diff options
Diffstat (limited to 'arch/arm/mach-ux500/uart-db8500.c')
-rw-r--r-- | arch/arm/mach-ux500/uart-db8500.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/uart-db8500.c b/arch/arm/mach-ux500/uart-db8500.c new file mode 100644 index 00000000000..fad9b9a13df --- /dev/null +++ b/arch/arm/mach-ux500/uart-db8500.c @@ -0,0 +1,225 @@ +/* + * Copyright (C) ST-Ericsson SA 2011 + * + * Author: Arun R Murthy <arun.murthy@stericsson.com>, + * Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/amba/serial.h> +#include <mach/setup.h> +#include <mach/hardware.h> +#include <mach/context.h> + +#ifdef CONFIG_UX500_CONTEXT + +static struct { + struct clk *uart_clk; + void __iomem *base; + /* dr */ + /* rsr_err */ + u32 dma_wm; + u32 timeout; + /* fr */ + u32 lcrh_rx; + u32 ilpr; + u32 ibrd; + u32 fbrd; + u32 lcrh_tx; + u32 cr; + u32 ifls; + u32 imsc; + /* ris */ + /* mis */ + /* icr */ + u32 dmacr; + u32 xfcr; + u32 xon1; + u32 xon2; + u32 xoff1; + u32 xoff2; + /* itcr */ + /* itip */ + /* itop */ + /* tdr */ + u32 abcr; + /* absr */ + /* abfmt */ + /* abdr */ + /* abdfr */ + /* abmr */ + u32 abimsc; + /* abris */ + /* abmis */ + /* abicr */ + /* id_product_h_xy */ + /* id_provider */ + /* periphid0 */ + /* periphid1 */ + /* periphid2 */ + /* periphid3 */ + /* pcellid0 */ + /* pcellid1 */ + /* pcellid2 */ + /* pcellid3 */ +} context_uart; + +static void save_uart(void) +{ + void __iomem *membase; + + membase = context_uart.base; + + clk_enable(context_uart.uart_clk); + + context_uart.dma_wm = readl_relaxed(membase + ST_UART011_DMAWM); + context_uart.timeout = readl_relaxed(membase + ST_UART011_TIMEOUT); + context_uart.lcrh_rx = readl_relaxed(membase + ST_UART011_LCRH_RX); + context_uart.ilpr = readl_relaxed(membase + UART01x_ILPR); + context_uart.ibrd = readl_relaxed(membase + UART011_IBRD); + context_uart.fbrd = readl_relaxed(membase + UART011_FBRD); + context_uart.lcrh_tx = readl_relaxed(membase + ST_UART011_LCRH_TX); + context_uart.cr = readl_relaxed(membase + UART011_CR); + context_uart.ifls = readl_relaxed(membase + UART011_IFLS); + context_uart.imsc = readl_relaxed(membase + UART011_IMSC); + context_uart.dmacr = readl_relaxed(membase + UART011_DMACR); + context_uart.xfcr = readl_relaxed(membase + ST_UART011_XFCR); + context_uart.xon1 = readl_relaxed(membase + ST_UART011_XON1); + context_uart.xon2 = readl_relaxed(membase + ST_UART011_XON2); + context_uart.xoff1 = readl_relaxed(membase + ST_UART011_XOFF1); + context_uart.xoff2 = readl_relaxed(membase + ST_UART011_XOFF2); + context_uart.abcr = readl_relaxed(membase + ST_UART011_ABCR); + context_uart.abimsc = readl_relaxed(membase + ST_UART011_ABIMSC); + + clk_disable(context_uart.uart_clk); +} + +static void restore_uart(void) +{ + int cnt; + int retries = 100; + unsigned int cr; + void __iomem *membase; + u16 dummy; + bool show_warn = false; + + membase = context_uart.base; + clk_enable(context_uart.uart_clk); + + writew_relaxed(context_uart.ifls, membase + UART011_IFLS); + cr = UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_LBE; + + writew_relaxed(cr, membase + UART011_CR); + writew_relaxed(0, membase + UART011_FBRD); + writew_relaxed(1, membase + UART011_IBRD); + writew_relaxed(0, membase + ST_UART011_LCRH_RX); + if (context_uart.lcrh_tx != ST_UART011_LCRH_RX) { + int i; + /* + * Wait 10 PCLKs before writing LCRH_TX register, + * to get this delay write read only register 10 times + */ + for (i = 0; i < 10; ++i) + dummy = readw(membase + ST_UART011_LCRH_RX); + writew_relaxed(0, membase + ST_UART011_LCRH_TX); + } + writew(0, membase + UART01x_DR); + do { + if (!(readw(membase + UART01x_FR) & UART01x_FR_BUSY)) + break; + cpu_relax(); + } while (retries-- > 0); + if (retries < 0) + /* + * We can't print out a warning here since the uart is + * not fully restored. Do it later. + */ + show_warn = true; + + writel_relaxed(context_uart.dma_wm, membase + ST_UART011_DMAWM); + writel_relaxed(context_uart.timeout, membase + ST_UART011_TIMEOUT); + writel_relaxed(context_uart.lcrh_rx, membase + ST_UART011_LCRH_RX); + writel_relaxed(context_uart.ilpr, membase + UART01x_ILPR); + writel_relaxed(context_uart.ibrd, membase + UART011_IBRD); + writel_relaxed(context_uart.fbrd, membase + UART011_FBRD); + /* + * Wait 10 PCLKs before writing LCRH_TX register, + * to get this delay write read only register 10-3 + * times, as already there are 3 writes after + * ST_UART011_LCRH_RX + */ + for (cnt = 0; cnt < 7; cnt++) + dummy = readw(membase + ST_UART011_LCRH_RX); + + writel_relaxed(context_uart.lcrh_tx, membase + ST_UART011_LCRH_TX); + writel_relaxed(context_uart.ifls, membase + UART011_IFLS); + writel_relaxed(context_uart.dmacr, membase + UART011_DMACR); + writel_relaxed(context_uart.xfcr, membase + ST_UART011_XFCR); + writel_relaxed(context_uart.xon1, membase + ST_UART011_XON1); + writel_relaxed(context_uart.xon2, membase + ST_UART011_XON2); + writel_relaxed(context_uart.xoff1, membase + ST_UART011_XOFF1); + writel_relaxed(context_uart.xoff2, membase + ST_UART011_XOFF2); + writel_relaxed(context_uart.abcr, membase + ST_UART011_ABCR); + writel_relaxed(context_uart.abimsc, membase + ST_UART011_ABIMSC); + writel_relaxed(context_uart.cr, membase + UART011_CR); + writel(context_uart.imsc, membase + UART011_IMSC); + + clk_disable(context_uart.uart_clk); + + if (show_warn) + pr_warning("%s:uart tx busy\n", __func__); +} + +static int uart_context_notifier_call(struct notifier_block *this, + unsigned long event, void *data) +{ + switch (event) { + case CONTEXT_APE_SAVE: + save_uart(); + break; + + case CONTEXT_APE_RESTORE: + restore_uart(); + break; + } + return NOTIFY_OK; +} + +static struct notifier_block uart_context_notifier = { + .notifier_call = uart_context_notifier_call, +}; + +#define __UART_BASE(soc, x) soc##_UART##x##_BASE +#define UART_BASE(soc, x) __UART_BASE(soc, x) + +static int __init uart_context_notifier_init(void) +{ + unsigned long base; + static const char clkname[] __initconst + = "uart" __stringify(CONFIG_UX500_DEBUG_UART); + + if (cpu_is_u8500()) + base = UART_BASE(U8500, CONFIG_UX500_DEBUG_UART); + else if (cpu_is_u5500()) + base = UART_BASE(U5500, CONFIG_UX500_DEBUG_UART); + else + ux500_unknown_soc(); + + context_uart.base = ioremap(base, SZ_4K); + context_uart.uart_clk = clk_get_sys(clkname, NULL); + + if (IS_ERR(context_uart.uart_clk)) { + pr_err("%s:unable to get clk-uart%d\n", __func__, + CONFIG_UX500_DEBUG_UART); + return -EINVAL; + } + + return WARN_ON(context_ape_notifier_register(&uart_context_notifier)); +} +arch_initcall(uart_context_notifier_init); +#endif |