/*************************************************************************
* OK335xS UART device registe hacking
* 声明：
* 1. 本文是对OK335xS Linux内核中UART设备注册代码进行跟踪；
* 2. 本人在文中采用函数调用线路图进行标记，方便阅读；
* 3. 代码跟踪的用的是vim+ctags；
*
* 2015-6-30 晴 深圳 南山平山村 曾剑锋
************************************************************************/
\\\\\\\\\\\-*- 目录 -*-/////////
| 一、板级文件：
| 二、跟踪am33xx_init_early：
| 三、跟踪am335x_evm_init：
\\\\\\\\\\\\\\\\\//////////////
一、板级文件：
MACHINE_START(AM335XEVM, "am335xevm")
/* Maintainer: Texas Instruments */
.atag_offset = 0x100,
.map_io = am335x_evm_map_io,
.init_early = am33xx_init_early, // 跟踪该函数
.init_irq = ti81xx_init_irq,
.handle_irq = omap3_intc_handle_irq,
.timer = &omap3_am33xx_timer,
.init_machine = am335x_evm_init, // 跟踪该函数
MACHINE_END
MACHINE_START(AM335XIAEVM, "am335xiaevm")
/* Maintainer: Texas Instruments */
.atag_offset = 0x100,
.map_io = am335x_evm_map_io,
.init_irq = ti81xx_init_irq,
.init_early = am33xx_init_early,
.timer = &omap3_am33xx_timer,
.init_machine = am335x_evm_init,
MACHINE_END
二、跟踪am33xx_init_early：
void __init am33xx_init_early(void)
{
omap2_set_globals_am33xx();
omap3xxx_check_revision();
am33xx_check_features();
omap_common_init_early();
am33xx_voltagedomains_init();
omap44xx_prminst_init();
am33xx_powerdomains_init();
omap44xx_cminst_init();
am33xx_clockdomains_init();
am33xx_hwmod_init(); ---->--------+
omap_hwmod_init_postsetup(); |
omap3xxx_clk_init(); |
} |
|
int __init am33xx_hwmod_init(void) <---+
{
return omap_hwmod_register(am33xx_hwmods); -------------+
} | |
V |
static __initdata struct omap_hwmod *am33xx_hwmods[] = { |
...... |
/* uart class */ |
&am33xx_uart1_hwmod, ----+ |
&am33xx_uart2_hwmod, | |
&am33xx_uart3_hwmod, | |
&am33xx_uart4_hwmod, | |
&am33xx_uart5_hwmod, | |
&am33xx_uart6_hwmod, | |
...... | |
} | |
V |
static struct omap_hwmod am33xx_uart1_hwmod = { |
.name = "uart1", // 后续注册设备时会用到name |
.class = &uart_class, ->----+ |
.clkdm_name = "l4_wkup_clkdm", | |
.mpu_irqs = am33xx_uart1_irqs, -*-------+ |
.main_clk = "uart1_fck", | | |
.sdma_reqs = uart1_edma_reqs, --*-------*----------+ |
...... | | | |
}; | | | |
V | | |
static struct omap_hwmod_class uart_class = { | | |
.name = "uart", | | |
.sysc = &uart_sysc, | | |
}; | | |
| | |
/* uart1 */ V | |
static struct omap_hwmod_dma_info uart1_edma_reqs[] = { | |
{ .name = "tx", .dma_req = 26, }, | |
{ .name = "rx", .dma_req = 27, }, | |
{ .dma_req = -1 } +--------------+ |
}; | |
V |
static struct omap_hwmod_irq_info am33xx_uart1_irqs[] = { |
{ .irq = 72 }, |
{ .irq = -1 } |
}; |
|
int __init omap_hwmod_register(struct omap_hwmod **ohs) <------+
{
int r, i;
if (!ohs)
return 0;
i = 0;
do {
r = _register(ohs[i]); ------------------------------------+
WARN(r, "omap_hwmod: %s: _register returned %d\n", ohs[i]->name, |
r); |
} while (ohs[++i]); |
|
return 0; |
} |
|
static int __init _register(struct omap_hwmod *oh) <---------------------+
{
int ms_id;
if (!oh || !oh->name || !oh->class || !oh->class->name ||
(oh->_state != _HWMOD_STATE_UNKNOWN))
return -EINVAL;
pr_debug("omap_hwmod: %s: registering\n", oh->name);
if (_lookup(oh->name))
return -EEXIST;
ms_id = _find_mpu_port_index(oh);
if (!IS_ERR_VALUE(ms_id))
oh->_mpu_port_index = ms_id;
else
oh->_int_flags |= _HWMOD_NO_MPU_PORT;
list_add_tail(&oh->node, &omap_hwmod_list);
spin_lock_init(&oh->_lock);
oh->_state = _HWMOD_STATE_REGISTERED;
/*
* XXX Rather than doing a strcmp(), this should test a flag
* set in the hwmod data, inserted by the autogenerator code.
*/
if (!strcmp(oh->name, MPU_INITIATOR_NAME))
mpu_oh = oh;
return 0;
}
三、跟踪am335x_evm_init：
static void __init am335x_evm_init(void)
{
am33xx_cpuidle_init();
am33xx_mux_init(board_mux);
omap_serial_init(); ------------------------------------------+
am335x_evm_i2c_init(); |
omap_sdrc_init(NULL, NULL); |
usb_musb_init(&musb_board_data); |
omap_board_config = am335x_evm_config; |
omap_board_config_size = ARRAY_SIZE(am335x_evm_config); |
/* Create an alias for icss clock */ |
if (clk_add_alias("pruss", NULL, "pruss_uart_gclk", NULL)) |
pr_warn("failed to create an alias: icss_uart_gclk --> pruss\n"); |
/* Create an alias for gfx/sgx clock */ |
if (clk_add_alias("sgx_ck", NULL, "gfx_fclk", NULL)) |
pr_warn("failed to create an alias: gfx_fclk --> sgx_ck\n"); |
|
printk("zengjf test code 1.\n"); |
} |
|
void __init omap_serial_init(void) <---------------------------------+
{
omap_serial_board_init(NULL); -------+
} +-----------------+
V
void __init omap_serial_board_init(struct omap_uart_port_info *info)
{
struct omap_uart_state *uart;
struct omap_board_data bdata;
list_for_each_entry(uart, &uart_list, node) {
bdata.id = uart->num; ^---------------------------------+
bdata.flags = 0; |
bdata.pads = NULL; |
bdata.pads_cnt = 0; |
|
if (cpu_is_omap44xx() || (cpu_is_omap34xx() && |
!cpu_is_am33xx())) |
omap_serial_fill_default_pads(&bdata); |
|
if (!info) |
omap_serial_init_port(&bdata, NULL); -------------------*---+
else | |
omap_serial_init_port(&bdata, &info[uart->num]); | |
} | |
} | |
| |
static int __init omap_serial_early_init(void) | |
{ | |
do { | |
...... | |
snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN, | |
"uart%d", num_uarts + 1); | |
oh = omap_hwmod_lookup(oh_name); ----------------------+ | |
if (!oh) | | |
break; | | |
| | |
uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);| | |
if (WARN_ON(!uart)) | | |
return -ENODEV; | | |
| | |
uart->oh = oh; | | |
uart->num = num_uarts++; | | |
list_add_tail(&uart->node, &uart_list); <------*--+ |
...... | | |
} while (1); | | |
| | |
return 0; | | |
} // 这里很重要 | | |
core_initcall(omap_serial_early_init); <------*--+ |
| |
struct omap_hwmod *omap_hwmod_lookup(const char *name) <------ + |
{ |
struct omap_hwmod *oh; |
|
if (!name) |
return NULL; |
|
oh = _lookup(name); ----+ |
| |
return oh; | |
} | |
V |
static struct omap_hwmod *_lookup(const char *name) |
{ |
struct omap_hwmod *oh, *temp_oh; |
|
oh = NULL; |
|
list_for_each_entry(temp_oh, &omap_hwmod_list, node) { |
if (!strcmp(name, temp_oh->name)) { |
oh = temp_oh; |
break; |
} |
} |
|
return oh; |
} +-------------------------------------------------+
V
void __init omap_serial_init_port(struct omap_board_data *bdata,
struct omap_uart_port_info *info)
{
struct omap_uart_state *uart;
struct omap_hwmod *oh;
struct platform_device *pdev;
void *pdata = NULL;
u32 pdata_size = 0;
char *name;
struct omap_uart_port_info omap_up;
if (WARN_ON(!bdata))
return;
if (WARN_ON(bdata->id < 0))
return;
if (WARN_ON(bdata->id >= num_uarts))
return;
list_for_each_entry(uart, &uart_list, node)
if (bdata->id == uart->num)
break;
if (!info)
info = omap_serial_default_info;
oh = uart->oh;
name = DRIVER_NAME;
omap_up.dma_enabled = info->dma_enabled;
omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
omap_up.flags = UPF_BOOT_AUTOCONF;
omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
omap_up.set_forceidle = omap_uart_set_forceidle;
omap_up.set_noidle = omap_uart_set_noidle;
omap_up.enable_wakeup = omap_uart_enable_wakeup;
omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
omap_up.dma_rx_timeout = info->dma_rx_timeout;
omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
omap_up.autosuspend_timeout = info->autosuspend_timeout;
/* Enable the MDR1 Errata i202 for OMAP2430/3xxx/44xx */
if (!cpu_is_omap2420() && !cpu_is_ti816x())
omap_up.errata |= UART_ERRATA_i202_MDR1_ACCESS;
/* Enable DMA Mode Force Idle Errata i291 for omap34xx/3630 */
if ((cpu_is_omap34xx() || cpu_is_omap3630()) && !cpu_is_am33xx())
omap_up.errata |= UART_ERRATA_i291_DMA_FORCEIDLE;
pdata = &omap_up;
pdata_size = sizeof(struct omap_uart_port_info);
if (WARN_ON(!oh))
return;
pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size, ------+
NULL, 0, false); |
WARN(IS_ERR(pdev), "Could not build omap_device for %s: %s.\n", |
name, oh->name); |
|
if ((console_uart_id == bdata->id) && no_console_suspend) |
omap_device_disable_idle_on_suspend(pdev); |
|
oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt); |
|
uart->pdev = pdev; |
|
oh->dev_attr = uart; |
|
if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads) |
&& !uart_debug) |
device_init_wakeup(&pdev->dev, true); |
} +------------------------------------------+
V
struct platform_device *omap_device_build(const char *pdev_name, int pdev_id,
struct omap_hwmod *oh, void *pdata,
int pdata_len,
struct omap_device_pm_latency *pm_lats,
int pm_lats_cnt, int is_early_device)
{
struct omap_hwmod *ohs[] = { oh };
if (!oh)
return ERR_PTR(-EINVAL);
return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata, -----+
pdata_len, pm_lats, pm_lats_cnt, |
is_early_device); |
} +----------------------------------------+
|
V
struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
struct omap_hwmod **ohs, int oh_cnt,
void *pdata, int pdata_len,
struct omap_device_pm_latency *pm_lats,
int pm_lats_cnt, int is_early_device)
{
int ret = -ENOMEM;
struct platform_device *pdev;
struct omap_device *od;
if (!ohs || oh_cnt == 0 || !pdev_name)
return ERR_PTR(-EINVAL);
if (!pdata && pdata_len > 0)
return ERR_PTR(-EINVAL);
pdev = platform_device_alloc(pdev_name, pdev_id);
if (!pdev) {
ret = -ENOMEM;
goto odbs_exit;
}
/* Set the dev_name early to allow dev_xxx in omap_device_alloc */
if (pdev->id != -1)
dev_set_name(&pdev->dev, "%s.%d", pdev->name, pdev->id);
else
dev_set_name(&pdev->dev, "%s", pdev->name);
od = omap_device_alloc(pdev, ohs, oh_cnt, pm_lats, pm_lats_cnt);
if (!od)
goto odbs_exit1;
ret = platform_device_add_data(pdev, pdata, pdata_len);
if (ret)
goto odbs_exit2;
if (is_early_device)
ret = omap_early_device_register(pdev); -----------------------+
else |
ret = omap_device_register(pdev); --------------------+ |
if (ret) | |
goto odbs_exit2; | |
| |
return pdev; | |
| |
odbs_exit2: | |
omap_device_delete(od); | |
odbs_exit1: | |
platform_device_put(pdev); | |
odbs_exit: | |
| |
pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret); | |
| |
return ERR_PTR(ret); | |
} | |
| |
| |
static int omap_early_device_register(struct platform_device *pdev) <--+ |
{ |
struct platform_device *devices[1]; |
|
devices[0] = pdev; |
early_platform_add_devices(devices, 1); |
return 0; |
} |
|
int omap_device_register(struct platform_device *pdev) <-------------+
{
pr_debug("omap_device: %s: registering\n", pdev->name);
pdev->dev.parent = &omap_device_parent;
pdev->dev.pm_domain = &omap_device_pm_domain;
return platform_device_add(pdev);
}
