u-boot/arch/arm/mach-snapdragon/clock-apq8016.c

/*
 * Clock drivers for Qualcomm APQ8016
 *
 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
 *
 * Based on Little Kernel driver, simplified
 *
 * SPDX-License-Identifier:	BSD-3-Clause
 */

#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <errno.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include "clock-snapdragon.h"

/* GPLL0 clock control registers */
#define GPLL0_STATUS_ACTIVE BIT(17)
#define APCS_GPLL_ENA_VOTE_GPLL0 BIT(0)

static const struct bcr_regs sdc_regs[] = {
	{
	.cfg_rcgr = SDCC_CFG_RCGR(1),
	.cmd_rcgr = SDCC_CMD_RCGR(1),
	.M = SDCC_M(1),
	.N = SDCC_N(1),
	.D = SDCC_D(1),
	},
	{
	.cfg_rcgr = SDCC_CFG_RCGR(2),
	.cmd_rcgr = SDCC_CMD_RCGR(2),
	.M = SDCC_M(2),
	.N = SDCC_N(2),
	.D = SDCC_D(2),
	}
};

static struct gpll0_ctrl gpll0_ctrl = {
	.status = GPLL0_STATUS,
	.status_bit = GPLL0_STATUS_ACTIVE,
	.ena_vote = APCS_GPLL_ENA_VOTE,
	.vote_bit = APCS_GPLL_ENA_VOTE_GPLL0,
};

/* SDHCI */
static int clk_init_sdc(struct msm_clk_priv *priv, int slot, uint rate)
{
	int div = 8; /* 100MHz default */

	if (rate == 200000000)
		div = 4;

	clk_enable_cbc(priv->base + SDCC_AHB_CBCR(slot));
	/* 800Mhz/div, gpll0 */
	clk_rcg_set_rate_mnd(priv->base, &sdc_regs[slot], div, 0, 0,
			     CFG_CLK_SRC_GPLL0);
	clk_enable_gpll0(priv->base, &gpll0_ctrl);
	clk_enable_cbc(priv->base + SDCC_APPS_CBCR(slot));

	return rate;
}

static const struct bcr_regs uart2_regs = {
	.cfg_rcgr = BLSP1_UART2_APPS_CFG_RCGR,
	.cmd_rcgr = BLSP1_UART2_APPS_CMD_RCGR,
	.M = BLSP1_UART2_APPS_M,
	.N = BLSP1_UART2_APPS_N,
	.D = BLSP1_UART2_APPS_D,
};

/* UART: 115200 */
static int clk_init_uart(struct msm_clk_priv *priv)
{
	/* Enable iface clk */
	clk_enable_cbc(priv->base + BLSP1_AHB_CBCR);
	/* 7372800 uart block clock @ GPLL0 */
	clk_rcg_set_rate_mnd(priv->base, &uart2_regs, 1, 144, 15625,
			     CFG_CLK_SRC_GPLL0);
	clk_enable_gpll0(priv->base, &gpll0_ctrl);
	/* Enable core clk */
	clk_enable_cbc(priv->base + BLSP1_UART2_APPS_CBCR);

	return 0;
}

ulong msm_set_rate(struct clk *clk, ulong rate)
{
	struct msm_clk_priv *priv = dev_get_priv(clk->dev);

	switch (clk->id) {
	case 0: /* SDC1 */
		return clk_init_sdc(priv, 0, rate);
		break;
	case 1: /* SDC2 */
		return clk_init_sdc(priv, 1, rate);
		break;
	case 4: /* UART2 */
		return clk_init_uart(priv);
		break;
	default:
		return 0;
	}
}