MIPS: ath79: add clock setup code for the QCA955X SoCs

The patch adds code to get various clock frequencies
from the PLLs used in the QCA955x SoCs.

Cc: Rodriguez, Luis <rodrigue@qca.qualcomm.com>
Cc: Giori, Kathy <kgiori@qca.qualcomm.com>
Cc: QCA Linux Team <qca-linux-team@qca.qualcomm.com>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4945/
Signed-off-by: John Crispin <blogic@openwrt.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c
index 579f452c0b45..555e603de619 100644
--- a/arch/mips/ath79/clock.c
+++ b/arch/mips/ath79/clock.c
@@ -295,6 +295,82 @@ static void __init ar934x_clocks_init(void)
 	iounmap(dpll_base);
 }
 
+static void __init qca955x_clocks_init(void)
+{
+	u32 pll, out_div, ref_div, nint, frac, clk_ctrl, postdiv;
+	u32 cpu_pll, ddr_pll;
+	u32 bootstrap;
+
+	bootstrap = ath79_reset_rr(QCA955X_RESET_REG_BOOTSTRAP);
+	if (bootstrap &	QCA955X_BOOTSTRAP_REF_CLK_40)
+		ath79_ref_clk.rate = 40 * 1000 * 1000;
+	else
+		ath79_ref_clk.rate = 25 * 1000 * 1000;
+
+	pll = ath79_pll_rr(QCA955X_PLL_CPU_CONFIG_REG);
+	out_div = (pll >> QCA955X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+		  QCA955X_PLL_CPU_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA955X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+		  QCA955X_PLL_CPU_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA955X_PLL_CPU_CONFIG_NINT_SHIFT) &
+	       QCA955X_PLL_CPU_CONFIG_NINT_MASK;
+	frac = (pll >> QCA955X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+	       QCA955X_PLL_CPU_CONFIG_NFRAC_MASK;
+
+	cpu_pll = nint * ath79_ref_clk.rate / ref_div;
+	cpu_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 6));
+	cpu_pll /= (1 << out_div);
+
+	pll = ath79_pll_rr(QCA955X_PLL_DDR_CONFIG_REG);
+	out_div = (pll >> QCA955X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+		  QCA955X_PLL_DDR_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA955X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+		  QCA955X_PLL_DDR_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA955X_PLL_DDR_CONFIG_NINT_SHIFT) &
+	       QCA955X_PLL_DDR_CONFIG_NINT_MASK;
+	frac = (pll >> QCA955X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+	       QCA955X_PLL_DDR_CONFIG_NFRAC_MASK;
+
+	ddr_pll = nint * ath79_ref_clk.rate / ref_div;
+	ddr_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 10));
+	ddr_pll /= (1 << out_div);
+
+	clk_ctrl = ath79_pll_rr(QCA955X_PLL_CLK_CTRL_REG);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_CPU_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_CPU_PLL_BYPASS)
+		ath79_cpu_clk.rate = ath79_ref_clk.rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_CPUCLK_FROM_CPUPLL)
+		ath79_cpu_clk.rate = ddr_pll / (postdiv + 1);
+	else
+		ath79_cpu_clk.rate = cpu_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_DDR_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_DDR_PLL_BYPASS)
+		ath79_ddr_clk.rate = ath79_ref_clk.rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_DDRCLK_FROM_DDRPLL)
+		ath79_ddr_clk.rate = cpu_pll / (postdiv + 1);
+	else
+		ath79_ddr_clk.rate = ddr_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_AHB_PLL_BYPASS)
+		ath79_ahb_clk.rate = ath79_ref_clk.rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		ath79_ahb_clk.rate = ddr_pll / (postdiv + 1);
+	else
+		ath79_ahb_clk.rate = cpu_pll / (postdiv + 1);
+
+	ath79_wdt_clk.rate = ath79_ref_clk.rate;
+	ath79_uart_clk.rate = ath79_ref_clk.rate;
+}
+
 void __init ath79_clocks_init(void)
 {
 	if (soc_is_ar71xx())
@@ -307,6 +383,8 @@ void __init ath79_clocks_init(void)
 		ar933x_clocks_init();
 	else if (soc_is_ar934x())
 		ar934x_clocks_init();
+	else if (soc_is_qca955x())
+		qca955x_clocks_init();
 	else
 		BUG();