embox

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/**
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 * @file
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 * @brief PowerPC Microprocessor Family clock device driver
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 *
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 * @date 06.11.12
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 * @author Ilia Vaprol
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 */
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#include <asm/psr.h>
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#include <asm/regs.h>
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#include <embox/unit.h>
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#include <hal/clock.h>
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#include <hal/system.h>
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#include <kernel/irq.h>
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#include <kernel/time/clock_source.h>
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#include <stdint.h>
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/** Test for different frequancy (300K ticks -- i.e. 5min)
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 * 300MHz is 00:04:10.356 (300K)
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 * 333MHz is 00:04:37.672 (300K)
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 * 350MHz is 00:05:22.747 (300K)
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 * 366MHz is 00:05:39.987 (300K)
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 * 375MHz is 00:06:27.322 (343K)
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 * We will use 333MHz as default settings
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 */
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#define PPCCLK_IRQ  10
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#define PPCCLK_FREQ SYS_CLOCK
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#define PPCCLK_DECR (PPCCLK_FREQ / 1000) /* precision for ms */
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static irq_return_t clock_handler(unsigned int irq_nr, void *data) {
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	__set_tsr(__get_tsr() & ~TSR_DIS);
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	clock_tick_handler( data);
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	return IRQ_HANDLED;
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}
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static int ppc_clk_set_periodic(struct clock_source *cs) {
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	__set_dec(PPCCLK_DECR);
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	__set_decar(PPCCLK_DECR);
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    __set_tcr(TCR_DIE | TCR_ARE);
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	return 0;
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}
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static cycle_t ppc_clk_read(struct clock_source *cs) {
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	uint32_t l, u, tmp;
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	tmp = __get_tbu();
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	do {
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		u = tmp;
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		l = __get_tbl();
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		tmp = __get_tbu();
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	} while (tmp != u);
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	return ((uint64_t)u << 32) | l;
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}
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static struct time_event_device ppc_clk_event = {
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	.set_periodic = ppc_clk_set_periodic,
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	.irq_nr = PPCCLK_IRQ,
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};
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static struct time_counter_device ppc_clk_counter = {
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	.read = ppc_clk_read,
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	.cycle_hz = PPCCLK_FREQ,
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};
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static int ppc_clk_init(struct clock_source *cs) {
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	return irq_attach(PPCCLK_IRQ, clock_handler, 0, cs, "ppc_clk");
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}
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CLOCK_SOURCE_DEF(ppc_clk, ppc_clk_init, NULL,
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	&ppc_clk_event, &ppc_clk_counter);
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