[PATCH v2 1/5] clk: Add clock driver for ASPEED BMC SoCs

From: Joel Stanley
Date: Thu Sep 21 2017 - 00:27:16 EST


This adds the stub of a driver for the ASPEED SoCs. The clocks are
defined and the static registration is set up.

Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/clk/Kconfig | 12 +++
drivers/clk/Makefile | 1 +
drivers/clk/clk-aspeed.c | 162 +++++++++++++++++++++++++++++++
include/dt-bindings/clock/aspeed-clock.h | 43 ++++++++
4 files changed, 218 insertions(+)
create mode 100644 drivers/clk/clk-aspeed.c
create mode 100644 include/dt-bindings/clock/aspeed-clock.h

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 1c4e1aa6767e..9abe063ef8d2 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -142,6 +142,18 @@ config COMMON_CLK_GEMINI
This driver supports the SoC clocks on the Cortina Systems Gemini
platform, also known as SL3516 or CS3516.

+config COMMON_CLK_ASPEED
+ bool "Clock driver for Aspeed BMC SoCs"
+ depends on ARCH_ASPEED || COMPILE_TEST
+ default ARCH_ASPEED
+ select MFD_SYSCON
+ select RESET_CONTROLLER
+ ---help---
+ This driver supports the SoC clocks on the Aspeed BMC platforms.
+
+ The G4 and G5 series, including the ast2400 and ast2500, are supported
+ by this driver.
+
config COMMON_CLK_S2MPS11
tristate "Clock driver for S2MPS1X/S5M8767 MFD"
depends on MFD_SEC_CORE || COMPILE_TEST
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index c99f363826f0..575c68919d9b 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
obj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
obj-$(CONFIG_COMMON_CLK_GEMINI) += clk-gemini.o
+obj-$(CONFIG_COMMON_CLK_ASPEED) += clk-aspeed.o
obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
obj-$(CONFIG_CLK_HSDK) += clk-hsdk-pll.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
new file mode 100644
index 000000000000..824c54767009
--- /dev/null
+++ b/drivers/clk/clk-aspeed.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright 2017 IBM Corporation
+ *
+ * Joel Stanley <joel@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "clk-aspeed: " fmt
+
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/clock/aspeed-clock.h>
+
+#define ASPEED_RESET_CTRL 0x04
+#define ASPEED_CLK_SELECTION 0x08
+#define ASPEED_CLK_STOP_CTRL 0x0c
+#define ASPEED_MPLL_PARAM 0x20
+#define ASPEED_HPLL_PARAM 0x24
+#define ASPEED_MISC_CTRL 0x2c
+#define ASPEED_STRAP 0x70
+
+/* Keeps track of all clocks */
+static struct clk_hw_onecell_data *aspeed_clk_data;
+
+static void __iomem *scu_base;
+
+/**
+ * struct aspeed_gate_data - Aspeed gated clocks
+ * @clock_idx: bit used to gate this clock in the clock register
+ * @reset_idx: bit used to reset this IP in the reset register. -1 if no
+ * reset is required when enabling the clock
+ * @name: the clock name
+ * @parent_name: the name of the parent clock
+ * @flags: standard clock framework flags
+ */
+struct aspeed_gate_data {
+ u8 clock_idx;
+ s8 reset_idx;
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+};
+
+/**
+ * struct aspeed_clk_gate - Aspeed specific clk_gate structure
+ * @hw: handle between common and hardware-specific interfaces
+ * @reg: register controlling gate
+ * @clock_idx: bit used to gate this clock in the clock register
+ * @reset_idx: bit used to reset this IP in the reset register. -1 if no
+ * reset is required when enabling the clock
+ * @flags: hardware-specific flags
+ * @lock: register lock
+ *
+ * Some of the clocks in the Aspeed SoC must be put in reset before enabling.
+ * This modified version of clk_gate allows an optional reset bit to be
+ * specified.
+ */
+struct aspeed_clk_gate {
+ struct clk_hw hw;
+ struct regmap *map;
+ u8 clock_idx;
+ s8 reset_idx;
+ u8 flags;
+ spinlock_t *lock;
+};
+
+#define to_aspeed_clk_gate(_hw) container_of(_hw, struct aspeed_clk_gate, hw)
+
+/* TODO: ask Aspeed about the actual parent data */
+static const struct aspeed_gate_data aspeed_gates[] __initconst = {
+/* clk rst name parent flags */
+ { 0, -1, "eclk-gate", "eclk", 0 }, /* Video Engine */
+ { 1, 7, "gclk-gate", NULL, 0 }, /* 2D engine */
+ { 2, -1, "mclk-gate", "mpll", CLK_IS_CRITICAL }, /* SDRAM */
+ { 3, 6, "vclk-gate", NULL, 0 }, /* Video Capture */
+ { 4, 10, "bclk-gate", "bclk", 0 }, /* PCIe/PCI */
+ { 5, -1, "dclk-gate", NULL, 0 }, /* DAC */
+ { 6, -1, "refclk-gate", "clkin", CLK_IS_CRITICAL },
+ { 7, 3, "usb-port2-gate", NULL, 0 }, /* USB2.0 Host port 2 */
+ { 8, 5, "lclk-gate", NULL, 0 }, /* LPC */
+ { 9, 15, "usb-uhci-gate", NULL, 0 }, /* USB1.1 (requires port 2 enabled) */
+ { 10, 13, "d1clk-gate", NULL, 0 }, /* GFX CRT */
+ /* 11: reserved */
+ /* 12: reserved */
+ { 13, 4, "yclk-gate", NULL, 0 }, /* HAC */
+ { 14, 14, "usb-port1-gate", NULL, 0 }, /* USB2 hub/USB2 host port 1/USB1.1 dev */
+ { 15, -1, "uart1clk-gate", "uart", 0 }, /* UART1 */
+ { 16, -1, "uart2clk-gate", "uart", 0 }, /* UART2 */
+ { 17, -1, "uart5clk-gate", "uart", 0 }, /* UART5 */
+ /* 18: reserved */
+ { 19, -1, "espiclk-gate", NULL, 0 }, /* eSPI */
+ { 20, 11, "mac1clk-gate", "clkin", 0 }, /* MAC1 */
+ { 21, 12, "mac2clk-gate", "clkin", 0 }, /* MAC2 */
+ /* 22: reserved */
+ /* 23: reserved */
+ { 24, -1, "rsaclk-gate", NULL, 0 }, /* RSA */
+ { 25, -1, "uart3clk-gate", "uart", 0 }, /* UART3 */
+ { 26, -1, "uart4clk-gate", "uart", 0 }, /* UART4 */
+ { 27, 16, "sdclk-gate", NULL, 0 }, /* SDIO/SD */
+ { 28, -1, "lhclk-gate", "lhclk", 0 }, /* LPC master/LPC+ */
+ /* 29: reserved */
+ /* 30: reserved */
+ /* 31: reserved */
+};
+
+static void __init aspeed_cc_init(struct device_node *np)
+{
+ struct regmap *map;
+ u32 val;
+ int ret;
+ int i;
+
+ scu_base = of_iomap(np, 0);
+ if (IS_ERR(scu_base))
+ return;
+
+ aspeed_clk_data = kzalloc(sizeof(*aspeed_clk_data) +
+ sizeof(*aspeed_clk_data->hws) * ASPEED_NUM_CLKS,
+ GFP_KERNEL);
+ if (!aspeed_clk_data)
+ return;
+
+ /*
+ * This way all clock fetched before the platform device probes,
+ * except those we assign here for early use, will be deferred.
+ */
+ for (i = 0; i < ASPEED_NUM_CLKS; i++)
+ aspeed_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
+
+ map = syscon_node_to_regmap(np);
+ if (IS_ERR(map)) {
+ pr_err("no syscon regmap\n");
+ return;
+ }
+ /*
+ * We check that the regmap works on this very first access,
+ * but as this is an MMIO-backed regmap, subsequent regmap
+ * access is not going to fail and we skip error checks from
+ * this point.
+ */
+ ret = regmap_read(map, ASPEED_STRAP, &val);
+ if (ret) {
+ pr_err("failed to read strapping register\n");
+ return;
+ }
+
+ aspeed_clk_data->num = ASPEED_NUM_CLKS;
+ ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, aspeed_clk_data);
+ if (ret)
+ pr_err("failed to add DT provider: %d\n", ret);
+};
+CLK_OF_DECLARE_DRIVER(aspeed_cc_g5, "aspeed,ast2500-scu", aspeed_cc_init);
+CLK_OF_DECLARE_DRIVER(aspeed_cc_g4, "aspeed,ast2400-scu", aspeed_cc_init);
diff --git a/include/dt-bindings/clock/aspeed-clock.h b/include/dt-bindings/clock/aspeed-clock.h
new file mode 100644
index 000000000000..afe06b77562d
--- /dev/null
+++ b/include/dt-bindings/clock/aspeed-clock.h
@@ -0,0 +1,43 @@
+#ifndef DT_BINDINGS_ASPEED_CLOCK_H
+#define DT_BINDINGS_ASPEED_CLOCK_H
+
+#define ASPEED_NUM_CLKS 34
+
+#define ASPEED_CLK_HPLL 0
+#define ASPEED_CLK_AHB 1
+#define ASPEED_CLK_APB 2
+#define ASPEED_CLK_UART 3
+#define ASPEED_CLK_SDIO 4
+#define ASPEED_CLK_ECLK 5
+#define ASPEED_CLK_ECLK_MUX 6
+#define ASPEED_CLK_LHCLK 7
+#define ASPEED_CLK_MAC 8
+#define ASPEED_CLK_BCLK 9
+#define ASPEED_CLK_MPLL 10
+#define ASPEED_CLK_GATES 11
+#define ASPEED_CLK_GATE_ECLK (0 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_GCLK (1 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_MCLK (2 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_VCLK (3 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_BCLK (4 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_DCLK (5 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_REFCLK (6 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_USBPORT2CLK (7 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_LCLK (8 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_USBUHCICLK (9 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_D1CLK (10 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_YCLK (11 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_USBPORT1CLK (12 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_UART1CLK (13 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_UART2CLK (14 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_UART5CLK (15 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_ESPICLK (16 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_MAC1CLK (17 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_MAC2CLK (18 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_RSACLK (19 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_UART3CLK (20 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_UART4CLK (21 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_SDCLKCLK (22 + ASPEED_CLK_GATES)
+#define ASPEED_CLK_GATE_LHCCLK (23 + ASPEED_CLK_GATES)
+
+#endif
--
2.14.1