clk: Add clock driver for ASPEED BMC SoCs

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

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 1c4e1aa..9abe063 100644 (file)
--- 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 f7f761b..d260da4 100644 (file)
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -27,6 +27,7 @@ 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 (file)
index 0000000..7a86ee0
--- /dev/null
+++ b/drivers/clk/clk-aspeed.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#define pr_fmt(fmt) "clk-aspeed: " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <dt-bindings/clock/aspeed-clock.h>
+
+#define ASPEED_NUM_CLKS                35
+
+#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[] = {
+       /*                               clk rst   name                 parent  flags */
+       [ASPEED_CLK_GATE_ECLK] =        {  0, -1, "eclk-gate",          "eclk", 0 }, /* Video Engine */
+       [ASPEED_CLK_GATE_GCLK] =        {  1,  7, "gclk-gate",          NULL,   0 }, /* 2D engine */
+       [ASPEED_CLK_GATE_MCLK] =        {  2, -1, "mclk-gate",          "mpll", CLK_IS_CRITICAL }, /* SDRAM */
+       [ASPEED_CLK_GATE_VCLK] =        {  3,  6, "vclk-gate",          NULL,   0 }, /* Video Capture */
+       [ASPEED_CLK_GATE_BCLK] =        {  4, 10, "bclk-gate",          "bclk", 0 }, /* PCIe/PCI */
+       [ASPEED_CLK_GATE_DCLK] =        {  5, -1, "dclk-gate",          NULL,   0 }, /* DAC */
+       [ASPEED_CLK_GATE_REFCLK] =      {  6, -1, "refclk-gate",        "clkin", CLK_IS_CRITICAL },
+       [ASPEED_CLK_GATE_USBPORT2CLK] = {  7,  3, "usb-port2-gate",     NULL,   0 }, /* USB2.0 Host port 2 */
+       [ASPEED_CLK_GATE_LCLK] =        {  8,  5, "lclk-gate",          NULL,   0 }, /* LPC */
+       [ASPEED_CLK_GATE_USBUHCICLK] =  {  9, 15, "usb-uhci-gate",      NULL,   0 }, /* USB1.1 (requires port 2 enabled) */
+       [ASPEED_CLK_GATE_D1CLK] =       { 10, 13, "d1clk-gate",         NULL,   0 }, /* GFX CRT */
+       [ASPEED_CLK_GATE_YCLK] =        { 13,  4, "yclk-gate",          NULL,   0 }, /* HAC */
+       [ASPEED_CLK_GATE_USBPORT1CLK] = { 14, 14, "usb-port1-gate",     NULL,   0 }, /* USB2 hub/USB2 host port 1/USB1.1 dev */
+       [ASPEED_CLK_GATE_UART1CLK] =    { 15, -1, "uart1clk-gate",      "uart", 0 }, /* UART1 */
+       [ASPEED_CLK_GATE_UART2CLK] =    { 16, -1, "uart2clk-gate",      "uart", 0 }, /* UART2 */
+       [ASPEED_CLK_GATE_UART5CLK] =    { 17, -1, "uart5clk-gate",      "uart", 0 }, /* UART5 */
+       [ASPEED_CLK_GATE_ESPICLK] =     { 19, -1, "espiclk-gate",       NULL,   0 }, /* eSPI */
+       [ASPEED_CLK_GATE_MAC1CLK] =     { 20, 11, "mac1clk-gate",       "mac",  0 }, /* MAC1 */
+       [ASPEED_CLK_GATE_MAC2CLK] =     { 21, 12, "mac2clk-gate",       "mac",  0 }, /* MAC2 */
+       [ASPEED_CLK_GATE_RSACLK] =      { 24, -1, "rsaclk-gate",        NULL,   0 }, /* RSA */
+       [ASPEED_CLK_GATE_UART3CLK] =    { 25, -1, "uart3clk-gate",      "uart", 0 }, /* UART3 */
+       [ASPEED_CLK_GATE_UART4CLK] =    { 26, -1, "uart4clk-gate",      "uart", 0 }, /* UART4 */
+       [ASPEED_CLK_GATE_SDCLKCLK] =    { 27, 16, "sdclk-gate",         NULL,   0 }, /* SDIO/SD */
+       [ASPEED_CLK_GATE_LHCCLK] =      { 28, -1, "lhclk-gate",         "lhclk", 0 }, /* LPC master/LPC+ */
+};
+
+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 clocks 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);