| mbed_official | 579:53297373a894 | 140 | /* Determine the index of the highest bit set to get the |
| mbed_official | 579:53297373a894 | 141 | * division factor that must be loaded into the division |
| mbed_official | 579:53297373a894 | 142 | * register */ |
| mbed_official | 579:53297373a894 | 143 | |
| mbed_official | 579:53297373a894 | 144 | uint32_t div2_count = 0; |
| mbed_official | 579:53297373a894 | 145 | |
| mbed_official | 579:53297373a894 | 146 | uint32_t mask; |
| mbed_official | 579:53297373a894 | 147 | for (mask = (1UL << 1); mask < config->division_factor; |
| mbed_official | 579:53297373a894 | 148 | mask <<= 1) { |
| mbed_official | 579:53297373a894 | 149 | div2_count++; |
| mbed_official | 579:53297373a894 | 150 | } |
| mbed_official | 579:53297373a894 | 151 | |
| mbed_official | 579:53297373a894 | 152 | /* Set binary divider power of 2 division factor */ |
| mbed_official | 579:53297373a894 | 153 | new_gendiv_config |= div2_count << GCLK_GENDIV_DIV_Pos; |
| mbed_official | 579:53297373a894 | 154 | new_genctrl_config |= GCLK_GENCTRL_DIVSEL; |
| mbed_official | 579:53297373a894 | 155 | } else { |
| mbed_official | 579:53297373a894 | 156 | /* Set integer division factor */ |
| mbed_official | 579:53297373a894 | 157 | |
| mbed_official | 579:53297373a894 | 158 | new_gendiv_config |= |
| mbed_official | 579:53297373a894 | 159 | (config->division_factor) << GCLK_GENDIV_DIV_Pos; |
| mbed_official | 579:53297373a894 | 160 | |
| mbed_official | 579:53297373a894 | 161 | /* Enable non-binary division with increased duty cycle accuracy */ |
| mbed_official | 579:53297373a894 | 162 | new_genctrl_config |= GCLK_GENCTRL_IDC; |
| mbed_official | 579:53297373a894 | 163 | } |
| mbed_official | 579:53297373a894 | 164 | |
| mbed_official | 579:53297373a894 | 165 | } |
| mbed_official | 579:53297373a894 | 166 | |
| mbed_official | 579:53297373a894 | 167 | /* Enable or disable the clock in standby mode */ |
| mbed_official | 579:53297373a894 | 168 | if (config->run_in_standby) { |
| mbed_official | 579:53297373a894 | 169 | new_genctrl_config |= GCLK_GENCTRL_RUNSTDBY; |
| mbed_official | 579:53297373a894 | 170 | } |
| mbed_official | 579:53297373a894 | 171 | |
| mbed_official | 579:53297373a894 | 172 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 173 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 174 | }; |
| mbed_official | 579:53297373a894 | 175 | |
| mbed_official | 579:53297373a894 | 176 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 177 | |
| mbed_official | 579:53297373a894 | 178 | /* Select the correct generator */ |
| mbed_official | 579:53297373a894 | 179 | *((uint8_t*)&GCLK->GENDIV.reg) = generator; |
| mbed_official | 579:53297373a894 | 180 | |
| mbed_official | 579:53297373a894 | 181 | /* Write the new generator configuration */ |
| mbed_official | 579:53297373a894 | 182 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 183 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 184 | }; |
| mbed_official | 579:53297373a894 | 185 | GCLK->GENDIV.reg = new_gendiv_config; |
| mbed_official | 579:53297373a894 | 186 | |
| mbed_official | 579:53297373a894 | 187 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 188 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 189 | }; |
| mbed_official | 579:53297373a894 | 190 | GCLK->GENCTRL.reg = new_genctrl_config | (GCLK->GENCTRL.reg & GCLK_GENCTRL_GENEN); |
| mbed_official | 579:53297373a894 | 191 | |
| mbed_official | 579:53297373a894 | 192 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 193 | } |
| mbed_official | 579:53297373a894 | 194 | |
| mbed_official | 579:53297373a894 | 195 | /** |
| mbed_official | 579:53297373a894 | 196 | * \brief Enables a Generic Clock Generator that was previously configured. |
| mbed_official | 579:53297373a894 | 197 | * |
| mbed_official | 579:53297373a894 | 198 | * Starts the clock generation of a Generic Clock Generator that was previously |
| mbed_official | 579:53297373a894 | 199 | * configured via a call to \ref system_gclk_gen_set_config(). |
| mbed_official | 579:53297373a894 | 200 | * |
| mbed_official | 579:53297373a894 | 201 | * \param[in] generator Generic Clock Generator index to enable |
| mbed_official | 579:53297373a894 | 202 | */ |
| mbed_official | 579:53297373a894 | 203 | void system_gclk_gen_enable( |
| mbed_official | 579:53297373a894 | 204 | const uint8_t generator) |
| mbed_official | 579:53297373a894 | 205 | { |
| mbed_official | 579:53297373a894 | 206 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 207 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 208 | }; |
| mbed_official | 579:53297373a894 | 209 | |
| mbed_official | 579:53297373a894 | 210 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 211 | |
| mbed_official | 579:53297373a894 | 212 | /* Select the requested generator */ |
| mbed_official | 579:53297373a894 | 213 | *((uint8_t*)&GCLK->GENCTRL.reg) = generator; |
| mbed_official | 579:53297373a894 | 214 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 215 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 216 | }; |
| mbed_official | 579:53297373a894 | 217 | |
| mbed_official | 579:53297373a894 | 218 | /* Enable generator */ |
| mbed_official | 579:53297373a894 | 219 | GCLK->GENCTRL.reg |= GCLK_GENCTRL_GENEN; |
| mbed_official | 579:53297373a894 | 220 | |
| mbed_official | 579:53297373a894 | 221 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 222 | } |
| mbed_official | 579:53297373a894 | 223 | |
| mbed_official | 579:53297373a894 | 224 | /** |
| mbed_official | 579:53297373a894 | 225 | * \brief Disables a Generic Clock Generator that was previously enabled. |
| mbed_official | 579:53297373a894 | 226 | * |
| mbed_official | 579:53297373a894 | 227 | * Stops the clock generation of a Generic Clock Generator that was previously |
| mbed_official | 579:53297373a894 | 228 | * started via a call to \ref system_gclk_gen_enable(). |
| mbed_official | 579:53297373a894 | 229 | * |
| mbed_official | 579:53297373a894 | 230 | * \param[in] generator Generic Clock Generator index to disable |
| mbed_official | 579:53297373a894 | 231 | */ |
| mbed_official | 579:53297373a894 | 232 | void system_gclk_gen_disable( |
| mbed_official | 579:53297373a894 | 233 | const uint8_t generator) |
| mbed_official | 579:53297373a894 | 234 | { |
| mbed_official | 579:53297373a894 | 235 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 236 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 237 | }; |
| mbed_official | 579:53297373a894 | 238 | |
| mbed_official | 579:53297373a894 | 239 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 240 | |
| mbed_official | 579:53297373a894 | 241 | /* Select the requested generator */ |
| mbed_official | 579:53297373a894 | 242 | *((uint8_t*)&GCLK->GENCTRL.reg) = generator; |
| mbed_official | 579:53297373a894 | 243 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 244 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 245 | }; |
| mbed_official | 579:53297373a894 | 246 | |
| mbed_official | 579:53297373a894 | 247 | /* Disable generator */ |
| mbed_official | 579:53297373a894 | 248 | GCLK->GENCTRL.reg &= ~GCLK_GENCTRL_GENEN; |
| mbed_official | 579:53297373a894 | 249 | while (GCLK->GENCTRL.reg & GCLK_GENCTRL_GENEN) { |
| mbed_official | 579:53297373a894 | 250 | /* Wait for clock to become disabled */ |
| mbed_official | 579:53297373a894 | 251 | } |
| mbed_official | 579:53297373a894 | 252 | |
| mbed_official | 579:53297373a894 | 253 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 254 | } |
| mbed_official | 579:53297373a894 | 255 | |
| mbed_official | 579:53297373a894 | 256 | /** |
| mbed_official | 579:53297373a894 | 257 | * \brief Determins if the specified Generic Clock Generator is enabled. |
| mbed_official | 579:53297373a894 | 258 | * |
| mbed_official | 579:53297373a894 | 259 | * \param[in] generator Generic Clock Generator index to check |
| mbed_official | 579:53297373a894 | 260 | * |
| mbed_official | 579:53297373a894 | 261 | * \return The enabled status. |
| mbed_official | 579:53297373a894 | 262 | * \retval true The Generic Clock Generator is enabled |
| mbed_official | 579:53297373a894 | 263 | * \retval false The Generic Clock Generator is disabled |
| mbed_official | 579:53297373a894 | 264 | */ |
| mbed_official | 579:53297373a894 | 265 | bool system_gclk_gen_is_enabled( |
| mbed_official | 579:53297373a894 | 266 | const uint8_t generator) |
| mbed_official | 579:53297373a894 | 267 | { |
| mbed_official | 579:53297373a894 | 268 | bool enabled; |
| mbed_official | 579:53297373a894 | 269 | |
| mbed_official | 579:53297373a894 | 270 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 271 | |
| mbed_official | 579:53297373a894 | 272 | /* Select the requested generator */ |
| mbed_official | 579:53297373a894 | 273 | *((uint8_t*)&GCLK->GENCTRL.reg) = generator; |
| mbed_official | 579:53297373a894 | 274 | /* Obtain the enabled status */ |
| mbed_official | 579:53297373a894 | 275 | enabled = (GCLK->GENCTRL.reg & GCLK_GENCTRL_GENEN); |
| mbed_official | 579:53297373a894 | 276 | |
| mbed_official | 579:53297373a894 | 277 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 278 | |
| mbed_official | 579:53297373a894 | 279 | return enabled; |
| mbed_official | 579:53297373a894 | 280 | } |
| mbed_official | 579:53297373a894 | 281 | |
| mbed_official | 579:53297373a894 | 282 | /** |
| mbed_official | 579:53297373a894 | 283 | * \brief Retrieves the clock frequency of a Generic Clock generator. |
| mbed_official | 579:53297373a894 | 284 | * |
| mbed_official | 579:53297373a894 | 285 | * Determines the clock frequency (in Hz) of a specified Generic Clock |
| mbed_official | 579:53297373a894 | 286 | * generator, used as a source to a Generic Clock Channel module. |
| mbed_official | 579:53297373a894 | 287 | * |
| mbed_official | 579:53297373a894 | 288 | * \param[in] generator Generic Clock Generator index |
| mbed_official | 579:53297373a894 | 289 | * |
| mbed_official | 579:53297373a894 | 290 | * \return The frequency of the generic clock generator, in Hz. |
| mbed_official | 579:53297373a894 | 291 | */ |
| mbed_official | 579:53297373a894 | 292 | uint32_t system_gclk_gen_get_hz( |
| mbed_official | 579:53297373a894 | 293 | const uint8_t generator) |
| mbed_official | 579:53297373a894 | 294 | { |
| mbed_official | 579:53297373a894 | 295 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 296 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 297 | }; |
| mbed_official | 579:53297373a894 | 298 | |
| mbed_official | 579:53297373a894 | 299 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 300 | |
| mbed_official | 579:53297373a894 | 301 | /* Select the appropriate generator */ |
| mbed_official | 579:53297373a894 | 302 | *((uint8_t*)&GCLK->GENCTRL.reg) = generator; |
| mbed_official | 579:53297373a894 | 303 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 304 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 305 | }; |
| mbed_official | 579:53297373a894 | 306 | |
| mbed_official | 579:53297373a894 | 307 | /* Get the frequency of the source connected to the GCLK generator */ |
| mbed_official | 579:53297373a894 | 308 | uint32_t gen_input_hz = system_clock_source_get_hz( |
| mbed_official | 579:53297373a894 | 309 | (enum system_clock_source)GCLK->GENCTRL.bit.SRC); |
| mbed_official | 579:53297373a894 | 310 | |
| mbed_official | 579:53297373a894 | 311 | *((uint8_t*)&GCLK->GENCTRL.reg) = generator; |
| mbed_official | 579:53297373a894 | 312 | |
| mbed_official | 579:53297373a894 | 313 | uint8_t divsel = GCLK->GENCTRL.bit.DIVSEL; |
| mbed_official | 579:53297373a894 | 314 | |
| mbed_official | 579:53297373a894 | 315 | /* Select the appropriate generator division register */ |
| mbed_official | 579:53297373a894 | 316 | *((uint8_t*)&GCLK->GENDIV.reg) = generator; |
| mbed_official | 579:53297373a894 | 317 | while (system_gclk_is_syncing()) { |
| mbed_official | 579:53297373a894 | 318 | /* Wait for synchronization */ |
| mbed_official | 579:53297373a894 | 319 | }; |
| mbed_official | 579:53297373a894 | 320 | |
| mbed_official | 579:53297373a894 | 321 | uint32_t divider = GCLK->GENDIV.bit.DIV; |
| mbed_official | 579:53297373a894 | 322 | |
| mbed_official | 579:53297373a894 | 323 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 324 | |
| mbed_official | 579:53297373a894 | 325 | /* Check if the generator is using fractional or binary division */ |
| mbed_official | 579:53297373a894 | 326 | if (!divsel && divider > 1) { |
| mbed_official | 579:53297373a894 | 327 | gen_input_hz /= divider; |
| mbed_official | 579:53297373a894 | 328 | } else if (divsel) { |
| mbed_official | 579:53297373a894 | 329 | gen_input_hz >>= (divider+1); |
| mbed_official | 579:53297373a894 | 330 | } |
| mbed_official | 579:53297373a894 | 331 | |
| mbed_official | 579:53297373a894 | 332 | return gen_input_hz; |
| mbed_official | 579:53297373a894 | 333 | } |
| mbed_official | 579:53297373a894 | 334 | |
| mbed_official | 579:53297373a894 | 335 | /** |
| mbed_official | 579:53297373a894 | 336 | * \brief Writes a Generic Clock configuration to the hardware module. |
| mbed_official | 579:53297373a894 | 337 | * |
| mbed_official | 579:53297373a894 | 338 | * Writes out a given configuration of a Generic Clock configuration to the |
| mbed_official | 579:53297373a894 | 339 | * hardware module. If the clock is currently running, it will be stopped. |
| mbed_official | 579:53297373a894 | 340 | * |
| mbed_official | 579:53297373a894 | 341 | * \note Once called the clock will not be running; to start the clock, |
| mbed_official | 579:53297373a894 | 342 | * call \ref system_gclk_chan_enable() after configuring a clock channel. |
| mbed_official | 579:53297373a894 | 343 | * |
| mbed_official | 579:53297373a894 | 344 | * \param[in] channel Generic Clock channel to configure |
| mbed_official | 579:53297373a894 | 345 | * \param[in] config Configuration settings for the clock |
| mbed_official | 579:53297373a894 | 346 | * |
| mbed_official | 579:53297373a894 | 347 | */ |
| mbed_official | 579:53297373a894 | 348 | void system_gclk_chan_set_config( |
| mbed_official | 579:53297373a894 | 349 | const uint8_t channel, |
| mbed_official | 579:53297373a894 | 350 | struct system_gclk_chan_config *const config) |
| mbed_official | 579:53297373a894 | 351 | { |
| mbed_official | 579:53297373a894 | 352 | /* Sanity check arguments */ |
| mbed_official | 579:53297373a894 | 353 | Assert(config); |
| mbed_official | 579:53297373a894 | 354 | |
| mbed_official | 579:53297373a894 | 355 | /* Cache the new config to reduce sync requirements */ |
| mbed_official | 579:53297373a894 | 356 | uint32_t new_clkctrl_config = (channel << GCLK_CLKCTRL_ID_Pos); |
| mbed_official | 579:53297373a894 | 357 | |
| mbed_official | 579:53297373a894 | 358 | /* Select the desired generic clock generator */ |
| mbed_official | 579:53297373a894 | 359 | new_clkctrl_config |= config->source_generator << GCLK_CLKCTRL_GEN_Pos; |
| mbed_official | 579:53297373a894 | 360 | |
| mbed_official | 579:53297373a894 | 361 | /* Disable generic clock channel */ |
| mbed_official | 579:53297373a894 | 362 | system_gclk_chan_disable(channel); |
| mbed_official | 579:53297373a894 | 363 | |
| mbed_official | 579:53297373a894 | 364 | /* Write the new configuration */ |
| mbed_official | 579:53297373a894 | 365 | GCLK->CLKCTRL.reg = new_clkctrl_config; |
| mbed_official | 579:53297373a894 | 366 | } |
| mbed_official | 579:53297373a894 | 367 | |
| mbed_official | 579:53297373a894 | 368 | /** |
| mbed_official | 579:53297373a894 | 369 | * \brief Enables a Generic Clock that was previously configured. |
| mbed_official | 579:53297373a894 | 370 | * |
| mbed_official | 579:53297373a894 | 371 | * Starts the clock generation of a Generic Clock that was previously |
| mbed_official | 579:53297373a894 | 372 | * configured via a call to \ref system_gclk_chan_set_config(). |
| mbed_official | 579:53297373a894 | 373 | * |
| mbed_official | 579:53297373a894 | 374 | * \param[in] channel Generic Clock channel to enable |
| mbed_official | 579:53297373a894 | 375 | */ |
| mbed_official | 579:53297373a894 | 376 | void system_gclk_chan_enable( |
| mbed_official | 579:53297373a894 | 377 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 378 | { |
| mbed_official | 579:53297373a894 | 379 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 380 | |
| mbed_official | 579:53297373a894 | 381 | /* Select the requested generator channel */ |
| mbed_official | 579:53297373a894 | 382 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 383 | |
| mbed_official | 579:53297373a894 | 384 | /* Enable the generic clock */ |
| mbed_official | 579:53297373a894 | 385 | GCLK->CLKCTRL.reg |= GCLK_CLKCTRL_CLKEN; |
| mbed_official | 579:53297373a894 | 386 | |
| mbed_official | 579:53297373a894 | 387 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 388 | } |
| mbed_official | 579:53297373a894 | 389 | |
| mbed_official | 579:53297373a894 | 390 | /** |
| mbed_official | 579:53297373a894 | 391 | * \brief Disables a Generic Clock that was previously enabled. |
| mbed_official | 579:53297373a894 | 392 | * |
| mbed_official | 579:53297373a894 | 393 | * Stops the clock generation of a Generic Clock that was previously started |
| mbed_official | 579:53297373a894 | 394 | * via a call to \ref system_gclk_chan_enable(). |
| mbed_official | 579:53297373a894 | 395 | * |
| mbed_official | 579:53297373a894 | 396 | * \param[in] channel Generic Clock channel to disable |
| mbed_official | 579:53297373a894 | 397 | */ |
| mbed_official | 579:53297373a894 | 398 | void system_gclk_chan_disable( |
| mbed_official | 579:53297373a894 | 399 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 400 | { |
| mbed_official | 579:53297373a894 | 401 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 402 | |
| mbed_official | 579:53297373a894 | 403 | /* Select the requested generator channel */ |
| mbed_official | 579:53297373a894 | 404 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 405 | |
| mbed_official | 579:53297373a894 | 406 | /* Sanity check WRTLOCK */ |
| mbed_official | 579:53297373a894 | 407 | Assert(!GCLK->CLKCTRL.bit.WRTLOCK); |
| mbed_official | 579:53297373a894 | 408 | |
| mbed_official | 579:53297373a894 | 409 | /* Switch to known-working source so that the channel can be disabled */ |
| mbed_official | 579:53297373a894 | 410 | uint32_t prev_gen_id = GCLK->CLKCTRL.bit.GEN; |
| mbed_official | 579:53297373a894 | 411 | GCLK->CLKCTRL.bit.GEN = 0; |
| mbed_official | 579:53297373a894 | 412 | |
| mbed_official | 579:53297373a894 | 413 | /* Disable the generic clock */ |
| mbed_official | 579:53297373a894 | 414 | GCLK->CLKCTRL.reg &= ~GCLK_CLKCTRL_CLKEN; |
| mbed_official | 579:53297373a894 | 415 | while (GCLK->CLKCTRL.reg & GCLK_CLKCTRL_CLKEN) { |
| mbed_official | 579:53297373a894 | 416 | /* Wait for clock to become disabled */ |
| mbed_official | 579:53297373a894 | 417 | } |
| mbed_official | 579:53297373a894 | 418 | |
| mbed_official | 579:53297373a894 | 419 | /* Restore previous configured clock generator */ |
| mbed_official | 579:53297373a894 | 420 | GCLK->CLKCTRL.bit.GEN = prev_gen_id; |
| mbed_official | 579:53297373a894 | 421 | |
| mbed_official | 579:53297373a894 | 422 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 423 | } |
| mbed_official | 579:53297373a894 | 424 | |
| mbed_official | 579:53297373a894 | 425 | /** |
| mbed_official | 579:53297373a894 | 426 | * \brief Determins if the specified Generic Clock channel is enabled. |
| mbed_official | 579:53297373a894 | 427 | * |
| mbed_official | 579:53297373a894 | 428 | * \param[in] channel Generic Clock Channel index |
| mbed_official | 579:53297373a894 | 429 | * |
| mbed_official | 579:53297373a894 | 430 | * \return The enabled status. |
| mbed_official | 579:53297373a894 | 431 | * \retval true The Generic Clock channel is enabled |
| mbed_official | 579:53297373a894 | 432 | * \retval false The Generic Clock channel is disabled |
| mbed_official | 579:53297373a894 | 433 | */ |
| mbed_official | 579:53297373a894 | 434 | bool system_gclk_chan_is_enabled( |
| mbed_official | 579:53297373a894 | 435 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 436 | { |
| mbed_official | 579:53297373a894 | 437 | bool enabled; |
| mbed_official | 579:53297373a894 | 438 | |
| mbed_official | 579:53297373a894 | 439 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 440 | |
| mbed_official | 579:53297373a894 | 441 | /* Select the requested generic clock channel */ |
| mbed_official | 579:53297373a894 | 442 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 443 | enabled = GCLK->CLKCTRL.bit.CLKEN; |
| mbed_official | 579:53297373a894 | 444 | |
| mbed_official | 579:53297373a894 | 445 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 446 | |
| mbed_official | 579:53297373a894 | 447 | return enabled; |
| mbed_official | 579:53297373a894 | 448 | } |
| mbed_official | 579:53297373a894 | 449 | |
| mbed_official | 579:53297373a894 | 450 | /** |
| mbed_official | 579:53297373a894 | 451 | * \brief Locks a Generic Clock channel from further configuration writes. |
| mbed_official | 579:53297373a894 | 452 | * |
| mbed_official | 579:53297373a894 | 453 | * Locks a generic clock channel from further configuration writes. It is only |
| mbed_official | 579:53297373a894 | 454 | * possible to unlock the channel configuration through a power on reset. |
| mbed_official | 579:53297373a894 | 455 | * |
| mbed_official | 579:53297373a894 | 456 | * \param[in] channel Generic Clock channel to enable |
| mbed_official | 579:53297373a894 | 457 | */ |
| mbed_official | 579:53297373a894 | 458 | void system_gclk_chan_lock( |
| mbed_official | 579:53297373a894 | 459 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 460 | { |
| mbed_official | 579:53297373a894 | 461 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 462 | |
| mbed_official | 579:53297373a894 | 463 | /* Select the requested generator channel */ |
| mbed_official | 579:53297373a894 | 464 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 465 | |
| mbed_official | 579:53297373a894 | 466 | /* Lock the generic clock */ |
| mbed_official | 579:53297373a894 | 467 | GCLK->CLKCTRL.reg |= GCLK_CLKCTRL_WRTLOCK; |
| mbed_official | 579:53297373a894 | 468 | |
| mbed_official | 579:53297373a894 | 469 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 470 | } |
| mbed_official | 579:53297373a894 | 471 | |
| mbed_official | 579:53297373a894 | 472 | /** |
| mbed_official | 579:53297373a894 | 473 | * \brief Determins if the specified Generic Clock channel is locked. |
| mbed_official | 579:53297373a894 | 474 | * |
| mbed_official | 579:53297373a894 | 475 | * \param[in] channel Generic Clock Channel index |
| mbed_official | 579:53297373a894 | 476 | * |
| mbed_official | 579:53297373a894 | 477 | * \return The lock status. |
| mbed_official | 579:53297373a894 | 478 | * \retval true The Generic Clock channel is locked |
| mbed_official | 579:53297373a894 | 479 | * \retval false The Generic Clock channel is not locked |
| mbed_official | 579:53297373a894 | 480 | */ |
| mbed_official | 579:53297373a894 | 481 | bool system_gclk_chan_is_locked( |
| mbed_official | 579:53297373a894 | 482 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 483 | { |
| mbed_official | 579:53297373a894 | 484 | bool locked; |
| mbed_official | 579:53297373a894 | 485 | |
| mbed_official | 579:53297373a894 | 486 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 487 | |
| mbed_official | 579:53297373a894 | 488 | /* Select the requested generic clock channel */ |
| mbed_official | 579:53297373a894 | 489 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 490 | locked = GCLK->CLKCTRL.bit.WRTLOCK; |
| mbed_official | 579:53297373a894 | 491 | |
| mbed_official | 579:53297373a894 | 492 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 493 | |
| mbed_official | 579:53297373a894 | 494 | return locked; |
| mbed_official | 579:53297373a894 | 495 | } |
| mbed_official | 579:53297373a894 | 496 | |
| mbed_official | 579:53297373a894 | 497 | /** |
| mbed_official | 579:53297373a894 | 498 | * \brief Retrieves the clock frequency of a Generic Clock channel. |
| mbed_official | 579:53297373a894 | 499 | * |
| mbed_official | 579:53297373a894 | 500 | * Determines the clock frequency (in Hz) of a specified Generic Clock |
| mbed_official | 579:53297373a894 | 501 | * channel, used as a source to a device peripheral module. |
| mbed_official | 579:53297373a894 | 502 | * |
| mbed_official | 579:53297373a894 | 503 | * \param[in] channel Generic Clock Channel index |
| mbed_official | 579:53297373a894 | 504 | * |
| mbed_official | 579:53297373a894 | 505 | * \return The frequency of the generic clock channel, in Hz. |
| mbed_official | 579:53297373a894 | 506 | */ |
| mbed_official | 579:53297373a894 | 507 | uint32_t system_gclk_chan_get_hz( |
| mbed_official | 579:53297373a894 | 508 | const uint8_t channel) |
| mbed_official | 579:53297373a894 | 509 | { |
| mbed_official | 579:53297373a894 | 510 | uint8_t gen_id; |
| mbed_official | 579:53297373a894 | 511 | |
| mbed_official | 579:53297373a894 | 512 | system_interrupt_enter_critical_section(); |
| mbed_official | 579:53297373a894 | 513 | |
| mbed_official | 579:53297373a894 | 514 | /* Select the requested generic clock channel */ |
| mbed_official | 579:53297373a894 | 515 | *((uint8_t*)&GCLK->CLKCTRL.reg) = channel; |
| mbed_official | 579:53297373a894 | 516 | gen_id = GCLK->CLKCTRL.bit.GEN; |
| mbed_official | 579:53297373a894 | 517 | |
| mbed_official | 579:53297373a894 | 518 | system_interrupt_leave_critical_section(); |
| mbed_official | 579:53297373a894 | 519 | |
| mbed_official | 579:53297373a894 | 520 | /* Return the clock speed of the associated GCLK generator */ |
| mbed_official | 579:53297373a894 | 521 | return system_gclk_gen_get_hz(gen_id); |
| mbed_official | 579:53297373a894 | 522 | } |